Abstract:
A number of frames in a burst is adjusted such that a first optimal number of first frames from a first manufacturer are included in the burst, the first optimal number of frames chosen to enable the detection of the burst by first receivers that are tuned to receive the first frames from the first manufacturer. The number of frames in the burst is adjusted such that a second optimal number of second frames from a second manufacturer are included in the burst, the second optimal number of frames chosen to enable detection of the burst by second receivers that are tuned to receive the second frames from the second manufacturer. The number of frames in the burst maintains a configuration compliant with government regulations regarding one or more of a burst length and a power emission.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This patent is a continuation of US application 20130038442 entitled “Apparatus and Method for Activating a Localization Process for a Tire pressure Monitor,” the disclosure of which is incorporated herein by reference in its entirety. This patent also incorporates herein by reference in their entirety the disclosures of US application 20130038441 entitled “Protocol Arrangement in a Tire Pressure Monitoring System”, US application 20130038443 entitled “Protocol Misinterpretation Avoidance Apparatus and Method for a Tire Pressure Monitoring System”, and US application 20130038440 entitled “Tire Pressure Monitoring Apparatus and Method”. 
     TECHNICAL FIELD 
     The technical field relates to tire pressure monitoring devices that utilize potentially different transmission protocols. 
     BACKGROUND 
     The pressure and other operating parameters of tires are important concerns when operating a vehicle. Not only can incorrect tire pressure (or the incorrect setting of some other tire parameter) lead to inefficient vehicle operation (e.g., the waste of fuel and other problems leading to higher operating costs), but too low a tire pressure (or an inadequate value for some other tire parameter) can lead to safety problems such as accidents. It is difficult and sometimes time-consuming for users to manually measure tire pressure (or other parameters) with a pressure gauge (or other instruments). Consequently, automatic tire pressure monitoring systems have been devised and these systems free the user from manually making tire measurements. 
     An automatic tire pressure monitoring device typically mounts to a wheel within the tire and wirelessly transmits information indicative of conditions within the tire. The transmissions and the order of information are typically defined by a protocol corresponding to a receiver within the vehicle. Once the receiver receives the information, the information can be processed and presented to a user. For instance, a user can be warned when the pressure in the tires is too high or too low and thus avoid safety problems. Each automobile manufacturer typically has a unique, preferred, and pre-defined protocol to meet application specific needs and applications. Consequently, receivers using one manufacturers&#39; protocol are not responsive to transmitters operating according to other manufacturers&#39; protocols. 
     Tire pressure monitors also typically need to be activated and/or initialized. Various portable tools can be used for this purpose. Unfortunately, a particular type of tire pressure monitoring device needs to operate with a tool that is compatible with that device. A user has to ensure that the two devices are compatible, or the tire pressure monitor cannot be initialized and/or activated. Consequently, a user needs to worry about compatibility issues and under some circumstances (e.g., when a mismatch is made by the user) the tire pressure monitor cannot be initialized. This results in user dissatisfaction with these previous approaches. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  comprises a block diagram of a tire pressure monitoring system according to various embodiments of the present invention; 
         FIG. 2  comprises a flowchart showing one example of an approach for initializing and/or activating a tire pressure monitor according to various embodiments of the present invention; 
         FIG. 3  comprises a flowchart showing one example of an approach for initializing and/or activating a tire pressure monitor according to various embodiments of the present invention; 
         FIG. 4  comprises a block diagram of a tire monitor according to various embodiments of the present invention; 
         FIG. 5  comprises a block diagram of timeline showing sensing patterns for a receiver device according to various embodiments of the present invention; 
         FIG. 6  comprises a block diagram of a tire pressure monitoring system according to various embodiments of the present invention; 
         FIG. 7  comprises a flowchart showing one example of an approach for monitoring pressure and/or other parameters of a tire according to various embodiments of the present invention; 
         FIG. 8  comprises a block diagram of another example of a tire pressure monitoring system according to various embodiments of the present invention; 
         FIG. 9  comprises a block diagram of transmission burst formats according to various embodiments of the present invention; 
         FIG. 10  comprises a block diagram of a burst diagram showing protocol arrangement according to various embodiments of the present invention; 
         FIG. 11  comprises a timing diagram for signals sent from the various wheel units of a vehicle according to various embodiments of the present invention. 
     
    
    
     Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein. 
     DETAILED DESCRIPTION 
     Approaches are provided where a tire pressure monitoring device can receive and recognize activation signals from a plurality of activation sources, each of these sources potentially transmitting according to different formats, different data contents, and/or different protocols. Consequently, according to the present approaches a user does not have to ensure that a particular activation device is compatible with a particular tire pressure monitor. In fact, the user can simply install the tire pressure monitor described herein and activate the device without worrying about compatibility. In one aspect, the approaches described herein can achieve compatibility in the sense that all activation devices can be accommodated. In another aspect, a subset of all possible activation devices can be accommodated, such as the most popular devices to mention one example. By “activation” and as used herein it is meant that a process is executed upon the tire pressure monitor being “activated.” For example, a localization process can be executed. In another example, a control program that transmits RF frames can be executed. Other examples are possible. 
     In many of these embodiments, a receiver device is tuned to monitor first transmissions at a first time according to a first criterion and to monitor transmissions at a second time according to a second criterion. When the receiver device initially recognizes one of the first transmissions being transmitted according to the first criterion or the second transmissions being transmitted according to the second criterion, the recognized transmission is verified as being valid or authentic. When the transmission is recognized as valid or authentic, an indication is sent to a receiver (e.g., a control unit in a vehicle) and this is effective to activate a localization process that in turn ensures that tire pressure monitoring information can be correlated to a particular tire (with a known identifier) at a known location. 
     In one aspect, the first criterion describes a low frequency (LF) sinusoidal waveform and the second criterion describes a low frequency (LF) transmission of a predetermined data pattern. Other examples are possible. In another aspect, the verifying includes verifying that the recognized transmission is received for a predetermined time period. 
     In other aspects, the sensitivity of the receiver device in the monitor can be dynamically adjusted. For example, it can be lowered when the vehicle is not moving and increased when the vehicle is moving. 
     The transmission of the tire pressure information may be accomplished in a variety of different ways. For instance, a control program may be executed to transmit the tire pressure information according to each of a plurality of communications formats incorporated into the control program and not according to a manufacturers&#39; code. Transmissions may be made according to each and every possible manufacturers&#39; protocol or a subset of these protocols. Other examples of transmission approaches are possible. 
     In others of these embodiments, an apparatus (e.g., a tire pressure monitor) includes a receiver device, a transmitter apparatus, and a controller. The receiver device is configured to receive first transmission and second transmissions from an activation source or sources. 
     The controller is coupled to the transmitter apparatus and the receiver device. The controller is configured to tune the receiver device to monitor first transmissions at a first time according to a first criterion and to monitor transmissions at a second time according to a second criteria. The controller is further configured to when the receiver device initially recognizes one of the first transmissions being transmitted according to the first criterion or the second transmissions being transmitted according to the second criterion, to verify that the recognized transmission is valid. The controller is still further configured to when the transmission is recognized as valid, send an indication to a receiver so that a localization process can be accomplished. Once the localization process is accomplished, tire pressure information that is sent can be associated with a monitor at a known location. 
     Thus, approaches are provided where a tire pressure monitoring device can receive and recognize activation signals from a plurality of sources, each of these sources potentially transmitting according to different formats, different data contents, and/or different protocols. Consequently, according to the present approaches a user does not have to ensure that a particular activation device is compatible with a particular tire pressure monitor and the user can simply install the monitor and automatically activate the localization process associated with the device without concerns about compatibility. 
     Referring to  FIG. 1 , a tire pressure monitoring system  100  is shown assembled within a vehicle  102 . The system  100  includes a receiver  106  that receives communications from tire pressure monitoring devices  104  (“monitors”) assembled within each of the vehicle&#39;s tires  108 . The receiver  106  may be any communication device configured to receive any type of transmitted communication but tuned to only recognize some of these communications. In one example, these communications are radio frequency (RF) communications, but other types of communications are also possible. 
     Although the device  104  is described as a tire pressure monitoring device herein, it will be appreciated that this device can gather and transmit other types of information related to the tire in addition to or in place of tire pressure information. For example, the information can include temperature information, acceleration information, or information related to the wear of the treads of the tire. Appropriate sensors or sensing devices may be used to obtain this information. Other examples of information may also be gathered by the tire pressure monitoring device  104 . 
     Each of the tire pressure monitoring devices  104  are assembled within the tires  108  of the vehicle  102  and, as mentioned, communicate information indicative of conditions within the tires  108  to the receiver  106 . These conditions include temperature, pressure, and/or any other desired information that aids in the evaluation of tire conditions. Other examples of conditions may also be sensed. 
     The system  100  includes the tire pressure monitoring devices  104  that in this example includes a memory device  126 . The memory device  126  is utilized for the storage of a control program  128 . The control program  128 , once compiled and executed, transmits sensed information (e.g., tire pressure information) according to one or more protocols (or formats) that govern operation and communication between the tire pressure monitoring device  104  and the receiver  106 . Examples of communication protocols that may be used include protocols that specify the frequency and timing of transmissions from the tire pressure monitoring device  104  to the receiver  106  or the format of transmission (such as what constitutes a “1” or a “0,” modulation type, error detection and/or correction content, synchronization pattern, and so forth to name but a few examples in these regards). Tire pressure monitoring information may be transmitted according to the protocols sequentially (e.g., using the same antenna) or at the same time (e.g., using different antennas). No separate manufacturers&#39; codes are used in making the transmissions. Once the control program is compiled, the protocols that have been selected cannot be changed without changing (e.g., editing, compiling, and installing anew) the control program  128 . In one aspect, the control program  128  is compiled and stored in the memory  126  during manufacturing. 
     In one aspect, the control program  128  may be executed continuously whenever the vehicle is moving. The control program  128  may also be executed when the vehicle is not moving, but only when the sensor is activated externally (i.e., via LF or grounding of a pin on the ASIC during manufacturing). At other times, it may not be executed. However, learning the identities of the devices  104  and/or determining where each device is located (“localization”, e.g., front left, front right, and so forth) may be accomplished by using an activation device  120 . The activation device  120  emits a wireless signal  122  (e.g., an LF signal) that is received by a corresponding one of the tire pressure monitoring devices  104 . Receipt of the wireless signal  122  causes the device  104  to transmit identity information and also indicate to the receiver  106  that the device  104  has received an LF signal and that the localization process can occur. When the vehicle is moving, LF transmitters (e.g., antennas) may transmit LF signals (in place of the device  120 ). When moving, the RF signals are periodically being transmitted and when the device  104  finds an LF signal, it so indicates to the receiver  106  (e.g., by flipping a bit in the RF transmission). Once this indication is received, localization can be completed (e.g., this process may occur for a predetermined amount of time to ensure that the device  104  is correctly localized). Once localization is complete, tire pressure information can be associated with a known tire. It will be appreciated that in other examples, the control program may itself be activated by the LF signals. 
     The activation device  120  includes a series of selectable buttons  124  (or other types of actuators) that are actuated by a user to indicate that they wish to activate the tire pressure monitoring device. Although the example device  120  is shown with buttons, other display and selection configurations, such as touch screens, switches or some other selection interface may be used as will be appreciated by those skilled in the art. Accordingly, installation of the multi-application tire pressure monitoring devices  104  optionally includes the initial step of physically activating the tire pressure monitoring devices  104  within each of the corresponding tires  108  or activate a localization process that allows tire pressure data to be associated with particular tires. 
     If an activation device is used, the activation device  120  is placed proximate to each of the tire pressure monitoring devices  104  to send a signal  122 . In one example, the signal  122  is a low frequency transmission received by the proximate tire pressure monitoring device  104 . 
     The devices  104  operate with the receiver  106  in the vehicle and the receiver  106  typically has a display (or some sort of user interface) that is configured to alert the driver when the tire pressure falls below a predetermined threshold value. As mentioned, once physically installed in the tire, the devices  104  are first “learned” by the control unit. During this process, the receiver  106  determines the particular identifiers and during or after learning, a localization process may be executed in which each of the devices  104  is associated with a particular tire. 
     During normal operation (after the sensors are learned and localized and the vehicle is moving), the device  104  senses the tire pressure and sends a radio frequency (RF) signal to the receiver  106  indicating the tire pressure. The receiver  106  can then determine if a pressure problem exists. If a problem exists, the user can be alerted so that appropriate action can be taken. As mentioned, this is all accomplished by use of a control program that is compiled, translated, and/or assembled before it is executed. In one aspect, once compiled the structure of the control program (e.g., the protocols selected) cannot be changed. Also, nothing external to the device can be input into this control program to change the structure of the control program once the control program (and the protocols specified in the control program) is compiled. It will be appreciated that although many of the examples described herein refer to a control program being executed to transmit RF frames with tire pressure information, that other approaches can also be used. For instance, systems that utilize manufacturers&#39; codes can also have their monitors localized according to the approaches described herein. 
     The devices  104  can also receive indications as to whether the vehicle is moving. For example, a signal can be sent from the control unit of the vehicle with this information. 
     Referring now to  FIG. 2 , one example of an approach for operating a tire pressure monitoring system is described. At step  201 , it is determined if the user is attempting to initialize the sensor. If the answer is affirmative, step  202  is performed and if the answer is negative, step  210  is performed. At step  202 , LF signals are received from an external activation source. The external source may be a portable or fixed device. The received signals may be sinusoidal signals of a predetermined frequency (CW) or be modulated to include information (e.g., bytes of information). Signals other that LF signals may also be used. The device verifies that the signals are what was expected. When verified, an indicator is transmitted to a receiver (e.g., a control module) that informs the receiver that the monitor has received and verified LF reception. 
     In another aspect, the type of signals received may affect the operation of the monitor. For instance if LF CW signals are received, bursts have certain formats may be sent. Other examples are possible. 
     At step  204  and upon verification, the learning process and localization process are performed. Learning refers to obtaining the identifier of a monitor and localization refers to determining where the monitor is located (e.g., front right wheel, front left wheel and so forth). The indicator transmitted by the monitor may be an RF signal of a burst of frames whereby selected ones of the frames include tire pressure information and where a specified predetermined bit is flipped (from a “0” to a “1”, or vice versa) to indicate LF was verified at the monitor. It will be appreciated that the monitor may attempt to verify reception of LF signals a predetermined number of times to ensure that the signal is valid. 
     At step  208  it is determined if a timeout has occurs (e.g., has a certain period of time passed so that RF transmissions can be halted). If the answer is affirmative, at step  212  transmissions are halted. If the answer is negative, execution continues at step  210  where it is determined whether the vehicle is moving. 
     If the answer at step  210  is negative, execution continues at step  208  as has been described above. If the answer is affirmative, then at step  214  LF signals are received from LF antennas at the vehicle and are verified as being valid activation signals. 
     At step  216 , an indicator is sent to the receiver to indicate that the monitor has received valid LF signals and the localization process is activated at the receiver (e.g., the vehicle controller). At step  218 , the RF transmissions are made and tire pressure information can be associated with a particular monitor at a known location. At step  220 , it is determined if the vehicle is stopped, in one example if it has been stopped for a predetermined period of time (e.g., 15 minutes). If the answer is negative, execution continues at step  218  and if the answer is affirmative execution continues at step  212 . 
     Referring now to  FIG. 3 , one approach for activating a tire pressure monitor is described. At step  302 , a receiver device is tuned to monitor first transmissions at a first time according to a first criterion and to monitor transmissions at a second time according to a second criterion. In one aspect, the first criterion describes a low frequency (LF) sinusoidal waveform and the second criterion describes a low frequency (LF) transmission of a predetermined data pattern. In another aspect, the verifying includes verifying that the recognized transmission is received for a predetermined time period. 
     At step  304 , when the receiver device initially recognizes one of the first transmissions being transmitted according to the first criterion or the second transmissions being transmitted according to the second criterion. At step  306 , the transmission is recognized as valid and at step  308  an indication is sent to the receiver that the monitor has received a valid LF activation signal and that the localization process can be executed. 
     After step  308  is accomplished, the tire pressure information can be associated with a known monitor that is at a known location. Consequently, reports can be generated to the user that alert the user when a tire becomes deflated, for example. It will be appreciated that in one aspect tire pressure information can be transmitted periodically when the vehicle is moving. However, it is only after localization is completed that this information can be linked with a monitor that resides at a known location. As used herein, “monitor” refers to the tire pressure monitor such as one of the devices  104  in  FIG. 1  or the device  400  of  FIG. 4 . 
     Referring now to  FIG. 4 , an apparatus  400  (e.g., a tire pressure monitor) for initializing a tire pressure monitor includes a receiver device  402 , a transmitter apparatus  404 , and a controller  406 . The receiver device  402  is configured to monitor for first transmission and second transmissions having predetermined formats (that may be present in activation signals  405 ) received from an activation source or sources  408  via the antenna  403 . 
     The controller  406  is coupled to the transmitter apparatus  404  and the receiver device  402 . The controller  406  is configured to tune the receiver device  402  using control signals  407  to monitor for first transmissions at a first time according to a first criterion and to monitor for second transmissions at a second time according to a second criterion. The controller  406  is further configured to when the receiver device  402  initially recognizes one of the first transmissions being transmitted according to the first criterion or the second transmissions being transmitted according to the second criterion, to verify that the recognized transmission is valid (e.g., it matches predetermined requirements such as being of a particular frequency, having a particular value, having a predetermined power level, and so forth). The controller  406  is still further configured to when the transmission is recognized as valid, activate the transmission apparatus  404  to transmit an indicator (e.g., a flipped bit in an RF signal  411 ) via the antenna  415 . This information  411  is transmitted to a vehicle receiver or controller  420  where it may be further processed as described above to initiate the localization process. Although the device  400  may be periodically broadcasting tire pressure information when the vehicle is moving (e.g., in bursts of frames transmitted every approximately 17 seconds) it is only after the localization process is complete that the tire pressure information can be associated with a known tire. 
     In another aspect, the sensitivity of the LF reception by the receiver device can be adjusted, i.e., it has a dynamic sensitivity. For example, the sensitivity can be lowered when the vehicle is at rest. This may be done, for example, so that when the vehicle is stopped spurious LF signals (e.g., caused by other electronic devices) are not confused as being valid signals. The sensitivity can be increased when the vehicle is moving since there is less of a chance of detecting spurious signals when the vehicle is moving down a roadway. 
     Referring now to  FIG. 5 , one example of how a receiver device (e.g., device  402  in  FIG. 4 ) in a monitor is tuned is described.  FIG. 5  shows an x-axis that represents time and the time units are expressed in arbitrary units (0, 1 . . . 23). Each time period includes the criteria that a controller (e.g., controller  406  of  FIG. 4 ) has tuned a receiver device (e.g., device  402  of  FIG. 4 ) to listen. For example, between time 0 and 1, the receiver device in the monitor is tuned to listen for LF signals that have a data content of byte 1 and byte 2. Between time 1 and 2, the receiver device in the monitor is tuned to listen for a low frequency (LF) sinusoidal signal (CW). It will be appreciated that these are examples only and that other types of signals can be listened for and in different orders. 
     Between times 8 and 9, the controller identifies the received transmission as an LF CW transmission. Between time 9 and 12 the receiver device in the monitor is configured to verify this is a valid transmission by listening for the LF CW pattern. For example, the receiver device in the monitor ensures that this is not a noise signal by verifying a constant frequency and/or amplitude to take one example, At time 12, the transmission of RF signals (e.g., using a control program) is enabled. The receiver device in the monitor then alternates between checking/listening for the byte pattern and LF CW patterns described above. 
     At times 16 and 17, the controller identifies the received transmission as one of the byte patterns byte 1 or byte 2. Between time 17 and 20 the receiver is configured to verify this is a valid transmission by listening for byte 1 or byte 2. For example, the receiver device ensures that this is not a noise signal by verifying that the values of byte 1 or byte 2 do not change. At time 20, the transmission of RF signals (e.g., using a control program) is enabled. The receiver device then alternates between checking for the byte pattern and LF CW patterns described above. 
     It will be appreciated that in this example the LF CW may be transmitted by one type of activation device (e.g., from a first manufacturer) while the LF byte transmissions are transmitted by another type of activation device (e.g., from a second manufacturer). However, these approaches are applicable to any number of possible received formats and are not limited to two as shown here. The byte patterns may be any byte pattern as is known to those skilled in the art. 
     Approaches are provided wherein a burst of frames is sent from a tire pressure monitor to a receiver and this burst is constructed to successfully transmit the frames of various manufacturers and, at the same time, meet various criteria such as manufacturers&#39; guidelines, government rules, system functionality, and noise avoidance. The approaches described herein allow the maximum amount of information to be effectively transmitted from the tire pressure monitor within the framework of various requirements. In so doing, an effective multi-application tire pressure monitoring device (e.g., that transmits frames according to the protocols of multiple manufacturers) is provided. 
     An apparatus for transmitting tire pressure signals includes a transmission buffer and a transmitter. The transmission buffer is configured to store tire pressure monitoring data. The transmitter is configured to transmit a signal including the tire pressure monitoring data. The signal includes a burst that includes plurality of frames and each of the frames includes the tire pressure monitoring information. A plurality of pause spaces may also disposed between at least some of the frames in the burst. Characteristics of the frames in the burst and of the burst itself may be selected based upon one or more criteria such as government standards, industry requirements, periodicity requirements, or power requirements. Other examples of criteria are possible. 
     The above-mentioned characteristics of the signal that are adjusted based upon the criteria may include the total number of frames in the burst, the relative positioning of the frames within the burst, the number of frames in the burst from each of plurality of manufacturers, and the relative positioning of the frames within the burst wherein at least some of the frames are from different manufacturers. Other examples of characteristics may also be adjusted. 
     In one aspect, the power requirement of the frames allows a first power level for a first burst and a second power level for a second burst, the first burst shorter than the second burst, and the first power level being greater than the second power level. In another aspect, the industry requirement relates to the amount of time required to complete a localization process. In still another aspect, the government standard relates to the maximum on-air time for a burst. 
     Referring to  FIG. 6 , a tire pressure monitoring system  600  is shown assembled within a vehicle  602 . The system  600  includes a receiver  606  that receives communications from tire pressure monitoring devices  604  (“monitors”) assembled within each of the vehicle&#39;s tires  608 . The receiver  606  may be any communication device configured to receive any type of transmitted communication but tuned to only recognize some of these communications. In one example, these communications are radio frequency (RF) communications, but other types of communications are also possible. 
     Although the device  604  is described as a tire pressure monitoring device herein, it will be appreciated that this device can gather and transmit other types of information related to the tire in addition to or in place of tire pressure information. For example, the information can include temperature information or information related to the wear of the treads of the tire. Appropriate sensors or sensing devices may be used to obtain this information. Other examples of information may also be gathered by the tire pressure monitoring device  604 . 
     Each of the tire pressure monitoring devices  604  are assembled within the tires  608  of the vehicle  602  and, as mentioned, communicate information indicative of conditions within the tires  608  to the receiver  606 . These conditions include temperature, pressure, and/or any other desired information that aids in the evaluation of tire conditions. Other examples of conditions may also be sensed. 
     The system  600  includes the tire pressure monitoring devices  604  that in this example includes a memory device  626 . The memory device  626  is utilized for the storage of a control program  628 . The control program  628 , once compiled and executed, transmits sensed information (e.g., tire pressure information) according to one or more protocols (or formats) that govern operation and communication between the tire pressure monitoring device  604  and the receiver  606 . Examples of communication protocols that may be used include protocols that specify the frequency and timing of transmissions from the tire pressure monitoring device  604  to the receiver  606  or the format of transmission (such as what constitutes a “1” or a “0,” modulation type, error detection and/or correction content, synchronization pattern, and so forth to name but a few examples in these regards). Tire pressure monitoring information may be transmitted according to the protocols sequentially (e.g., using the same antenna) or at the same time (e.g., using different antennas). No separate manufacturers&#39; codes are used in making the transmissions. Once the control program is compiled, the protocols that have been selected cannot be changed without changing (e.g., editing, compiling, and installing anew) the control program  628 . In one aspect, the control program  628  is compiled and stored in the memory  626  during manufacturing. 
     In one aspect, the control program  628  may be executed continuously whenever the vehicle is moving. The control program  628  may also be executed when the vehicle is not moving, but only when the sensor is activated externally (i.e., via LF or grounding of a pin on the ASIC during manufacturing). At other times, it may not be executed. However, learning the identities of the devices  604  and/or determining where each device is located (“localization”, e.g., front left, front right, and so forth) may be accomplished by using an activation device  620 . The activation device  620  emits a wireless signal  622  (e.g., an LF signal) that is received by a corresponding one of the tire pressure monitoring devices  604 . Receipt of the wireless signal  622  causes the device  604  to transmit identity information and also indicate to the receiver  606  that the device  604  has received an LF signal and that the localization process can occur. When the vehicle is moving, LF transmitters (e.g., antennas) may transmit LF signals (in place of the device  620 ). When moving, the RF signals are periodically being transmitted and when the device  604  finds an LF signal, it so indicates to the receiver  606  (e.g., by flipping a bit in the RF transmission). Once this indication is received, localization can be completed (e.g., this process may occur for a predetermined amount of time to ensure that the device  604  is correctly localized). Once localization is complete, tire pressure information can be associated with a known tire. It will be appreciated that in other examples, the control program may itself be activated by the LF signals. 
     The activation device  620  includes a series of selectable buttons  624  (or other types of actuators) that are actuated by a user to indicate that they wish to activate the tire pressure monitoring device. Although the example device  620  is shown with buttons, other display and selection configurations, such as touch screens, switches or some other selection interface may be used as will be appreciated by those skilled in the art. Accordingly, installation of the multi-application tire pressure monitoring devices  604  optionally includes the initial step of physically activating the tire pressure monitoring devices  604  within each of the corresponding tires  608  or activating a localization process that allows tire pressure data to be associated with particular tires. 
     If an activation device is used, the activation device  620  is placed proximate to each of the tire pressure monitoring devices  604  to send a signal  622 . In one example, the signal  622  is a low frequency transmission received by the proximate tire pressure monitoring device  604 . 
     The devices  604  operate with the receiver  606  in the vehicle and the receiver  606  typically has a display (or some sort of user interface) that is configured to alert the driver when the tire pressure falls below a predetermined threshold value. As mentioned, once physically installed in the tire, the devices  604  are first “learned” by the control unit. During this process, the receiver  606  determines the particular identifiers and during or after learning, a localization process may be executed in which each of the devices  604  is associated with a particular tire. 
     During normal operation (after the sensors are learned and localized and the vehicle is moving), the device  604  senses the tire pressure and sends a radio frequency (RF) signal to the receiver  606  indicating the tire pressure. The receiver  606  can then determine if a pressure problem exists. If a problem exists, the user can be alerted so that appropriate action can be taken. As mentioned, this is all accomplished by use of a control program that is compiled, translated, and/or assembled before it is executed. In one aspect, once compiled the structure of the control program (e.g., the protocols selected) cannot be changed. Also, nothing external to the device can be input into this control program to change the structure of the control program once the control program (and the protocols specified in the control program) is compiled. 
     As mentioned, the devices  604  transmit tire pressure information. The signals that are transmitted include bursts that themselves include plurality of frames and each of the frames includes the tire pressure monitoring information. A plurality of pause spaces may be disposed between at least some of the frames in the burst. Characteristics of the frames in the burst or of the burst itself may be configured based upon criteria such as government standards, industry requirements, receiver requirements, periodicity requirements, or power requirements. Other examples of criteria are possible. 
     The characteristics of the signal may include the total number of frames in the burst, the relative positioning of the frames within the burst, the number of frames in the burst from each of plurality of manufacturers, and the relative positioning of the frames within the burst wherein at least some of the frames are from different manufacturers. Other examples of characteristics are possible. 
     The devices  604  can also receive indications as to whether the vehicle is moving. For example, a signal can be sent from the control unit of the vehicle with this information or the device may include an accelerometer. 
     Referring now to  FIG. 7 , one example of an approach for transmitting sensed tire pressure information is described. At step  702 , the tire pressure information is sensed. This can be accomplished by any tire pressure sensing mechanism as known to those skilled in the art. 
     At step  704 , the sensed tire pressure information is stored in a transmission buffer. The transmission buffer may be part of a memory. 
     At step  706 , a control program is executed to transmit the tire pressure information from the transmission buffer to an external receiver device according to each of a plurality of communications formats incorporated into the control program and not according to a manufacturers&#39; code. The control program may be stored in the same memory as the transmission buffer or may be stored in a separate memory unit. 
     The control program may be compiled and/or assembled prior to its execution. The transmission of information according to each of the protocols may be in predetermined block having a pre-defined format. Thus, separate blocks are used to transmit tire pressure information for different protocols. Each of the blocks may be transmitted sequentially in a burst. A null space may be used to separate each of the blocks in the burst. 
     As mentioned, the transmission buffer is configured to store tire pressure monitoring data and the transmitter is configured to transmit a signal including the tire pressure monitoring data. The signal includes a burst that includes plurality of frames and each of the frames includes the tire pressure monitoring information. A plurality of pause spaces in some examples are disposed between at least some of the frames in the burst. Characteristics of the frames in the burst may be selected based upon criteria such as government standards, industry requirements, periodicity requirements, or power requirements. Other examples of criteria are possible. 
     The characteristics of the signal (e.g., that are adjusted to meet government standards, industry requirements, receiver requirements, periodicity requirements, and/or power requirements) may include the total number of frames in the burst, the relative positioning of the frames within the burst, the number of frames in the burst from each of plurality of manufacturers, and the relative positioning of the frames within the burst wherein at least some of the frames are from different manufacturers. Other examples are possible. 
     At step  708 , the external receiver device may be configured to operate according to a selected one of the plurality of communication protocols. At the external receiver device (that is configured to operate according to a selected one of the plurality of communication protocols) receives the tire pressure information transmitted. At step  710 , the receiver recognizes the tire pressure information transmitted according to the selected one of the plurality of communication protocols and ignores the tire pressure information transmitted according to others of the plurality of communication protocols. 
     Referring now to  FIG. 8 , an apparatus  800  for sensing tire pressure information is described. The apparatus  800  includes a sensor  802 , a transmission buffer  804 , a memory  806 , a transmitter  808 , and a processor  810 . One or more antennas  809  transmit RF signals with the tire pressure information (e.g., in blocks, the blocks serially transmitted in bursts, each block having a predetermined format). One or more antennas  811  receive other communications (e.g., LF communications) that activate the apparatus  800  to transmit the RF signals. 
     The sensor  802  that is configured to sense tire pressure information of a tire. The sensor  802  is any mechanical or electrical sensing arrangement that senses the pressure of the tire as know to those skilled in the art. 
     The transmission buffer  804  is communicatively coupled to the sensing device and is configured to store the sensed tire pressure information. The transmission buffer  804  may be part of the memory  806  or separate from the memory  806  and is configured to store tire pressure monitoring data. The memory  806  may be any type of memory storage device. 
     The transmitter  808  is coupled to the transmission buffer  804  and is configured to transmit signals. The transmitter  808  may have one or more antennas  809  to transmit the signals. As mentioned, one or more antennas  811  receive other communications (e.g., LF communications) that activate the apparatus  800  to transmit the RF signals. These antennas may be coupled to the processor  810 , which determines whether the signals meet criteria that are required to activate the apparatus  800  and thereby begin transmitting the tire pressure information. The signal includes a burst that includes plurality of frames and each of the frames includes the tire pressure monitoring information. A plurality of pause spaces is disposed between at least some of the frames in the burst. Characteristics of the frames in the burst may be selected based upon one or more of: government standards, industry requirements, receiver requirements, periodicity requirements, or power requirements. Other examples are possible. 
     The characteristics of the signal relate to at least one characteristic such as the total number of frames in the burst, the relative positioning of the frames within the burst, the number of frames in the burst from each of plurality of manufacturers, and the relative positioning of the frames within the burst wherein at least some of the frames are from different manufacturers. Other examples are possible. 
     The processor  810  is communicatively coupled to the sensor  802 , the transmitter  808 , the transmission buffer  804 , and the memory  806 . The processor  810  is configured to execute a control program stored in a memory and execution of the control program is effective to transmit the tire pressure information from the transmission buffer  804  to an external receiver via the transmitter  808  according to each of a plurality of communications formats incorporated into the control program and not according to a manufacturers&#39; code. 
     In other aspects, a receiver  820  is configured to receive the tire pressure information transmitted according to each of the plurality of communication protocols that is transmitted by the transmitter  808  at antenna  824  and communicate the information to processor  822  where the information can be processed. The receiver  820  is further configured to recognize the tire pressure information transmitted according to a selected one of the plurality of communication protocols and ignore the tire pressure information transmitted according to non-selected ones of the plurality of communication protocols. 
     Referring now to  FIG. 9 , one example of RF transmissions is described. In this example, a first burst  902  includes blocks (or frames)  904 ,  906 , and  908 . A second burst  920  includes frames  922 ,  924 , and  926 . Null frames  910  are inserted between the frames,  906 ,  908 ,  910 ,  922 ,  924 , and  926 . 
     Each of the blocks or frames  904 ,  906 ,  908 ,  922 ,  924 , and  926  includes tire pressure information. This information may be in the same or different formats. In one example, all frames  904 ,  906 ,  908 ,  922 ,  924 , and  926  include the information according to the protocol of a first manufacturer. In another example, frame  904  is in the protocol of a first manufacturer, frame  906  is according to the protocol of a second manufacturer, frame  908  is in the protocol of the first manufacturer, frame  922  is in the protocol of a third manufacturer, frame  924  is according to the protocol of a fourth manufacturer, and frame  926  is according to the protocol of a fifth manufacturer. In still another example, the frames are in the format of completely different manufacturers. In other aspects, a manufacturer may have different formats. For instance, a first manufacturer may have a first format and a second format. 
     In one aspect, once the burst is sent, it is repeatedly transmitted. The repetition is immediate and each new burst includes newly updated information transmitted in each frame of the burst. In another example, once the first burst  902  is sent and then a predetermined time later (e.g., 17 seconds) the second burst is sent. Then, the pattern is repeated. 
     In one aspect, the burst pattern cannot be changed by the user without the control program being entirely re-programmed. That is, a programming tool cannot be used to change the control program to transmit frames for additional/different manufacturers and cannot be used to select frames to transmit. 
     Referring now to  FIG. 10 , one example of protocol arrangement is described. As used herein, the term “protocol arrangement” refers to the arrangement of particular manufacturers&#39; frames within a burst so as to meet a predefined criteria. As shown in  FIG. 5 , the structure of six example bursts is shown. The frames are formatted according to the protocol of Manufacturer 1, with a first format (M1, F1); Manufacturer 1, with a second format (M1, F2); Manufacturer 1, with a third format (M1, F3); Manufacturer 2, with a single format (M2); Manufacturer 3, with a first format (M3, F1); Manufacturer 3, with a second format (M3, F2); Manufacturer 4, with a first format (M4, F1); and Manufacturer 4, with a second format (M4, F2). Pauses (P) are placed between the content-bearing frames. The length of each frame can vary. By “format”, it is meant the arrangement and contents of a frame such as the number of bits, the existence of certain fields, the arrangement of the fields, the existence of a checksum field, to mention a few examples. 
     It will be appreciated that various characteristics of the burst can be changed in the protocol arrangement. These characteristics can include the total number of frames in the burst, the relative positioning of the frames within the burst with respect to each other, the number of frames in the burst from each of plurality of manufacturers, the relative positioning of the frames within the burst where at least some of the frames are from different manufacturers, the frame that leads the burst, to mention a few examples. It will be appreciated that these characteristics can be adjusted based upon a variety of factors such as government standards, industry requirements, periodicity requirements, and power requirements of the transmitted signal and other system functional requirements. Other examples of characteristics and sources that affect/define these characteristics are possible. 
     It will be further understood that the particular factors used to select frames (i.e., that are transmitted according to a particular manufacturers&#39; protocol) can vary and that the exact selection varies depending upon the factors mentioned above. These factors can be adjusted to meet the needs of a particular user or system. It will be further appreciated that government and/or industry requirements can change over time, but the approaches herein can take into account any such changes, modifications, additions, or deletions to these requirements. 
     To take one example, the Federal Communications Commission (FCC) has a requirement that an on-the-air signal can not exceed one second. Further, the periodicity of a burst is also a FCC requirement and is required to be: P=on-the-air time*30, or 10 seconds, whichever is greatest. A manufacturer may have a periodicity requirement that a burst (or frame) be transmitted every 17 seconds (e.g., because of localization requirements of the manufacturer or so other requirement affecting periodicity). In this case, with P=17, the on-the-air time is approximately 500 ms. 
     Thus, transmissions can be made from each of the wheel units (four, one for each tire) as shown in  FIG. 11  with, for example, a duration of 500 ms. As shown, each wheel unit (monitor) sends a burst every 17 seconds. The first burst may be the first burst of  FIG. 10 , the second burst the second burst of  FIG. 10 , the third burst, the third burst of  FIG. 10 , and so forth (for simplicity, the third, fourth, fifth and sixth burst are not shown in  FIG. 10 ). 
     In other examples, the FCC has stated that for a particular frequency the average power cannot exceed 67.5 db uV/m at three meters. However, for small duration signals, this may be increased by 20 db to 87.5 db uV/m. To determine if a particular portion of a burst exceeds the maximum of 20 db (for a peak value), the base 10 log of (on-the-air time of a frame/100 ms)*20 is taken and this is referred to an averaging factor. Here, the on-the-air time is of the frame itself and does include pauses. For instance, for a frame having a duration of 10 ms, the average factor is 20 db. For a frame with a duration of 20 ms, the averaging factor is 10 db. Thus, in the later case, the averaging factor can be increased by 10 db, for example, by changing the frame to be that of a different manufacturer to increase the duration and the averaging factor. In this example, the frames within the burst are adjusted to obtain (or attempt to obtain) the maximum power at that portion of the burst. 
     In still other aspects, the number of frames of a particular manufacturer in a burst can be adjusted. For example, some manufacturers require that two or three frames of that manufacturer be transmitted in a burst. The number of frames of a particular manufacturer may also be adjusted depending upon whether the frames are transmitted according to FSK or ASK modulation. For instance, FSK is less susceptible to noise than ASK, so if the frames are ASK-transmitted, more of the ASK type frames may need to be transmitted. The order of frames within a burst can also be adjusted. For example, two frames from a single manufacturer may be transmitted with one frame at the beginning and the other in the middle or end of the burst to avoid noise problems since it is more likely that two frames placed together will be affected by noise rather than two frames spaced apart. 
     It should be understood that any of the devices described herein (e.g., the programming or activation devices, the tire pressure monitoring devices, the receivers, the transmitters, the sensors, the presentation devices, or the external devices) may use a computing device to implement various functionality and operation of these devices. In terms of hardware architecture, such a computing device can include but is not limited to a processor, a memory, and one or more input and/or output (I/O) device interface(s) that are communicatively coupled via a local interface. The local interface can include, for example but not limited to, one or more buses and/or other wired or wireless connections. The processor may be a hardware device for executing software, particularly software stored in memory. The processor can be a custom made or commercially available processor, a central processing unit (CPU), an auxiliary processor among several processors associated with the computing device, a semiconductor based microprocessor (in the form of a microchip or chip set) or generally any device for executing software instructions. 
     The memory devices described herein can include any one or combination of volatile memory elements (e.g., random access memory (RAM), such as dynamic RAM (DRAM), static RAM (SRAM), synchronous dynamic RAM (SDRAM), video RAM (VRAM), and so forth)) and/or nonvolatile memory elements (e.g., read only memory (ROM), hard drive, tape, CD-ROM, and so forth). Moreover, the memory may incorporate electronic, magnetic, optical, and/or other types of storage media. The memory can also have a distributed architecture, where various components are situated remotely from one another, but can be accessed by the processor. 
     The software in any of the memory devices described herein may include one or more separate programs, each of which includes an ordered listing of executable instructions for implementing the functions described herein. When constructed as a source program, the program is translated via a compiler, assembler, interpreter, or the like, which may or may not be included within the memory. 
     It will be appreciated that any of the approaches described herein can be implemented at least in part as computer instructions stored on a computer media (e.g., a computer memory as described above) and these instructions can be executed on a processing device such as a microprocessor. However, these approaches can be implemented as any combination of electronic hardware and/or software. 
     Those skilled in the art will recognize that a wide variety of modifications, alterations, and combinations can be made with respect to the above described embodiments without departing from the spirit and scope of the invention, and that such modifications, alterations, and combinations are to be viewed as being within the scope of the invention.