Abstract:
A method and apparatus for powering a device, such as a data recorder or other device, according to an adjustable schedule. One example of the apparatus includes a programmable timer having an alarm output, a power regulator having an enable input coupled to the alarm output, a controller coupled to the power regulator and to the programmable timer, the controller being configured to receive operating power from the power regulator, and a powered device coupled to the power regulator and configured to receive power from the power regulator. The regulator has an operating state in which the operating power is provided to the powered device and an idle state in which the operating power is not provided to the powered device. The regulator is configured to be activated into the operating state by activation of the alarm output and deactivated into the idle state by deactivation of the alarm output, under the control of the controller.

Description:
BACKGROUND 
       [0001]    1. Field of Invention 
         [0002]    The present invention is directed to battery-operated, autonomous data recording devices, more particularly, to low power devices that can be configured to operate on a recording schedule. 
         [0003]    2. Discussion of Related Art 
         [0004]    There are many applications for automated data collection. In particular, the collection of audio data in the field can be used to monitor populations of wildlife such as birds, bats, frogs and whales for presence, absence, and abundance data for specific species. 
         [0005]    One of the greatest challenges in the deployment of data collection equipment in the field is the scarcity of power. Remote locations may not have access to power from utilities, and therefore, batteries are generally required to power data collection devices. Supplemental solar power may not be practical as solar systems tend to be heavy and expensive, and there may not be sufficient light in many installations. Weight can also be an important consideration for equipment that is moved from one remote location to the next, further limiting the size and capacity of batteries that can be used. Given the finite capacity of any battery power supply, the data recorder will only be able to operate for a limited period of time. The lower the amount of power consumed by the data recorder, the longer the recorder can operate and the more data can be collected before manual intervention (e.g. to replace batteries) is required. 
         [0006]    One approach to extending the operating life of automated data collection systems is to configure the systems to record on a schedule rather than continuously. In most cases, the power consumed for actual data recording is significantly greater than the power consumed to remain idle during scheduled down time. This approach is especially well suited to wildlife monitoring as different species are more likely to vocalize at certain times of day. For example, many species of birds sing at dawn while many species of frogs sing after dusk. 
         [0007]    However, conventional implementations of the above approach are not ideal as significant power is still consumed during the idle periods and the scheduling capabilities are limited. For example, referring to  FIG. 1 , there is illustrated an example of a conventional system discussed in an article entitled “The Use of Automated Data-Acquisition Techniques in Monitoring Amphibian and Reptile Populations,” by Charles R. Peterson and Michael E. Dorcas, Department of Biological Sciences, Idaho State University, and published on pages 369-378 in McCullough, D. R. and R. Barrett, 1992, Wildlife 2001: Populations, Elsevier Applied Science, London. According to the Peterson and Dorcas article, the system makes use of a series of interval timers  102  that trigger a relay  103  to power an off-the-shelf audio recorder  104 . Power is supplied by a battery  101 . One disadvantage of this system is that the relay  103  consumes extra power exceeding several milliwatts. Another disadvantage of this system is that the simple timers  102  provide limited programming flexibility. For example, the timers  102  are unable to accurately track the time of sunrise for given latitudes and times of year, to implement more complex sampling protocols, or to combine different protocols for the simultaneous monitoring of different species. 
         [0008]    Referring to  FIG. 2 , there is illustrated a block diagram of a subsequent version of the system of  FIG. 1 . The system of  FIG. 2  includes a microprocessor-based controller  202  to control power to the off-the-shelf audio recorder  104  using an efficient solid state power regulator  203 . While this approach improves the programming flexibility of the system, the microprocessor-based controller consumes several milliwatts of power, even when idle. 
         [0009]    In another implementation, an autonomous recording unit (developed by the Bioacoustics Research Program at the Cornell Lab of Ornithology) comprises an audio data recorder integrated with a controller by sharing a microprocessor. The microprocessor implements a recording schedule and directs the acquisition and storage of audio data. The integration of the data recorder and the controller represents an improvement of efficiency over the systems discussed above in reference to  FIGS. 1 and 2  by reducing the number of active components in the design. However, the microprocessor remains powered during idle periods and continues to consume power. 
       SUMMARY 
       [0010]    Aspects and embodiments are directed to a system for scheduled autonomous data recording that uses almost no power when idle between scheduled recording periods. In one example, power consumption in the system may be reduced during data recording by combining redundant functional elements of the data recorder and the controller. In addition, the system may provide for highly flexible scheduling, as discussed further below. 
         [0011]    According to one embodiment, an apparatus for autonomous data recording comprises a timer with a data interface and an alarm output, a power regulator with an enable input activated by the alarm output, a controller powered by the output of the power regulator and interfacing to the timer using the data interface, and a data recorder powered by the output of the power regulator. In one example, the data recorder is an audio recorder. In another example, the controller may configure the timer to deactivate the alarm output for a period of time causing the regulator to be disabled and power to be disconnected from the controller until the time period elapses. The apparatus may further comprise a switch to manually override the enable input to the regulator. In another example, the controller comprises a microprocessor, and the timer and power regulator are integrated with the microprocessor such that idle portions of the microprocessor are powered down during idle periods. Optionally, the data recorder and the controller can share a microprocessor. 
         [0012]    According to another embodiment, an apparatus for autonomous data recording comprises a programmable timer having a programming interface and an alarm output, a power regulator having an enable input coupled to the alarm output, a power input and a power output, a power source coupled to the power input of the regulator, a controller coupled to the power output of the power regulator and to the programming interface of the programmable timer, and a data recorder coupled to the power output of the power regulator. The power regulator has an operating state in which power is provided at the power output and an idle state. The power regulator is activated into the operating state by activation of the alarm output and deactivated into the idle state by deactivation of the alarm output. In one example, the data recorder is an audio recorder. In another example, the controller is configured to program the programmable timer, via the programming interface, to deactivate the alarm signal for a predetermined period of time. The apparatus may further comprise a switch coupled between the power regulator and the programmable timer, the switch having an ON position and an OFF position and being configured to activate the enable input of the regulator when in the ON position. In another example, the controller comprises a microprocessor. Optionally, the microprocessor may be shared between the controller and the data recorder. In another example, the controller comprises a first oscillator having a first operating frequency, and the timer comprises a second oscillator having a second operating frequency. The first operating frequency is higher than the second operating frequency. The programmable timer may be a single stage timer or a multi-stage timer. In one example where the timer is a multi-stage timer, the controller is configured to program the multi-stage timer to implement a multi-stage timing schedule including a first stage in which the controller is configured to program the programmable timer, via the programming interface, to deactivate the alarm signal for a first predetermined period of time, and a second stage in which the controller is configured to program the programmable timer, via the programming interface, to deactivate the alarm signal for a second predetermined period of time. 
         [0013]    Another embodiment is directed to a method of controlling a data recorder including a controller, a power regulator and a timer. The method comprises programming the timer to activate the power regulator for a predetermined recording time period, providing power from the power regulator to the controller during the predetermined recording time period, and powering down the controller when the predetermined recording time period expires by deactivating the power regulator. In one example, programming the timer includes programming the timer with the controller. In another example, the method further comprises providing power from the power regulator to a recording device during the predetermined recording time period. The method may further comprise recording data with the recording device during the predetermined recording time period. 
         [0014]    According to another embodiment, an apparatus comprises a programmable timer having a programming interface and an alarm output, a power regulator having an enable input coupled to the alarm output, a power input and a power output, a power source coupled to the power input of the regulator, a controller coupled to the power output of the power regulator and to the programming interface of the programmable timer, the controller being configured to receive operating power from the power regulator, and a powered device coupled to the power output of the power regulator and configured to receive power from the power regulator. The regulator has an operating state in which the operating power is provided at the power output and an idle state in which the operating power is not provided at the power output, and is activated into the operating state by activation of the alarm output and deactivated into the idle state by deactivation of the alarm output. The controller is configured to program the programmable timer, via the programming interface, to deactivate the alarm signal for a predetermined period of time. 
         [0015]    Another embodiment is directed to a method of powering a device including a controller, a power regulator and a timer. The method comprises programming the timer with the controller to activate the power regulator for a predetermined active time period, providing power from the power regulator to the controller during the predetermined active time period, providing power from the power regulator to the device during the predetermined active time period, and powering down the controller and the device when the predetermined active time period expires by deactivating the power regulator. In one example, providing power from the power regulator to the device includes providing power to a data recorder during the predetermined active time period. In another example, the method further comprises recording data with the data recorder during the predetermined active time period to provide recorded data. The method may also comprise analyzing the recorded data to determine information, and adjusting at least one of a duration and a start time of the predetermined active time period responsive to the information. 
         [0016]    Still other aspects, embodiments, and advantages of these exemplary aspects and embodiments, are discussed in detail below. Moreover, it is to be understood that both the foregoing information and the following detailed description are merely illustrative examples of various aspects and embodiments, and are intended to provide an overview or framework for understanding the nature and character of the claimed aspects and embodiments. The accompanying drawings are included to provide illustration and a further understanding of the various aspects and embodiments, and are incorporated in and constitute a part of this specification. The drawings, together with the remainder of the specification, serve to explain principles and operations of the described and claimed aspects and embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    Aspects and embodiments of the invention are described in detail below with reference to the accompanying drawings. It is to be appreciated that the drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings: 
           [0018]      FIG. 1  is a block diagram of one example of a conventional data collection device; 
           [0019]      FIG. 2  is a block diagram of another example of a conventional data collection device; 
           [0020]      FIG. 3  is a diagram of one embodiment of a data collection device, according to aspects of the invention; and 
           [0021]      FIG. 4  is a diagram of another embodiment of data collection device including an integrated controller and data recorder, according to aspects of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Aspects and embodiments of the present invention are directed to a data collection device, and make use of a low-power programmable digital timer configured to enable power supply to the remaining components in the system. The data collection device operates on a schedule, having active periods (during which the device is recording) and idle periods during which a majority of the device components may be powered down. According to one embodiment, during idle periods, the power supply control circuit and the programmable digital timer are the only portions of the system consuming power, as discussed further below. Using commercially available timers (such as real-time clock integrated circuits) and power regulators, the amount of idle power consumed may be generally only a few microwatts. In addition, in one embodiment, a microprocessor-based controller is used to implement a highly flexible recording schedule, as discussed further below. 
         [0023]    Unlike conventional systems, the controller in system according to embodiments of the invention may be powered only during scheduled recording periods and during initial programming of the schedule or other maintenance operations. The controller, in turn, may program the digital timer to disconnect its own power until the next scheduled event occurs, as discussed further below. A manual switch may be provided to override the digital timer and force power to the controller for initial programming of the schedule or other maintenance operations. In addition, the same controller may also acquire and store data, rather than making use of a separate microprocessor-based data acquisition system, to eliminate the duplication of active components such as microprocessors, computer memories and other peripherals. 
         [0024]    It is to be appreciated that this invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of implementation in other embodiments and of being practiced or of being carried out in various ways. Examples of specific implementations are provided herein for illustrative purposes only and are not intended to be limiting. In particular, acts, elements and features discussed in connection with any one or more embodiments are not intended to be excluded from a similar role in any other embodiments. In addition, it is to be appreciated that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use herein of “including,” “comprising,” “having,” “containing,” “involving,” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. 
         [0025]    Referring to  FIG. 3 , there is illustrated a block diagram of one example of a data collection device according to aspects of the invention. In the illustrated embodiment, a battery  301  provides power to a programmable digital timer  302  and a power regulator  303 . The power regulator  303  has an enable signal  308  to enable or disable the flow of current to a microprocessor-based controller  304  and to a data recorder  305 . The enable signal  308  for the regulator  303  may be generated by either the timer  302  or a manual switch  307 , as discussed further below. It is to be appreciated that in some embodiments, the apparatus (including the controller  304 , timer  302  and power regulator  303 ) may also be used to controllably power a device other than a data recorder. 
         [0026]    The timer  302  may be very simple low-power device, such as a simple up or down counter with a comparator, or a real-time clock integrated circuit chip. There are commercially available real-time clock chips that consume only a few microwatts of power and that are capable of generating an alarm signal at a particular date and time. One embodiment of the data collection system incorporates such a real-time clock chip as the timer  302 , and the alarm signal from the timer can be used as the enable signal  308  to the regulator  303 . Additionally, according to one embodiment, the timer  302  has a digital data interface  306  such as SPI or I 2 C, such that it can be programmed by the controller  304  (e.g., using a microprocessor included in the controller). For example, the controller  304  may read or set the current time, turn on or off the alarm signal, or set the time of the next alarm. 
         [0027]    As discussed above, in one example, the switch  307  may be configured to manually override the enable signal  308  such that an operator can force the regulator  303  to provide power to the controller  304  for initial programming, configuration and maintenance. The switch  307  may be implemented as a button, “flip switch,” lever, or any other device that can be activated by an operator. Once powered up, the controller  304  may program the timer  302  to activate the enable signal  308  so that the switch  307  no longer needs to be on to keep the controller powered up. In  FIG. 3 , the switch  307  is shown connecting an active-low enable signal ( 308 ) to ground, and a typical implementation may also employ a pull-up resistor (not shown) on the enable signal ( 308 ). However, it is to be appreciated that the invention is not limited to implementation illustrated in  FIG. 3 , and an equivalent circuit may be implemented for an active-high enable signal. 
         [0028]    Still referring to  FIG. 3 , in one embodiment, the controller  304  can optionally control the data recorder  305 , for example, to start and stop data collection. According to one embodiment, the controller  304  may program the timer  302  with a predetermined schedule, for example, to activate the enable signal  308  at specified time intervals (e.g., every two or three hours), or every day at some specified time (e.g., dawn or dusk), and to keep the enable signal activated for a specified time (e.g., one hour). It is to be appreciated that the controller  304  may also program (or re-program) the timer  302  between recording events so as to implement an arbitrary recording schedule. In one example, after finishing a scheduled recording, the controller  304  may program the timer  302  to release the enable signal  308  until the next scheduled recording time, thereby powering down the power regulator  302  and components (including the controller itself) coupled thereto. 
         [0029]    As discussed above, the controller  304  may program or re-program the timer  302  at any time when the controller is active, allowing for a highly flexible recording schedule to be implemented. In one example, the controller  304  can program the timer  302  with a predetermined schedule, as discussed above. In this example, there may be no need for the controller  304  to reprogram the timer  302  every time the controller is activated; however, the controller  304  may make adjustments to the schedule as needed or desired. For example, as discussed above, the controller  304  may program the timer  302  with a schedule that implements recording at a particular time of day (e.g., dawn, dusk, etc.). In this case (or similar instances), the controller may be programmed to account for seasonal changes in the times of dawn and dusk, and to reprogram the timer accordingly. The timer  302  may be a single-stage or multi-stage timer. Where the timer  302  is a multi-stage the timer, the controller  304  may program the timer with a schedule that varies by time period. For example, the controller  304  may program the timer  302  to record at a one time, or for one time period, on certain days of the week, and at another time, or for another time period, on other days of the week. Any of these schedules may be adjusted by the controller  304  whenever it is active, thus allowing for highly flexible timing. 
         [0030]    According to one embodiment, when the enable signal  308  is deactivated, power to the power regulator  302 , and therefore, also the controller  304  and data recorder  305 , is turned off. Thus, the power consumption during idle periods is minimized because only the timer  302  remains powered. Because the controller  304  programs the timer  302  to reactivate the enable signal at a specified time, there is no need for the controller to remain active during the idle period. This ability to implement highly flexible, even arbitrary, timing while also enabling the controller, which controls the timing, to be powered down during idle periods may be a significant improvement over conventional systems in which a controller remains powered during idle periods. 
         [0031]    According to one embodiment, the data recorder  305  will include data acquisition hardware such as sensors, amplifiers, filters, and analog-to-digital converters. The data recorder may also include a microprocessor to read samples from the data acquisition hardware, a storage device to format and store the acquired data, such as a disk drive, flash memory or magnetic media, and computer memory for storing microprocessor instructions. In some examples, the controller  304  will also include a microprocessor and computer memory. Therefore, according to one embodiment, power consumption can be further reduced by combining these common elements from the controller  304  and data recorder  305  into one integrated system. 
         [0032]    Referring to  FIG. 4 , there is illustrated one example of a system including an integrated controller and data recorder, according to aspects of the invention. As shown in  FIG. 4 , the enable signal  308  from the power regulator  303  is used to enable or disable the flow of current to the integrated controller and data recorder  401 , and operation of the system illustrated in  FIG. 4  is similar to operation of the system illustrated in  FIG. 3 . 
         [0033]    As discussed above, the controller  304  may have the ability to arbitrarily reprogram the timer  302  at any time when the controller is active, thus implementing dynamic, flexible timing or scheduling. In one example, the controller  304  may apply a sampling heuristic to a recording schedule. For example, the microprocessor may analyze recorded data to determine the location within a recording time period of a peak in target data. For example, if an operator hopes to determine or monitor the presence of a particular bird, or other animal, the microprocessor may analyze the recorded data to detect a peak in the data corresponding to sounds made by that bird (e.g., the bird may be most vocal shortly after dawn). The controller  304  may then program the timer  302  to implement a recording window around the time of the detected peak. The microprocessor may repeatedly analyze data after each (or some specified number of) recording time period and signal the controller  304  to reprogram the timer  302  as needed to adjust the recording window to track movements of the peak in the target data. In this manner, the controller  304  may adjust the timing schedule responsive to the recorded data. It is to be appreciated that although this example has been explained in terms of monitoring the sound of a bird, the invention is not so limited, and the controller  304  may implement a sampling heuristic based on any type of recorded data. 
         [0034]    Referring again to  FIGS. 3 and 4 , it is to be appreciated that the regulator  303  may be replaced with any solid state power switch such as a transistor. Alternatively, the regulator  303  may be replaced with a relay. However, relays are less efficient and therefore, may not be presently preferred in some applications. Additionally, the regulator  303  may include several individual regulators providing power to different portions of the controller  304 , data recorder  305 , or integrated controller and data recorder  401 . It is further to be appreciated that the microprocessor used in any of the controller  304 , data recorder  305 , or integrated controller and data recorder  401  may take many forms including a microcontroller or a digital signal processor with integrated peripherals. In addition, it is to be appreciated that at least parts of the power regulator  303  and/or digital data interface  306  may be integrated with the microprocessor, such that most of the system can be powered down while the timer  302  continues to run. In one such example, the timer  302  or manual switch  307  can be configured to cause an interrupt resulting in power to the microprocessor being restored. 
         [0035]    According to one embodiment, the timer  302  may include an oscillator circuit to provide a periodic clock signal for keeping time and scheduling. The controller  304  and/or the data recorder  305  (or the integrated controller and data recorder  401 ) may also require one or more periodic clock signals to provide timing to a microprocessor. In many cases, the desired clock frequency for microprocessors and data acquisition systems may be substantially higher than the clock frequency required for the timer  302  used for scheduling. For example, the controller and/or data recorder may use a 24 MHz oscillator and the timer  302  may use a 32 KHz oscillator. In one embodiment, the controller and/or data recorder may be configured to allow real-time streaming of quality audio to be formatted and stored on the storage media of the data recorder using a 24 MHz oscillator, which is a substantially lower frequency oscillator than what might be used in conventional systems (which use, for example, 200 MHz or higher oscillators). Higher frequency oscillators generally consume more power than low frequency oscillators. Therefore, configuring the controller and/or data recorder to operate using a relatively low frequency oscillator may provide significant power savings. 
         [0036]    In addition, in one presently preferred embodiment, the system may employ different oscillators to provide clock signals to timer  302  and to the controller  304  and/or data recorder  305  or the integrated controller and data recorder  401 . As discussed above, even though the controller and/or data recorder may be configured to use a lower frequency oscillator than conventional systems, the timer  302  may run on an even lower frequency oscillator. Thus, by using different oscillators for different parts of the system, the higher frequency oscillators used for the controller and/or data recorder may be powered down during idle periods of the system, while a lower frequency oscillator used for the timer  302  continues to run. In this manner, additional power savings may be achieved during the idle periods as only a very low frequency (e.g., about 32.768 KHz compared to several MHz or hundreds of MHz), and thus very low power, oscillator may run during the idle periods. By contrast, idling a microprocessor, as is done in conventional systems (particularly those that use a microprocessor-based timer to control scheduling, such as the system of  FIG. 2  discussed above) still consumes relatively high power because a fast oscillator must be powered during the idle periods. 
         [0037]    Thus, aspects and embodiments of the invention may provide an efficient, low-power, highly flexible data recording system. By using a programmable timer  302  and separate oscillators for different parts of the system, a flexible recording schedule may be implemented in a system that is power-efficient because higher power components (including those that use faster oscillators) can be powered down during idle (non-recording) periods. 
         [0038]    Having thus described several aspects of at least one embodiment, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. For example, the data recorder  305  may be replaced by another device that receives power from the power regulator. Such alterations, modifications, and improvements are intended to be part of this disclosure and are intended to be within the scope of the invention. Accordingly, the foregoing description and drawings are by way of example only, and the scope of the invention should be determined from proper construction of the appended claims, and their equivalents.