Abstract:
A method of reprogramming a flash memory of a liquid crystal display (LCD) in a presentation device can include using an external electronic diagnostic tool and a controller area network (CAN) diagnostic interface within the device to initiate data transfer. Data can be transmitted to an LCD microcontroller within the device using a high speed infrared link between the diagnostic tool and microcontroller. The data can be stored in a memory within the device in bi-directional communication with the microcontroller. Proper reception by the microcontroller of the infrared transmitted data can be verified by the diagnostic tool and the CAN diagnostic interface. A command can be issued from the diagnostic tool directing how to employ the data to reprogram the LCD.

Description:
FIELD 
     The present disclosure relates to instrument clusters and more particularly to an instrument cluster and method for wirelessly communicating data from a diagnostic tool to the instrument cluster or any vehicle system visible by the user. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     Automotive instrument clusters typically comprise large discreet display areas for a speedometer, a tachometer, and a number of smaller displays for coolant temperature, oil pressure, oil temperature, fuel level and the like. Arranged within and around the cluster are other indicators showing low fluid level conditions, turn signal operation, emergency light blinkers and so forth. In a conventional display, a rotating analog needle or pointer is provided for sweeping across a range of values to indicate a measured quantity. In other examples, a light beam can be used to scan across a similar range of values. Other configurations include digital displays that are operable to simply display a numerical value associated with a given unit of measurement. 
     In some instances, these instrument clusters may need to be reprogrammed, such as when a software update is needed. Generally, reprogramming can occur over the general controller area network (CAN) bus using an onboard module in the vehicle that acts as a diagnostic gateway. In many instances, a diagnostic connector in the foot well of the driver&#39;s side of the vehicle can be accessed by connecting a wired link from a handheld electronic device. This diagnostic connector provides a communication link that is generally optimized for response time and is not ideal for large file transfer speed. For example, in many instances, the top speed of the CAN by way of the wired diagnostic connector can be about 500 kilobytes per second. In real use, however, it is typical to only utilize 60% for data transfer, which leaves about 300 kilobits per second as a maximum data rate of transfer. This can be reduced further by the multiple connected modules. 
     Instrument clusters have been evolving recently to incorporate thin film transistor liquid crystal displays (TFT-LCD). The TFT-LCD&#39;s can be configured to display any information, such as information associated with any of the gauges and indicators listed above and/or information related to various components of the vehicle, such as the engine, transmission, fuel system and the like. As can be appreciated, the TFT-LCD&#39;s graphics can require an increased amount of stored data for operation. For example, some TFT-LCD displays can utilize between eight and sixteen megabytes of storage. With the conventional CAN bus update method utilizing the diagnostic connector described above, a reprogramming event can take over one hour per cluster. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
     A method of reprogramming a flash memory of a liquid crystal display (LCD) in a presentation device can include using an external electronic diagnostic tool and a controller area network (CAN) diagnostic interface within the device to initiate data transfer. Data can be transmitted to an LCD microcontroller within the device using a high speed infrared link between the diagnostic tool and microcontroller. The data can be stored in a memory within the device in bi-directional communication with the microcontroller. Proper reception by the microcontroller of the infrared transmitted data can be verified by the diagnostic tool and the CAN diagnostic interface or the infrared link if bi-directional. A command can be issued from the diagnostic tool directing how to employ the data to reprogram the LCD. 
     According to additional features, the data can be transmitted through an infrared (IR) signal between the diagnostic tool and the microcontroller. Using the external electronic diagnostic tool can include locating the diagnostic tool proximate to a CAN diagnostic interface. Using the CAN diagnostic interface can include using a destination infrared (IR) receiver provided on the presentation device to receive the transmitted data through the high speed infrared link. In one example, the destination IR receiver includes a universal asynchronous receiver transmitter (UART). According to one implementation, transmitting the data can include transmitting the data from the external electronic diagnostic tool through a source infrared (IR) transmitter provided on the external electronic diagnostic tool. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
         FIG. 1  is a front view of an instrument cluster having a TFT-LCD and infrared (IR) transmitter/receiver according to one example of the present teachings and shown associated with an exemplary external electronic diagnostic tool; 
         FIG. 2  is a cross-sectional view taken along lines  2 - 2  of the instrument cluster shown in  FIG. 1 ; 
         FIG. 3  is an exemplary schematic view of a main micro-controller, a display micro-controller, the TFT-LCD display and the external electronic diagnostic tool according to one example of the present teachings; and 
         FIG. 4  is an exemplary method of reprogramming the TFT-LCD display in the instrument cluster according to one example of the present teachings. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
     With initial reference to  FIG. 1 , a presentation device in the form of an instrument cluster constructed in accordance with one example of the present teachings is shown and generally identified at reference numeral  10 . The instrument cluster  10  can have a fascia  12  including a display  14 . The display  14  can comprise a plurality of gauges  16   a - 16   d  for displaying measured quantities. In one example, the gauges  16   a - 16   d  can be formed in an appliqué  18 . The appliqué  18  in the embodiment shown may be taken to be representative of a speedometer display (gauge  16   a ) for displaying vehicle speed, a tachometer display (gauge  16   b ) for displaying engine speed, a fuel level display (gauge  16   c ) for displaying a fuel level, and an engine temperature display (gauge  16   d ) for displaying an engine temperature. 
     While the gauges  16   a - 16   d  have been specifically described as being a designed for display of a specific measured quantity, any of the gauges  16   a - 16   d  can be configured to represent other measured quantities, such as, but not limited to, a coolant temperature, an oil pressure, a cabin temperature, an outside temperature, and the like. Furthermore, the gauge locations of any of the gauges  16   a - 16   d  are interchangeable. Moreover, one or more of the gauges  16   a - 16   d  may be eliminated or more gauges may be added without departing from the scope of the present disclosure. 
     Various non-analog displays or “tell-tales” collectively referred to at reference numeral  20  can include a check engine display  22 , an airbag display  24 , a safety restraint display  26 , a traction control display  28  and a tire pressure display  30 . Other tell-tales may also be provided. 
     The instrument cluster  10  can further include a TFT-LCD  34  and a destination infrared transmitter/receiver  36 . The TFT-LCD  34  can be configured to display any information, such as any measured quantity described above associated with the gauges  16   a - 16   d , and/or any of the display information associated with the tell-tales  20 . The TFT-LCD  34  can additionally or alternatively be configured to display information associated with a trip computer, a navigation system, a vehicle entertainment system, or any other information that may be useful for the vehicle operator. As will be described in greater detail herein, the destination IR transmitter/receiver  36  can be in the form of a universal asynchronous receiver transmitter (UART). 
     As illustrated in  FIG. 2 , the instrument cluster  10  can include a housing  38  that has an overhang  37  and a transparent pane  39 . The overhang  37  can provide a partial shield or barrier for shading sunlight and/or ambient light from the destination IR transmitter/receiver  36 . The overhang  37  can help minimize interference from sunlight and/or ambient light near the destination IR transmitter/receiver  36 , such as during a data transmitting event as will be described. It will be appreciated that the destination IR transmitter/receiver can be located elsewhere in the instrument cluster  10 , such as closer to the overhang  37 . 
     With continued reference to  FIG. 1 , an external electronic diagnostic tool  40  is shown. The external electronic diagnostic tool  40  can have a user interface  42 , a display  44 , a source IR transmitter/receiver  46  and a controller area network (CAN) diagnostic interface  48 . The external electronic diagnostic tool  40  is operable in one configuration to transmit an IR signal  50  from the source IR transmitter/receiver  46  that can be received by the destination IR transmitter/receiver  36  in the instrument cluster  10 . According to one example, an infrared link can be provided between the destination IR transmitter/receiver  36  and the source IR transmitter/receiver  46  for communicating data through a contact-less high speed communication link. The destination IR transmitter/receiver  36  can respond via a main microcontroller  54  via the CAN diagnostic interface  48 . 
     The data received by the destination IR transmitter/receiver  36  can be communicated between the main micro-controller  54  and/or a display micro-controller  56  by way of a serial peripheral interface. The main micro-controller  54  can communicate signals between various modules of the vehicle (i.e. such as related to an engine, transmission, body control, etc.). The display micro-controller  56  can communicate signals to the TFT-LCD  34 . In one example, the external electronic diagnostic tool  40  can provide a UART signal that may be converted to an IR output (i.e., the IR signal  50 ). The IR signal can be a high speed IR signal that communicates up to or more than 125 kilobytes per second. 
     This IR signal  50  received by the destination IR transmitter/receiver  36  can then be converted by a photo detector (such as a photo transistor or a photo diode) back to a logic level signal for use by receiving circuitry associated with the instrument cluster  10 , such as the main micro-controller  54  and/or the display micro-controller  56  (see  FIG. 3 ). The receiving circuitry provides a physical interface to the IR signal. Additionally, it can perform message verification, check sum, buffering and handles the flash programming. The infrared link can be bi-directional by placing a transmitter/receiver pair on both of the source object (the external electronic diagnostic tool  40 ) and the destination object (the destination IR transmitter/receiver  36 ). In another example, such as when the infrared link is uni-directional, a wired CAN connection  60  (illustrated in phantom) can be provided between external electronic diagnostic tool  40  and the instrument cluster  10 . 
     The infrared link provided by the combination source and destination IR transmitter/receiver  46 ,  36  through the IR signal  50  provides a high speed, low cost configuration for communicating data to an internal flash  62 ,  FIG. 3 , such as during a software update. This results in the ability to reduce reprogramming time by a factor of about 50 or more over current conventional methods, such as by using a wired connection through a diagnostic connector described above. 
     Turning now to  FIG. 4 , an exemplary method of reprogramming the flash  62  of the instrument cluster  10  using the external electronic diagnostic tool  40  is shown and generally identified at reference numeral  70 . At the outset, an updated data file is acquired or transferred onto the external electronic diagnostic tool  40  in step  72 . It is appreciated that the updated data file can be created remotely and subsequently transferred onto the external electronic diagnostic tool  40 . In other examples, the external electronic diagnostic tool  40  can be used to create the updated data file, such as by using the user interface  42 . 
     In step  72 , the external electronic diagnostic tool  40  is located in proximity with the destination IR transmitter/receiver  36 . In step  76 , the updated data file is transmitted through the IR signal  50  from the source IR transmitter/receiver  46  on the external electronic diagnostic tool  40  to the destination IR transmitter/receiver  36  provided on the instrument cluster  10 . In step  78 , the updated data file is then stored in the display micro-controller  56 , such as in a random access module (RAM)  64 . In some examples, the updated data file can additionally or alternatively be stored for use by the main micro-controller  54 . In step  80 , the external electronic diagnostic tool  40  can be used to verify reception of the updated data file by the display micro-controller  56 . In step  82 , the external electronic diagnostic tool  40  can be used to direct implementation of the updated data file to reprogram the flash  62 . Additionally, steps  78  and  82  can occur multiple times in a block transfer manner, such as 5% at a time. 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.