• Porting our original indicator project to Atmel family controller and changing some of the fundemental operation of how the input is done and also making the display bi-color and in essence its 3 colors.
  The original design relied on too many connections between the controller and display it self, 12 for the display and 9 for selector for 6 speed manual transmission. The count would be less for say 5 speed or automatic transmissions.
  
  In this design, display had been separated onto its own pcb board which contains some logic chips to drive the LEDs and a processor board containing naturally the processor, voltage regulator and sensors/switches connections. Additionally inputs are triggered by grounding it rather then connecting to the matrix logic making it safer triggers and possibly avoiding damaging the processor or display or incorrect wiring
  
  
  Display
  Actual display due to complexity and to utilize available hardware is made of 2 boards soldered back to back   
  The LED board is made by us the bi-color 5x7 display configured as common cathode row is soldered on back of a custom shift register board controlling the matrix and which color is selected.  Due to sourcing issues of the surface mounted interconnecting connector there are 2 variations of the board. In majority the board remains same with exception of the connector of using either 5 pin HY or 2x3 PB connector linking it to the processor board via quasi SPI protocol.
  
  The shift register board was designed to friction fit opening thus it does not have any mounting holes other then surrounding 3 mm of PCB that a holding ring can fix it into place.
  
  The 74hc595 registers on the control board alone are responsible for decoding of which pixel is activated in the matrix. The as the data is being shifted out its selecting row on one register and column on second register with last 2 most significant bits controlling which color is selected by means of activating buffers on the 74hc244 driver.
  
  
  Assembly of the display board was designed to fit into our custom shift knobs. We will be producing boards with mounting holes in the future and on request.
  
  
  Processor board
  Build around ATmega4808, the board was build specifically for this purpose. As timing of the processor is not crucial  and with option of internal crystal that is very well trimmed and accurate, part count for the circuit is much simplified and compact. With 14 possible inputs SPI connector to the display and additional serial and I2C ports provided through additional PB connector. To help and power the board from 12V car power system, onboard 5v regulator produces stable supply to the processor and accompanying circuitry.
  For any one wishing to expand connection of the board into cars communication systems it can be interfaced via Single Wire low speed CAN or faster high speed CAN. However only one of the transceivers can be used at a time as they are sharing same CAN encoder.
  
  
   

  
  Software
  The decoded or shift register board is designed around 2 shift registers and 2 buffers enabling respective colors. So basically whats needed is a scanner of rows and colums. One register controls which row is active and the other register controls which dots in the row to turn on and which color to enable.
  
  A sample pattern  for letter 'N' is below. With MSB on left controlling the color buffers and bit 6 & 7 high turn on both buffers thus mixing colors resulting in purple from red & blue combination
  
  This is a pattern of N
  B01x10001, // Row 1: * *
  B01x11001, // Row 2: ** *
  B01x10101, // Row 3: * * *
  B01x10011, // Row 4: * **
  B01x10001, // Row 5: * *
  B01x10001, // Row 6: * *   x
  B01x10001 // Row 7: * *
  
  The provided sample code writen for manual transmission and as it would be hard to sense neutral position, we are defaulting N when nothing is sensed. This way we will have N when in neutral and in between switching gears. When any other gear is selected respective pattern will be selected and sent to the display. 
  The program can be very easily adapted to automatic transmission just by switching character pattern.
  
  The code however is not suitable for sequential transmissions like you find it in motorbikes. as you would need to keep track which gear the bike is in and change based on shift.
  
  
  
  Features

     3 color mixing
     lower wire count interconnection between processor and display
     safer trigger inputs by utilizing hall effect sensors
     processor board features Single wire GMLAN 33.3Kb or flex CAN drivers
     fast ATmega4808 processor  
    
   

  Documents

     Schematics
        LED

        Shift register board
        Processor board

     PCB layout
     Bill of Materials
     Sample program  ATmega328P no CAN implementation
     Processor board  3d STL files