Here is a face plate from my Kenwood KDC-MP6090R CD/MP3 car audio system I bought in 2002. Unfortunately the head unit was stolen, and the face plate was left in my drawer for some years. Then one day I thought about maybe I could connect to it and play with LCD just for fun. After disassembling it and searching internet for datasheets I wrote demo program.
It has Sanyo LC75808 LCD display driver (1/8 duty) and uses Sanyo CCB protocol.
|Pin number||Pin name||Description||HY-STM32 board|
|2||ILL+B||+10.7V for LED illumination||12V from external power supply|
|4||L CLK||Serial clock||PB13|
|5||L CE||Chip enable||PB12|
|6||RESET||Reset (active low)||PC10|
|7||L DATAS||Serial data input||PB15|
|8||L DATAL||Serial data output||PB14|
|9||DIMMER||Dimmer (active low)||PD4|
|11||REMO||Remote infrared connection||PD12|
- 12 symbols, each symbol is 7 pixels high and 5 pixels wide.
- There is no font, each pixel is separately addressable.
- 56 special symbols.
- 20 keys.
- Sending : send 72 bytes with display and control data.
- Receiving: send 1 byte and read 4 bytes with key data.
- +12V for LED illumination is OK.
- 3.3V for VDD is OK.
The IDE ribbon cable matched the connector perfectly. I soldered one end of the cable to face plate and used 14 pin IDC connector on the other end. Also drilled two holes and fastened the cable with metal plate with two bolts.
I wrote font and library with following functions:
- Sending data.
- Receiving data.
- Display character at any position.
- Display text at any position.
- Scroll text up/down/left/right.
- Turn special symbols on/off.
- Display digits from 0 to 9 at “ch” position.
- Set LED illumination green/red/off.
- Dimmer on/off.
- Set LCD contrast.
I setup demo with 12V power supply for LED illumination, breadboard for common ground connections and STM32F103VET6 microcontroller development board.
The demo displays text “Hello world!”.
- Pressing blue button “Q” displays text “Hello world!”.
- Pressing button “ATT” displays text “Attention”.
- Buttons “Volume up/down” scrolls text left/right by symbol (5 pixels).
- Buttons “Seek left/right, FM,AM” scrolls text left/right/up/down by pixel (1 pixel).
- Buttons “1/2” increases/decreases contrast.
- Buttons “3/4/5” makes LED illumination red/green/off.
- Button “6” toggles dimmer.
- Button “SRC” toggles displaying of digit at “ch” position.
- Buttons “-/eject” increments/decrements digit at “ch” position.
- Each press of button “TI” displays next special symbol.
- Button DISP” toggles displaying of all special symbols.
- Button “Play” clears/fills all pixels of LCD.
The source code of Kenwood_KDC-MP6090R demo is available at github.com: Kenwood_KDC-MP6090R.