Panasonic VP-0187A
==================
-It is unknown keyboard from Panasonic
+2017/08/06
-6P6C connector
+It is unknown keyboard from Panasonic with Hirose Cherry M8 and 6P6C connector.
-Hirose Cheery M8 switches
+Pictures:
+http://imgur.com/a/GAZE7
+
+Hirose Cheery M8 switches:
https://deskthority.net/wiki/Cherry_M8
||| |decoder|
||| ---------
||| |||||| col[0..7]
- ABC vvvvvvv pull down
+ ABC TC4512 vvvvvvv pull down
---------- <----|+++++++|--100K--+
|data | <----|+++++++|--100K--+
STATE<--|selector| <----|+++++++|--100K--+
| 7 to 1 | <----|+++++++|--100K--+
---------- <----|+++++++|--100K--+
- row[0..7] |
- 8x8 matrix -
- GND
+ row[0..7] | 8x8 matrix |
+ | -
+ TC4078 | GND
+ ------ |
+ SENSE<----| OR |========+ OR'd row[0..7]
+ ------
+- TC4520BP - Dual Binary Up Counter
+- TC4028B - BCD-to-Decimal Decoder
+- TC4512BP - 8-Channel Data Selector
+- TC4081BP - Quad 2-Input AND Gate
+- TC4071BP - Quad 2-Input OR Gate
+- TC4078BP - 8-Input NOR/OR Gate
Matrix
1. VCC
2. Clock - sends clock to binary counter TC4520
3. Key State - indicates hi if key selected by counter is active
-4. Sense - indicates hi if any key is active while Reset is hi.
+4. Sense - indicates lo if any key is active while Reset is hi.
5. Reset - resets counter and drives all column
6. GND
123456
,--------.
- | |
+ | |||||| |
| |
`--____--'
plug
+
+Ping configuration
+------------------
+AVR ATmega32u4 is used as protocol converter.
+
+ PD0: Clock. Counter couts up at falling edge.
+ PD1: Key State. Hi if selected key is activated.
+ PD2: Sense. Lo if any key is activated while Reset is Hi.
+ PD3: Reset. Resets counters at riging edge.