Panasonic VP-0187A
==================
2017/08/06
It is unknown keyboard from Panasonic with Hirose Cherry M8 and 6P6C connector.
Pictures:
http://imgur.com/a/GAZE7
Hirose Cheery M8 switches:
https://deskthority.net/wiki/Cherry_M8
Scan
----
The keyboard is comprised of some of 4000 series IC without microcontroller.
RST>-----------+---------------+
| |
TC4520 | TC4520 |
--------- carry ---------
CLK>--->|row |------>|col |
|counter|Q3 |counter|
--------- ---------
Q012 Q012
||| |||
||| ABC TC4028
||| ---------
||| |decoder|
||| ---------
||| |||||| col[0..7]
ABC TC4512 vvvvvvv pull down
---------- <----|+++++++|--100K--+
|data | <----|+++++++|--100K--+
STATE<--|selector| <----|+++++++|--100K--+
| 7 to 1 | <----|+++++++|--100K--+
---------- <----|+++++++|--100K--+
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
------
0 1 2 3 4 5 6 7
--------------------------------------------------------------------
0 ESC 1 2 3 4 5 6 7
1 8 9 0 - ^ BS INS DEL
2 TAB Q W E R T Y U
3 I O P @ [ ] F2 F1
4 CTRL A S D F G H J
5 K L ; : RETURN UP F3 F4
6 SHIFT Z X C V B N M
7 SPACE , . / LEFT RIGHT DOWN HOME
6P6C connector pinout
---------------------
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 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.
