This is just a way to document my findings regarding the board of my AJAZZ AK820PRO (BT/USB/2.4G 81 keys)
- map lcd module connections
- map status indicators' leds (Caps lock, Win lock)
- Mac/Win switch wiring
-
Main MCU - HFD80CP100 - appears to be based on/clone of SONIX SN32F99
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Bt module WCH CH582F
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External 16MB flash module PY25Q128HA
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LCD Module - 0.85" 128x128 NFP085B-10AF
| --- | col | C0 | C1 | C2 | C3 | C4 | C5 | C6 | C7 | C8 | C9 | C10 | C11 | C12 | C13 | C14 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| row | pin | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 29 | 30 | 27 |
| R0 | 38 | |||||||||||||||
| R1 | 39 | |||||||||||||||
| R2 | 40 | |||||||||||||||
| R3 | 41 | |||||||||||||||
| R4 | 42 | |||||||||||||||
| R5 | 43 |
| --- | r | b | g | col | C0 | C1 | C2 | C3 | C4 | C5 | C6 | C7 | C8 | C9 | C10 | C11 | C12 | C13 | C14 | C15 | C16 | C17 | C18 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| row | pin | pin | pin | pin | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 |
| R0 | 73 | 75 | 76 | 38 | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| R1 | 77 | 78 | 01 | 39 | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| R2 | 02 | 03 | 04 | 40 | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| R3 | 05 | 06 | 08 | 41 | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| R4 | 09 | 10 | 11 | 42 | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| R5 | 12 | 13 | 14 | 43 | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
Row RGB pins are connected to NPN transistors (C) - LED, (B) - GPIO, (E) - GND. Col RGB pin is connected to PNP transistor (E) - VDD, (B) - GPIO, (C) - LED +
- Bluetooth Mode: pin 36 (active high)
- 2.4 Ghz Mode: pin 37 (active high)
- Win - Android / Mac - iOS Mode: pin 70 (0-Win, 1-Mac)
- Caps Lock (White LED): pin 71/72/73
- Num Lock (White LED): pin 71/72/73
- Charging (RED LED): Charging (RED): ON, Charged:OFF
positive side of CAPS/WIN/CHARGING indicator goes to 1K resistors. The other side I couldn't trace. negative is common for all the 3 indicators and seems to be connected to MCU pins 71?/72/73 (??? This makes no sense to me)
| MCU | BT |
|---|---|
| 61 SCL0 | 10 - SCL |
| 60 SDA0 | 11 - SDA |
| ------- | 6 - RXD1 |
| ------- | 7 - TXD1 |
| ------- | 17- PB22/TMR3/RXD2 |
Near the BT module there are 10 pads (2x5) + 2 isolated rectangular pads. When looking at the CH582F chip upside down, the pins on the left are connected to the BT module like this (top to bottom):
1 - WCH Pin#10 - SCL 2 - WCH Pin#11 - SDA 3 - WCH Pin#6 - RXD1 4 - WCH Pin#7 - TXD1 5 - WCH Pin#17 - PB22/TMR3/RXD2
| MCU | Flash |
|---|---|
| 48 SEL1 | 1 CS# |
| 62 MISO1 | 2 SO |
| 71 P1.2 | 3 WP# |
| 4 GND | |
| 63 MOSI1 | 5 SI |
| 49 SCK1 | 6 SCLK |
| 57 VDDIO1 | 7 HOLD#RESET# |
| 8 VCC |
Found several reverences to 8 pin connectors of these boards with the following pin labels: VCC, GND, DIN (Serial data in), CLK (Serial clk in), ~CS(Chip select), DC (Data/~Command selection), RST (~Reset) and BL (Backlight). No way to read data from the LCD?
Possible LCD connector pinout (from similar devices found on Aliexpress with 8 pins):
| LCD pin# | Description |
|---|---|
| 1 | LED Anode |
| 2 | Power GND |
| 3 | RESET (active low) |
| 4 | Data/Command |
| 5 | SDA |
| 6 | SCL |
| 7 | VDD |
| 8 | CS (active low) |
| MCU | LCD Connector |
|---|---|
| 70 MISO0 0 | 1 |
| 79 VSS | 2 GND |
| ?? | 3 |
| ?? | 4 |
| 52 MOSI0 | 5 |
| 50 SCK0 | 6 CLK |
| 57 VDDIO1 | 7 |
| 59 SEL0 | 8 |
There are two pins under the SPACE bar. They are covered by 2 insulation layers and 1 removable foam strip (there are two strips on each side of the space switch that are easily removable). Cutting a window on the 2 insulation layers will give access to the pins. Shorting them while connecting the USB cable will make the MCU enter bootloader mode. In this mode the USB VID/PID will be 0x0C45/0x7140.
