Just an bluetooth audio board like the XY-BT-MINI, etc.
- SoC: AC6965A
On the board the pins are utilized as follows:
| Pin | Usage | Note |
|---|---|---|
| PB5 | Onboard LED | |
| PC5 | Mute | Driven high when no sound is playing |
| USBDM/PC3 | USB D- | Exposed on a pad on back side (next to VCC) |
| USBDP | USB D+ | Exposed on a pad on back side (next to GND) |
Extra functions that are available in the firmware my board shipped with:
| Pin | Usage | Note |
|---|---|---|
| PA0/PA2 | Mic bias | |
| PA1 (MIC) | Microphone | |
| PA3 | Line in L | |
| PA4 | Line in R | |
| PB4 | ? | |
| PB6 | Line in sense | Active low |
| PB7 | ? | |
| PC4 | ADKEY | Pulled up by an external 22k resistor on board |
ADkeys are as follows:
| Resistance | Key | < long press |
|---|---|---|
| 0R | Prev | Vol- |
| 3k | Play/Pause | Mode |
| 6k2 | Next | Vol+ |
| 9k1 | Mode | |
| 24k | Repeat | |
| 33k | EQ | |
| 51k | Vol+ | Vol+ |
| 100k | Vol- | Vol- |