A Raspberry Pi 4 add-on board to protect and power the Pi from the v4 SR kit, and provide a visual indicator of the state of the brain board's software as detailed in the specification.
The UI is illustrated below.
The board was designed to be manufactured using JLCPCB for both the PCB and assembly. This is using as 2 layer board with single sided assembly. The two through-hole connectors are rear-mounted and manually added after.
The BOM and assembly files can be generated with KiCAD JLCPCB tools and the JLCPCB part codes are already assigned.
| Header Pin | GPIO | Function |
|---|---|---|
| 1 | - | - |
| 2 | - | 5V |
| 3 | - | - |
| 4 | - | 5V |
| 5 | - | - |
| 6 | - | GND |
| 7 | 4 | USER C Red LED |
| 8 | 14 | UART TX |
| 9 | - | GND |
| 10 | 15 | UART RX |
| 11 | 17 | USER C Blue LED |
| 12 | 18 | USER C Green LED |
| 13 | 27 | USER B Red LED |
| 14 | - | GND |
| 15 | 22 | USER B Blue LED |
| 16 | 23 | USER B Green LED |
| 17 | - | 3.3V |
| 18 | 24 | USER A Red LED |
| 19 | 10 | USER A Green LED |
| 20 | - | GND |
| 21 | 9 | Start LED |
| 22 | 25 | USER A Blue LED |
| 23 | 11 | Code LED |
| 24 | 8 | WiFi LED |
| 25 | - | GND |
| 26 | 7 | BOOT 20% LED |
| 27 | 0 | EEPROM SDA |
| 28 | 1 | EEPROM SCL |
| 29 | 5 | BOOT 40% LED |
| 30 | - | GND |
| 31 | 6 | BOOT 80% LED |
| 32 | 12 | BOOT 60% LED |
| 33 | 13 | BOOT 100% LED |
| 34 | - | GND |
| 35 | 19 | Heartbeat LED |
| 36 | 16 | Comp LED |
| 37 | 26 | Status Red LED |
| 38 | 20 | Status Green LED |
| 39 | - | GND |
| 40 | 21 | Status Blue LED |