This project aims to develop an open-source smartwatch design based around an ESP32-S3 microcontroller, as it offers many useful features, such as integrated Wi-Fi, Bluetooth and 8MB of PSRAM. This allows a watch to be designed with a minimal number of extra components beside the MCU itself.
| Component | Model | Datasheet |
|---|---|---|
| MCU | ESP32-S3R8 | ESP32-S3 |
| Display | CFAF240240A3-013TN | CFAF240240A3-013TN |
| Barometric Pressure Sensor | BMP390 | BMP390 |
| IMU | ICM-42688-P | ICM-42688-P |
| GNSS Receiver | MIA-M10Q-0 | MIA-M10Q |
| Flash | IS25LP128F-JKLE (16MB) | IS25WP128 |
| Battery Charger | BQ24075RGTR | BQ24075 |
| Fuel Gauge | BQ27441DRZR-G1A | BQ27441-G1 |
| Battery | ASR00007 | ASR00007 |
| Battery Connector | SM02B-SRSS-TB(LF)(SN) | SM02B-SRSS-TB(LF)(SN) |
| Main SMPS | TPS631000DRLR | TPS631000 |
| LED Driver | AP3036B | AP3036B |
| GPIO | Function |
|---|---|
| 0 | Bootloader (Strapping) FREE |
| 1 | I2C SDA |
| 2 | I2C SCL |
| 3 | JTAG Source Select (Strapping) FREE |
| 4 | Power Switch |
| 5 | User Switch 1 |
| 6 | User Switch 2 |
| 7 | User Switch 3 |
| 8 | Input Current 1 |
| 9 | Input Current 2 |
| 10 | LCD CS |
| 11 | LCD MOSI |
| 12 | LCD SCK |
| 13 | IMU INT1 |
| 14 | IMU INT2 |
| 15 | 32KHz XTAL |
| 16 | 32KHz XTAL |
| 17 | GNSS RX (UART 1 TX) |
| 18 | GNSS TX (UART 1 RX) |
| 19 | USB- |
| 20 | USB+ |
| 21 | Fuel Gauge Interrupt |
| 26 | |
| ... | Flash / PSRAM |
| 37 | |
| 38 | GNSS TX Ready |
| 39 | GNSS Timepulse |
| 40 | LCD DC |
| 41 | LCD Backlight |
| 42 | LCD TE |
| 43 | UART 0 TX |
| 44 | UART 0 RX |
| 45 | Flash Voltage Select (Strapping) FREE |
| 46 | ROM Messages (Strapping) FREE |
| 47 | SMPS Mode |
| 48 | SMPS Enable |