Information about the LOCO Track Primary HGD4 GPS tracker
| Component | Type | Note | Marking |
|---|---|---|---|
| nRF52840 | SoC | Main SoC, 1MB Flash, 256KB RAM | U1 |
| ESP8266 | WiFi SoC | 2MB external Flash, running AT firmware | IC8 |
| Quectel BG95-M3 | LTE Modem with GPS | USB exposed to debug pads | M1 |
| LIS3DH | Acceleration Sensor | Two units present | U2 |
| LIS3DH | Acceleration Sensor | Two units present | U3 |
| VEML6035 | Light Sensor | Next to push button, used for wake-up | IC7 |
| ENS210 | Temperature + Humidity Sensor | - | IC3 |
| TPL5010 | Watchdog | needs to be fed | IC4 |
| LPS22HB | Pressure Sensor | - | IC5 |
| Red LED | LED | - | LED1 |
| Green LED | LED | - | LED2 |
| Button | Push Button | Wakes the device power off | SW1 |
What we know about the pins of the nRF52840 so far:
| Pin | Description |
|---|---|
| 0 | !LED Green |
| 1 | !RED Green |
| 2 | VBAT measurement |
| 3 | NC |
| 4 | CS ACCL 2 |
| 5 | NC |
| 6 | CS ACCL 1 |
| 7 | NC |
| 8 | MISO |
| 9 | TPL5010 Wake input |
| 10 | TPL5010 Done output |
| 11 | Sensor VDD |
| 12 | SPI CLK |
| 13 | SCL |
| 14 | bridged to 16 and 18 |
| 15 | SDA |
| 16 | bridged to 14 and 18 |
| 17 | Modem Rxd GPIO |
| 18 | RESET |
| 19 | NC |
| 20 | connects to R29 R |
| 21 | NC |
| 22 | Modem Txd GPIO |
| 23 | NC |
| 24 | Connects to Q5 U R |
| 25 | NC |
| 26 | ACC U3 int |
| 27 | NC |
| 28 | NC |
| 29 | Modem + ESP power, switches the actual rail |
| 30 | NC |
| 31 | !Power Latch |
| 32 | Uart logging Rxd (broken out gpio) |
| 33 | Uart logging Txd (broken out gpio) |
| 34 | Modem !pwrkey |
| 35 | NC |
| 36 | VEML6035 INT |
| 37 | NC |
| 38 | Switch input |
| 39 | NC |
| 40 | NC |
| 41 | MOSI |
| 42 | Wifi Rxd Baud 115200 |
| 43 | Wifi Txd Baud 115200 |
| 44 | NC |
| 45 | ESP power pin |
| 46 | NC |
| 47 | ESP GPIO 0 |