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ToF Sensor VL53L1X

🔌 1. I2C Wiring (VL53L1X)

  • ESP32 I2C Pins:

    • SDA → GP5
    • SCL → GP4
ESP32 VL53L1X
GP5 SDA
GP4 SCL
3.3V VIN
GND GND

🧭 2. XSHUT (Sensor Power Sequencing)

The single sensor is enabled during boot through XSHUT.

ESP32 GPIO Sensor Connects to
GP6 Sensor 0 XSHUT pin

🛠️ 3. CAN Bus (TWAI on ESP32)

ESP32 TWAI uses dedicated GPIOs for CAN TX/RX.

ESP32 GPIO Connects to
GP9 CAN TX / TWAI TX (to transceiver)
GP10 CAN RX / TWAI RX (from transceiver)

💡 4. Status LED

One WS281x LED is connected to GP21 and uses FastLED at 50/255 brightness:

Distance LED behavior
0 mm Solid red (invalid/timeout reading)
1–50 mm Red blink at 50 Hz
51–999 mm Red blink rate scales linearly from 50 Hz down to 0 Hz
≥1000 mm Off

🔌 5. USB serial (ESP32-S3 Zero)

The sketch requires ESP32-S3 native USB CDC. In the Arduino IDE, select Tools → USB CDC On Boot → Enabled before compiling and uploading. Serial then outputs through the board's USB-C connector at 115200 baud.

🔢 6. CAN device number

The CAN device number is persisted in EEPROM and defaults to 50 when EEPROM is uninitialized. Send one of these newline-terminated commands through USB serial:

Command Result
&CANID SET <0-63> Changes the running device number immediately.
&CANID SAVE Persists the running device number and reboots the board.
&CANID GET Reports the running, saved, and default device numbers.

🔎 7. I²C scanner

i2cScanner.ino is a standalone scanner for the same GP5 (SDA) and GP4 (SCL) bus. It reports detected I²C addresses over USB serial at 115200 baud every two seconds.

📡 CAN Protocol

📤 Sensor → roboRIO (ESP32 sends sensor status)

API ID: 0x0301 (SENSOR_BASE_API_ID)

  • One frame for Sensor 0.

  • Payload (8 bytes):

Byte 0–1: Distance (uint16_t, mm)
Byte 2:   Ranging mode (0 = Short, 1 = Medium, 2 = Long)
Byte 3:   ROI center (uint8_t)
Byte 4:   ROI size X (width)
Byte 5:   ROI size Y (height)
Byte 6–7: Measurement timing budget (uint16_t, µs / 1e3 resolution)

Note: Timing budget is truncated to 16 bits (up to ~65ms).

📥 roboRIO → Sensor (ESP32 receives sensor config)

API ID: 0x0305 (SENSOR_CONFIG_API_ID)

  • One configuration frame for Sensor 0.

  • Payload (4 bytes):

Byte 0: Ranging mode (0 = Short, 1 = Medium, 2 = Long)
Byte 1: ROI center (uint8_t)
Byte 2: ROI size X (4–16, must be even)
Byte 3: ROI size Y (4–16, must be even)

Only one config frame should be sent per 200 ms to allow a safe I2C update delay.