Wiring Diagram

Complete wiring reference for connecting all Data Walker components.

ESP32 Pin Assignments

ESP32 PinFunctionConnected To
GPIO 34Hall Sensor InputRJ22 Pin 2 (Signal)
GPIO 21I2C SDAOLED Display SDA
GPIO 22I2C SCLOLED Display SCL
3.3VPowerHall Sensor VCC, OLED VCC
GNDGroundHall Sensor GND, OLED GND
GPIO 0Button 1Menu/Select (optional)
GPIO 35Button 2Back/Cancel (optional)

RJ22 Connector Pinout

The Hall sensor connects via a 4P4C (RJ22) connector:

RJ22 PinWire ColorFunction
1RedVCC (3.3V)
2GreenSignal (to GPIO 34)
3Not connected
4YellowGND

I2C Address

The OLED display uses the default I2C address:

0x3C

Pull-up Resistors

The I2C lines require pull-up resistors. Most OLED modules have these built-in. If your display does not, add 4.7kΩ resistors from SDA and SCL to 3.3V.

Hall Sensor Wiring

The Hall sensor (SS41 or equivalent) has 3 pins:

  • VCC: Connect to 3.3V (through RJ22 Pin 1)
  • GND: Connect to ground (through RJ22 Pin 4)
  • OUT: Connect to GPIO 34 (through RJ22 Pin 2)

GPIO 34 has an internal pull-down resistor. No external resistor is needed.