Pinout & Headers

All traces, driver sockets, and headers are routed directly on the EVDrive PCB.

Here are the exact schematic pin definitions, dual I2C buses, and connector layouts to use in your code.

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ESP32-S3 Pin Mapping

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Dual Independent I2C Buses

Standard AS5600 magnetic encoders have a fixed, non-configurable I2C address (0x36).

Instead of requiring an external I2C multiplexer chip, the EVDrive PCB routes two separate physical I2C buses directly to the ESP32-S3:

• Bus 1 (Wire on GPIO 1 / GPIO 2):
  • Connects to the MPU-6050 gyro module (0x68).
  • Connects to Encoder A header J1 (0x36).
  • Hardware 4.7kΩ pullups on board (R10, R11).
• Bus 2 (Wire1 on GPIO 41 / GPIO 42):
  • Connects to Encoder B header J2 (0x36).
  • Hardware 4.7kΩ pullups on board (R12, R13).

Both encoders can be queried simultaneously in code without any address collisions.

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Onboard Battery Voltage Monitoring

The board includes an onboard precision voltage divider wired to GPIO13:

• Top Resistor ($R_4$): 100 kΩ connected to +12V
• Bottom Resistor ($R_5$): 10 kΩ connected to GND
• Divider Ratio:

$V_{\text{battery}} = V_{\text{GPIO13}} \times \left(\frac{100\,\text{k}\Omega + 10\,\text{k}\Omega}{10\,\text{k}\Omega}\right) = V_{\text{GPIO13}} \times 11.0$

A 12.0V battery outputs approximately 1.09V on GPIO 13, which sits safely inside the ESP32 ADC range.

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Headers & Connectors

Encoder Connectors (J1 & J2)

Vertical 4-pin keyed JST-XH connectors (B4B-XH-A, 2.50mm pitch) designed for custom RH Circuits AS5600 breakout boards. Keyed shrouds prevent reverse insertion and provide positive retention under vibration:

• Pin 1: +3V3 (Regulated 3.3V logic supply)
• Pin 2: GND (Ground)
• Pin 3: SCL (I2C Clock: J1 routes to GPIO 2, J2 routes to GPIO 42)
• Pin 4: SDA (I2C Data: J1 routes to GPIO 1, J2 routes to GPIO 41)

Motor Screw Terminals (J11 & J12)

Dedicated 4-pin 2.54mm pitch screw terminal blocks (J11 for Motor A / Left, J12 for Motor B / Right) wired directly to TMC2209 driver outputs (U3 and U4). Stripped motor lead wires clamp directly under screws to prevent disconnection during runs or handling:

• Pin 1: M1B (Coil 1, Phase B)
• Pin 2: M1A (Coil 1, Phase A)
• Pin 3: M2A (Coil 2, Phase A)
• Pin 4: M2B (Coil 2, Phase B)

Power Input Terminals (KF301 5.0mm Pitch Screw Terminals)

• J4 & J9 (12V Motor Power IN): Dual parallel 2-pin screw terminals for motor power input (12V–24V).
  • Pin 1: GND (-)
  • Pin 2: +12V IN (+)
  • Protected by 5A fuse F1 and reverse-polarity P-channel MOSFET Q1 (AO4407A).
• J5 (5V Logic Power IN): 2-pin screw terminal for 5.0V regulated logic input.
  • Pin 1: GND (-)
  • Pin 2: +5V IN (+)
  • Protected by 2A fuse F2 and reverse-polarity P-channel MOSFET Q2 (AO4407A).

Auxiliary Ground Header (J10)

A dedicated 3-pin 2.54mm vertical header where all pins are tied directly to board GND. Provides convenient ground tie points for auxiliary sensors, scopes, or test probes without crowding terminal blocks.

Expansion GPIO Header (J6)

A 10-pin 2.54mm header for extra sensors, bumper switches, or custom add-ons:

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Status LEDs