POC to drive M5 Balancer Robot I2C base with motors.

M5BalaMotorCode.ino

#include <Wire.h>

#define M5GO_WHEEL_ADDR     0x56
#define MOTOR_CTRL_ADDR     0x00
#define ENCODER_ADDR        0x04
#define DEAD_ZONE           5

void setMotor(int16_t pwm0, int16_t pwm1) {
  Wire.beginTransmission(M5GO_WHEEL_ADDR);
  Wire.write(MOTOR_CTRL_ADDR); // Motor ctrl reg addr
  Wire.write(((uint8_t*)&pwm0)[0]);
  Wire.write(((uint8_t*)&pwm0)[1]);
  Wire.write(((uint8_t*)&pwm1)[0]);
  Wire.write(((uint8_t*)&pwm1)[1]);
  Wire.endTransmission();
}

void setup() {
  // put your setup code here, to run once:
  Wire.begin();
  delay(100);
  Wire.beginTransmission( M5GO_WHEEL_ADDR );
  uint8_t error = Wire.endTransmission();
  if ( error ) ESP_LOGI( TAG, "no motors" );  
  setMotor( 0,-0 );
}

void loop() {
  int16_t power = time(NULL) % 256;

  setMotor( power, 0-power );
  delay(1000);
}