Ini
[env:esp32-c3-supermini]
platform = espressif32
board = esp32-c3-devkitm-1
framework = arduino
monitor_speed = 115200
board_build.flash_size = 4MB
build_flags =
  -D ARDUINO_USB_MODE=1
  -D ARDUINO_USB_CDC_ON_BOOT=1

Cpp
#include <Arduino.h>
#include <WiFi.h>
#include <NimBLEDevice.h>

static constexpr uint8_t AIN1=0, AIN2=1, PWMA=3;
static constexpr uint8_t BIN1=4, BIN2=5, PWMB=6, STBY=7;
static constexpr uint32_t FAILSAFE_MS=500;
static uint32_t lastCommandMs = 0;
static bool armed = false;

void motorStop() {
  ledcWrite(PWMA, 0);
  ledcWrite(PWMB, 0);
  digitalWrite(AIN1, LOW); digitalWrite(AIN2, LOW);
  digitalWrite(BIN1, LOW); digitalWrite(BIN2, LOW);
  digitalWrite(STBY, LOW);
  armed = false;
}

void motorSet(uint8_t in1, uint8_t in2, uint8_t pwmPin, int speed) {
  speed = constrain(speed, -255, 255);
  digitalWrite(in1, speed > 0);
  digitalWrite(in2, speed < 0);
  ledcWrite(pwmPin, abs(speed));
}

void applyCommand(int left, int right) {
  if (!armed) {
    digitalWrite(STBY, HIGH); // reaches driver only while hardware RUN/ENABLE is closed
    armed = true;
  }
  motorSet(AIN1, AIN2, PWMA, left);
  motorSet(BIN1, BIN2, PWMB, right);
  lastCommandMs = millis();
}

void setup() {
  pinMode(STBY, OUTPUT);
  digitalWrite(STBY, LOW); // first safety action
  pinMode(AIN1, OUTPUT); pinMode(AIN2, OUTPUT);
  pinMode(BIN1, OUTPUT); pinMode(BIN2, OUTPUT);
  ledcAttach(PWMA, 20000, 8);
  ledcAttach(PWMB, 20000, 8);
  motorStop();

  Serial.begin(115200);
  WiFi.mode(WIFI_STA); // Wi-Fi may be connected/configured by application
  NimBLEDevice::init("ESP32-C3-Robot"); // controller supports Wi-Fi/BLE coexistence
  lastCommandMs = millis();
}

void loop() {
  // Network/BLE handlers must call applyCommand(left,right) for each valid packet.
  // Any disconnect handler should call motorStop() immediately.
  if (armed && (millis() - lastCommandMs > FAILSAFE_MS)) motorStop();
  delay(2);
}

1. Configure STBY output low before all other actuator pins.
2. Configure direction and PWM; command zero duty.
3. Start Wi-Fi and BLE services.
4. Require an authenticated/fresh motion command before raising STBY.
5. Stop immediately on Wi-Fi/BLE disconnect, malformed command, watchdog/reset, or 500 ms command timeout.
6. Hardware RUN/ENABLE must also be active; firmware cannot override an open hardware chain.