Documentation

// STM32F411 Black Pill - Blink Example (PC13 user LED)
// Board: "Generic STM32F4 series" -> "BlackPill F411CE"
// Upload method: USB DFU (hold BOOT0, tap NRST first time)

#define LED_PIN PC13   // User LED is on PC13 (active LOW)

void setup() {
  pinMode(LED_PIN, OUTPUT);
}

void loop() {
  digitalWrite(LED_PIN, LOW);   // ON
  delay(250);
  digitalWrite(LED_PIN, HIGH);  // OFF
  delay(250);
}

// STM32F411 Black Pill - Print to Serial Monitor over USB CDC
// In the Tools menu, set "USB support" to "CDC (generic Serial supersede U(S)ART)".

void setup() {
  Serial.begin(115200);
  while (!Serial) { /* wait for USB enumeration */ }
}

void loop() {
  Serial.print("Uptime: ");
  Serial.print(millis() / 1000);
  Serial.println(" s");
  delay(1000);
}

// STM32F411 Black Pill - I2C Bus Scanner
// Default Wire bus uses I2C1 on PB6 (SCL) and PB7 (SDA).

#include <Wire.h>

void setup() {
  Serial.begin(115200);
  while (!Serial) {}
  Wire.begin();
  Serial.println("\nI2C Scanner");
}

void loop() {
  byte found = 0;
  for (byte addr = 1; addr < 127; addr++) {
    Wire.beginTransmission(addr);
    if (Wire.endTransmission() == 0) {
      Serial.print("Found device at 0x");
      if (addr < 16) Serial.print('0');
      Serial.println(addr, HEX);
      found++;
    }
  }
  Serial.print(found);
  Serial.println(" device(s) found.\n");
  delay(2000);
}

# STM32F411 Black Pill - MicroPython Hello World
# Flash the official MicroPython STM32F411 firmware first.
# Then connect via USB serial and run this script.

from pyb import LED, Pin, delay

led = LED(1)  # PC13 user LED maps to LED(1) on most ports

while True:
    led.toggle()
    delay(250)