STM32 Black Pill Blink
STM32 Black Pill Blink is a runnable microcontroller simulation example on SensBench — open the wired circuit, inspect the code, and compile real firmware in your browser, no install needed. Last updated Aug 14, 2026.
FREE SIMULATOR EXAMPLE · BEGINNER
STM32 Black Pill Blink
This example blinks the STM32 Black Pill’s onboard PC13 LED and prints a startup banner — the fastest way to prove the F411 toolchain works. It is the Black Pill’s equivalent of hello world, identical in shape to the Blue Pill blink but running on a faster Cortex-M4 core.
| Board | STM32 Black Pill (STM32F411, Cortex-M4, 100 MHz) |
|---|---|
| Difficulty | beginner |
| Category | basics |
| Libraries | None — just the Arduino core |
| Runs in | Sensbench browser simulator — free, no account |
The exact circuit you get when you open this example — already wired, ready to run.
The sketch
// STM32 Black Pill (STM32F411CE, Cortex-M4) blink + serial.
// Onboard LED is on PC13 (active LOW).
void setup() {
pinMode(PC13, OUTPUT);
Serial.begin(115200);
Serial.println("SENSBENCH Black Pill blink");
}
void loop() {
digitalWrite(PC13, LOW); // LED on (active-low)
delay(150);
digitalWrite(PC13, HIGH); // LED off
delay(150);
}How it works
pinMode(PC13, OUTPUT) and the active-LOW toggling work exactly as on the Blue Pill: LOW lights the LED, HIGH turns it off. The loop blinks at 150 ms on, 150 ms off — faster than the Blue Pill example, showing the same code pattern at a different rhythm.
The Serial.println() banner in setup runs on USART1 at 115200. Under QEMU the Cortex-M4 core with FPU executes the same instructions, but floating-point support becomes available for sketches that need it — irrelevant for a blink, decisive for DSP-style projects.
Before you build it for real
The Black Pill’s PC13 LED is active-LOW, like the Blue Pill’s — writing HIGH turns it off, the mirror of Arduino convention. The board is 3.3 V logic only, and the F411’s pins are not 5 V tolerant: wiring a 5 V peripheral directly to a GPIO can damage the chip even though the USB connector suggests 5 V power. Under QEMU the emulation is faithful but generous — the simulator never experiences the clock-configuration hangs a real F411 suffers if the boot pins or oscillator settings are wrong.
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FAQ
How is the Black Pill different from the Blue Pill?
The Black Pill runs the STM32F411CE — a Cortex-M4 core with FPU at 100 MHz, 512 KB flash and 128 KB RAM — roughly double the Blue Pill’s F103 specs. The pin layout is a superset, and the onboard LED is still PC13 active-LOW, so blink code is identical except the boot mode and 3.3 V regulator specifics.
Why is the LED still on PC13?
The Black Pill was designed as a Blue Pill successor and kept the familiar peripherals: same PC13 LED, same USB connector position. Only the voltage regulator and pin headers grew. That continuity means beginner sketches port across the family unchanged.