Blue Pill lamp
A lamp on a Blue Pill that blinks in step with the board’s own LED, because both hang off 3.3 V and PC13 sinks them. The whole build, an STM32 Blue Pill and 2 more parts, runs here in your browser on the firmware below; open it in the editor to change the wiring or the code and run it again.
StarterRuns in your browser. Free, and no account needed.
The code
The firmware exactly as the editor opens it. Change a line there and press Run: it compiles in the browser.
// Blink: the smallest thing a board can do.
//
// The Blue Pill's green LED sits between the 3.3 V rail and PC13 through a
// 1 k resistor, so driving the pin LOW lights it and HIGH turns it off. That
// is the opposite of the Uno's, and it catches everybody once.
//
// Wire an LED and a 220 ohm resistor from PC13 to 3V3 to see the same thing on
// the breadboard.
//
// delay() parks the core on WFI between SysTick ticks rather than spinning, so
// this sketch costs the simulator almost nothing while it waits.
void setup() {
pinMode(LED_BUILTIN, OUTPUT);
}
void loop() {
digitalWrite(LED_BUILTIN, LOW); // lit
delay(500);
digitalWrite(LED_BUILTIN, HIGH); // dark
delay(500);
}
Parts list
4 parts, plus the jumper wires. Every one is in the editor's parts bin.
How it is wired
3 connections, pin by pin, read from the circuit itself. Each line is one set of pins joined together, by a jumper wire or a breadboard strip.
- STM32 Blue Pill (F103) pin PC13; LED, green pin C
- STM32 Blue Pill (F103) pin 3V3; Resistor, 220 Ω pin 1
- Resistor, 220 Ω pin 2; LED, green pin A
Change it and keep it
Open it in the editor, change the circuit or the code, and keep your version in a free account.