Building an STM32 Flight Controller From Scratch

August 26, 2026

Sending "Hello World" Over SPI and Verifying It on the Wire

I've moved from GPIO and interrupts into serial communication on my STM32F407 flight controller.

In the latest development log, I configure SPI2 as a master, transmit "Hello World" using my own SPI driver and connect a logic analyzer directly to the STM32 to verify the resulting clock and data signals.

The analyzer lets me validate both the decoded message and the individual clock edges produced by the hardware.

char user_data[] = "Hello World";

SPI_SendData(
    SPI2,
    (uint8_t *)user_data,
    strlen(user_data)
);