I was trying to make two of my STM32F4 disco boards (let’s call it MCU A and B) talk to each other using Zephyr uart async api but for some reason I kept getting 00 bytes on the receiver side (MCU B).

In the overlay, I used Usart1 for the communication between two, while the default one (usart2) is used for debugging or serial monitoring

Best way, I’ve found, to troubleshoot data bus issues is to get an analyzer on those pins. That way you can see if they’re toggling correctly or there’s something wrong. Don’t forget to match TX>RX RX>TX. I’ve done that wrong a couples times 😉

Terms and Conditions | Privacy Policy