ESP32 UART principle

[daniSi]

Hi,

In a project we are working on 9bit UART communication is need. For transmitting the data we calculate the parity bit and this works. For the incoming data luckily the most significant bit is always 0, so we basically need only 8 bits. We have figured out that the receiving still works even if we disable the parity with UART_PARITY_DISABLE. Is there any logical explanation for this? Since the transmitter (other device) sends 9N1, but the ESP is configured for 8N1, why the bytes are still correctly received?

Danijel

[ESP_Sprite]

I'd imagine about half of the bytes received will have stop bit violations. Do you see any proof of that? I don't know if the UART hardware/driver discards those bytes, but if it doesn't and only flags an error, that may be why you still see proper data.