ESP32 Forum

I am working with an ESP32-C6 and need to handle UART RX interrupts byte-by-byte without creating a FreeRTOS task. I found that uart_isr_register() is deprecated in ESP-IDF 5.0+, so what is alternate approach or any example code

Requirements
Use interrupt-based UART RX handling (without polling or tasks).
Handle incoming bytes individually inside the ISR.
Manually clear interrupt flags to avoid re-triggering

without creating a FreeRTOS task.

Any specific reason for this?

Yes, when around 100 bytes of data are received from an external source, the task waits until all bytes are received. This delay is causing a timeout in my application. If I had an ISR (Interrupt Service Routine) that triggers on each byte received, it would help handle the data more efficiently and avoid the timeout.

You can change this behavior by
1) setting a low "RX full threshold", e.g. via uart_set_rx_full_threshold(), and either
2a) using the "event-based" programming model of the UART driver (where the driver sends you "events" via a FreeRTOS queue), or
2b) reading any data via uart_read_bytes() as it becomes available, see viewtopic.php?p=147877#p147896