Thanks for reply,

I understood you said. I would like overwrite handler. I tried use uart_isr_free() after uart_drive_intall(), then use uart_isr_register(), but this did not work as I would like, also the timer interruption stopped.

You have some idea how solve this?

Hello, I'm using some ESP32 resources, like: Timer, UART and Interrupts. Basically, I send a standard UART frame stream each 500ms. Until now, no problem. But, when I try get UART_TX_DONE_INT event via interrupt, I can not. I need this to get moment of transmitter send out all TX_FIFO data bytes. In...