ESP32 Forum

Hello Team Support and esp32 developers,

Can you provide me with a sample code or a driver library for using the UART for Tx and Rx over the DMA (uhci).!
The uhci driver is still not available in esp-idf, but I found before post about some one who had contact the support team for the uhci and sample code and they sent it to him which runs OK for him as he stated.
please, I need this uart dma library and sample code.

Thanks,

Hello guys,

any help or support ?!

Hi, @eng.m_mahmoud
This is the UHCI example, but please know that this is just an example, it may be unstable. you can refer to it and rewrite your own driver
thanks !!

Dear ESP,

by "unstable", do you mean that the open source implementation of hal functions can be unstable (where using the registers directly could still result in stable functionality if coded right), or do you mean there is silicon errata that would make dma uart access inherently unstable/unreliable?

it is not clear to me if currently known dport/ahb/apb issues or uart errata only apply to esp32 rev 1, or also esp32 rev 3, and possibly also to s2 , s3, or even c3 chips?

@ESP_houwenxiang the file is damaged. Could you provide a new one?

Hi, I tried to make the same example for esp32-s3.
As far as I can see, some of the UHCI register features are transferred to the GDMA registers.

*Do we have a better choice than register-level programming to use DMA for UART?
*Or is there a sample code for esp32-s3?
*And finally, is there an ESP_IDF API that uses the UART DMA feature?

Thank you for your time, and have a nice day!

Hi,

We need esp32-s3 uart with dma here as well.
So my questions are:

* Can the uhci_test code you posted be used with esp32-s3, too ?
* What does the normal uart driver do under the hood ?
(Maybe the driver already employs dma ?)

Best Regards,
jstoefer