UART Problem nrf_drv_uart.c

[Hamzus]

Hello,

I am using an NRF52832 on a Custom Board that i built myself.

I want to communicate with a PC software via UART so i've connected the TX, RX and GND ports to the USB port on PC using a TTL-232R-3V3 cable (an FTDI chip is built in it so that it should normally transform the Uart Signal to USB (Serial)) . 

I've used the app_uart_fifo.c as application layer for uart and the nrf_drv_uart.c as the Driver and it worked with an nRF52832 on a SDK but not on my Custom Board.
I debugged and i have found that my program is stuck in the While Loop (in nrf_drv_uart.c) waiting for the TXDRDY Event to be generated. 

Like i said it works fine with the SDK and the included USB cable but not with my own Configuration and i don't undestand why !
I have tested plenty of different Solutions and configurations such as Debugging the SDK where i found that it goes over UARTE and not UART so i tried this on my custom Board but then it stuck on the While Loop of the ENDTX / TXSTOPPED Event !

Thanks for your Help !!

[Kenneth]

Have you enabled hardware flow control? Make sure to disable it.

Have you looked at the serial lines on a logic analyzer to check the actual data and pin levels? Maybe you have swapped TX and RX, how about VDD, does that need to be connected to a level shifter or similar?

Best regards,
Kenneth

[Hamzus]

Hello,

Hardware flow Control is disabled i have never enabled it since i don't use CTS and RTS.

TX and Rx are also allright TX is connected to Rx and Rx to Tx and VDD i don't think i Need it because my custom Board receives Current from a Batterie connected to it !

Concerning checking the Data at the pin Level i think it is a good idea, but eather it works or not i don't have any Clue About what causes the Problem !

[Kenneth]

If you compare a logic analyzer trace you will at least be able to check if there is any data at all (for instance not mixed pins or levels), and compare timing to when it works. I think that is the best next step for debugging. Personally I use the logic analyzer from https://www.saleae.com/ 

Best regards,
Kenneth