nRF Connect SDK - LPUART not working nRF52840 and GSM

[jitendra_cf]

Hi,

I have been trying to interface GSM modem with nRF52840 using LPUART (nRF Connect SDK).  I have used below pins for connections:

nRF52840                -           GSM

P0.21 (TX)                -           RX

P0.22 (RX)                -           TX

P0.23 (REQ)              -           RTS

P0.24 (RDY)               -          CTS

I have tried lpuart sample code for AT command with async mode but the firmware crashes always. I didn't find any response from modem.

I also tried to revered REQ and RDY pins but got the same issue.

Can anyone help me to make it work ? Can you please verify the above connections ?

Thanks in advance.

 

[jitendra_cf]

Hi,

I do not have scope right now. So can not check pins status. 

I would like to know about feasibility of using lpuart between nRF52 and external gsm module.

Jitendra

[Håkon Alseth]

Hi,

 

My apologies, I can confirm that lpuart is not compatible with standard UART hardware flow control. In your case, you need to use uart in a standard way (either with or without flow control). I will request that this is documented clearly in the lpuart documentation.

 

Kind regards,

Håkon