TTL HMI to NRF52840

[MontanaEE]

Working with a Pinnacle 100 using an NRF52840.  I have a HMI with a TTL serial interface.  I have verified I/O on the HMI itself via a TTL/USB converter to Tera term, but having trouble with TTL comm to the NRF.  Is there sample code available to reference for setting up the port for this.

[MontanaEE]

I am using the Laird Connectivity Pinnacle 100 DVK.  https://docs.zephyrproject.org/latest/boards/arm/pinnacle_100_dvk/doc/index.html

This DVK uses Zephyr RTOS.  I am a first time Zephyr user so picking that up as I work through this.

I have a UART available on the DVK, but I do not see the data from the touchscreen coming in on the port.  I can connect the same touchscreen to a TTL to USB converter and see the touchpoint ID's come through on TeraTerm with no issue,  so I know that is functioning.  There is a direct USB port to the NRF52840 on the DVK.  Is there a way to monitor the other UART port to see what is coming through besides just getting the echo back on the port?  This is a 3.3V TTL signal which should be compatible with the UART I believe.

[MontanaEE]

The SDK version I have is 2.5.0

[JONATHAN LL]

MontanaEE said:

Is there a way to monitor the other UART port to see what is coming through besides just getting the echo back on the port? 

Do you have a logic analyzer or a Oscilloscope that you can probe the lines with to see what is happening on the line? 

TP 13 and TP 14 is USB lines test points. 




Regards,
Jonathan

[MontanaEE]

Jonathan,

Thank you for the response.  Yes, I do have an o'scope.  The board I am using is the Laird Pinnacle 100 DVK.  It has a UART port that I can access the TX/RX pins on.  Am I correct that for the 3.3V TTL Serial, I would connect to the UART TX and RX?    If so, I was trying to find out how to view the data so I can debug the HMI.

Thanks,

Stephen

[Sigurd]

Hi,

Jonathan is out of office, so I'm replying instead.

MontanaEE said:

Am I correct that for the 3.3V TTL Serial, I would connect to the UART TX and RX? 

Correct.

MontanaEE said:

If so, I was trying to find out how to view the data so I can debug the HMI.

Personally, I prefer saleae logic analyzer, but there are other options on the marked as well.

[MontanaEE]

Thank you.  I will see what I can find for an LA.  I have everything connected as it should be then.