TWI Scanner Example is not Working in Custom Board (NRF52840)

[namitha K M]

Hi,

1. Here I am using the nrf52840 in my customized board, in parallel I have nrf52840 dev board. In My custom Onboard debugger is not available so I am using SWD to load the program from NRF52840 DK board to Custom Board (NRF52840).

2. I am loading TWI Scanner Example program to my custom board, from that nothing is displayed on terminal, But If I am flashing same TWI scanner example to Dev boards its working and its displaying like TWI Scanner Started But in my custom board nothing is displayed. 

3. I have mention I2C pin as P0.06 & P0.07, and also I have mention UART in my custom board as P1.11(TX), P1.12(RX), P1.10(CTS), P0.30(RTS).

My doubt why log is not displaying anything in my custom board. and one more doubt also whether I have to mention custom board UART pins in TWI Scanner Example??

I have raised this questions in my previous thread, there is no reply that's why I posed this thread. Please anyone help me on this. I am waiting for your quick response...

Thanks in advance.

[Susheel Nuguru]

2. I am loading TWI Scanner Example program to my custom board, from that nothing is displayed on terminal, But If I am flashing same TWI scanner example to Dev boards its working and its displaying like TWI Scanner Started But in my custom board nothing is displayed. 

Jansi, 

Please connect the TWI pins to the logic analyzer or similar and see if there are any data TWI data being transmitted/received on these pins.

Please notice the TWI is not used in NRF_LOG. NRF_LOGGER module only uses UART/RTT or Flash as the backend and not TWI. The TWI data that you are transmitting/receiving in your firmware cannot be seen in the terminal, but the NRF_LOG statements that you have in your firmware should be transmitted on the UART pins and using your TTL/FTDI connections, you should be able to redirect them to your computer USB board into a virtual com port. 

1. Please check on your UART pins using a logic analyzer to see if there is any data that is being transmitted on uart pins? If you can see the expected data on the pins using the logic analyzer,
2. then check to see the FTDI connections and then
3. check if you have configured the COM terminal on the computer with correct baudrate and other settings like flow control etc..

If you still have problem seeing your firmware NRF_LOG data on serial terminal then post me the snapshots of

1. Check the backend you are using for the firmware in your custom board. I am assuming you are using uart as backend.
2. Logic logic analyzer to all four uart pins and take a snapshot of Logic analyzer data showing that the NRF_LOG data is being transmitted to the UART pins. 
3. your FTDI connections picture
4. Your com port terminal settings matching the serial backend you use. Like baudrate, stop/parity bit and hardware flow control setting.

This was supposed to be a very simple task to see your serial data of your custom board. Not sure what is wrong without seeing your logic analyzer snapshots.

[namitha K M]

Hi,

Thanks for the reply.

Please notice the TWI is not used in NRF_LOG. NRF_LOGGER module only uses UART/RTT or Flash as the backend and not TWI -->How to to change backend flashing option in firmware. 

I don't have Logic analyzer, can you please tell me alternate way to check the data. 

Thanks in advance.