Fanstel boards not connecting to each other?

[SRall]

I have a few different Fanstel Eval boards that contain the nRF52840 SoC - starting with the BT840XE. I'm able to flash the board with example firmware and my own custom firmware successfully. The Nordic Blinky examples have been working just fine with the Fanstel board acting as central and a Nordic DK as the peripheral and vice versa. Same goes for the Fanstel connecting to my phone via the nRF Connect app. LED Button service is observed as functioning properly every time for both peripheral and central blinkys flashed to the Fanstel board. 

Problem arises when implementing the blinky example with two Fanstel boards. I flash one with peripheral and the other with the central (unmodified hex examples right out of the SDK15.2). No connection is established between the two Fanstel boards. At first I thought it was a faulty board, so I pulled out a Fanstel BC840E and went through all the above troubleshooting combinations - still no connection between two Fanstel boards at all. No matter what I try. The Fanstel boards are unchanged from how they were shipped right out of the box (there are some tact switches on the board, but I haven't touched them).

I am in contact with Fanstel support, but they seem to be just as puzzled as I am. Has anyone had trouble with this?

Thanks for your time, 

Sam

[Kenneth]

Hi,

The default nRF5 SDK examples are setup for instance to use external 32kHz crystal, there may also be GPIO's that expect UART hardware flow control connected. So if you are not able to connect you should check by debugging where in your projects the code "hangs" and/or there is any asserts.

If this module also have a PA, you would likely also need to add control of the PA for it to work as expected. Also make sure that your previously used phone don't by accident connect to one of the boards by default.

Best regards,
Kenneth

[SRall]

Thanks for your response Kenneth. I was provided the additional source code needed to control the PA and eval board pin configs, and I believe I have the external crystal switched to "ON".

You're right though, I'm a little confused about the UART configuration, as I don't seem to be getting anything to print over the serial COM (I'm using PuTTY and a Nordic DK for the J-Link ). I noticed that this additional code has hardware flow control turned off and the UART RX and TX pins are set to P1.01 and P1.02 respectively. Is this what is causing this issue?

I am compiling the 'Debug Build Configuration' in SE Studio, but I wonder if I have a setting wrong somewhere in the IDE? 

I can at least confirm the board enters the main function because I can see the LEDs initialize by turning them on and off again. I can actually control how long the LEDs flash by increasing the delays in the init function, so I at least I can confirm the code is flashed and executing properly. 

It could very well be that the two Fantel boards are, in fact, establishing a connection and I just have no way of knowing it because I can't get any debug logs to print. 

Thanks again for your help, 

Sam

[Kenneth]

Try to pull the UART RX pin high if it's unconnected, that should at least avoid uart framing errors. Else I think debugging through SES to identify where it potentially is hanging, asserting or loop'ing is the way to go yes.

Best regards,
Kenneth

[Tesseract]

Any update on this. I have exactly the same issue.