Coap server not working on a third party module

[kaushalyasat]

Hi, 

I am building the CoAP client and sever example programs on a third party module (Reytac MDBT50Q). I am using Reytac dev board  MDBT50Q-DB-40. Unfortunately the example apps doesnt seem to work. I am using NRF Connect SDK 2.0.0. I tried the apps on Nordic nRF52840 Dev Kits and they work. I am using the same nrf52840dk_nrf52840.dts file with the Reytac module. 

The Reytac dev board doesn't have the HFX oscillator on the dev board, probably it is available in the module itself. The dev board has a 32.7kHz crystal and is oscillating Vpp ~100mV. Dont know if this is too low. I couldnt find a spec for the LFXO in the datasheet.

When I look into the power supply on Dev board, I see VDDH tied to 3V3 and 10uH inductor between VDD and DCH. I reckon this means the power path would be 3V3->VDDH->REG0 DC/DC->REG1 (LDO or DC/DC)->System Power. I couldnt find the code section which handles the power control registers in coap client app. 

1. Is 100mV LFXO acceptable?
2. Where is power register configuration happens in coap client/server apps?

Thanks,

[kaushalyasat]

Use of "button_3' in the CoAP client is to send a provisioning request. This code is not mine, it is the CoAP client example project from the NRF connect SDK.

static void on_button_changed(uint32_t button_state, uint32_t has_changed)
{
	uint32_t buttons = button_state & has_changed;

    ...
    
	if (buttons & DK_BTN4_MSK) {
		coap_client_send_provisioning_request();
	}
}

 

This is where it is used to invoke in coap_client.c to call 'coap_client_send_provisioning_request ()' function.

[Edvin]

Are you sure whether any of the packets in the sniffer trace are actually from the device you are testing (which is failing), or can the issue be that there are no packets on the air at all?

I don't remember by heart what registers that are used, but can you please try to read out these registers:

nrfjprog --memrd 0x10000060

nrfjprog --memrd 0x10000064

nrfjprog --memrd 0x100000A4

nrfjprog --memrd 0x100000A8

And let me know what these return?

Best regards,

Edvin

[kaushalyasat]

I can assure that during the packet capture there were only one server and one client in operation. 

The register contents of the client (Minew module) are as follows.

Register	Contents	Notes
0x10000060	0x78FB6AA5	FICR.DeviceID[0]
0x10000064	0xBB6363D5	FICR.DeviceID[1]
0x100000A4	0xD72EEB40	FICR.DeviceAddress0
0x100000A8	0x9CE7ACC0	FICR.DeviceAddress1

Cheers,

[kaushalyasat]

Hi Edvin,

I managed to solve it. The issue was when I created the custom module based on nrf52840dk, I have missed the nrf52840dk_nrf52840.overlay file ( I had a similar file but it was all blank in my custom board def folder). After I moved this as nrf52840dk_nrf52840_Minew.overlay to my board folder, everything is working. 

I can see the packet transmission in wireshirk as well. 

Thanks you for all your help.

Cheers,