Power measurement with external power supply

RE: Power measurement with external power supply

Sameer — Fri, 12 Apr 2019 05:23:58 GMT

Thanks Stian,

It is working with these settings.

Sameer

RE: Power measurement with external power supply

Stian Røed Hafskjold — Thu, 11 Apr 2019 16:23:47 GMT

Hi, I tried now with the zigbee light switch example, and it works with the setup you described.

Power through P21
SW10 to ON
SW6 to nRF only
SW9 to VDD
Plug in the USB cable (J2), to power the rest of the board
SB40/SB41 closed

With that setup I'm able to measure current going in to P21 and still toggle the light with the buttons.

RE: Power measurement with external power supply

Sameer — Tue, 09 Apr 2019 08:40:53 GMT

Hello Sitan,

Did you try running this setup?

Please let me know if any additional info is required.

Regards,

Sameer

RE: Power measurement with external power supply

Sameer — Fri, 05 Apr 2019 09:44:21 GMT

The application is based on light switch example. I have just added a timer to periodically send a message. As soon as the client is powered on it starts sending packets to the server. No other changes on the application.

Kindly try running this. If you can share some info on, how can I power the rest of the board along with external supply 3.3v through P21 (with SW10 on, SW9 at Vdd and sw6 at nrf_only)? It will be helpful.

Regards,

Sameer

RE: Power measurement with external power supply

Stian Røed Hafskjold — Fri, 05 Apr 2019 09:19:10 GMT

Have you enabled UART, UART logging, RTT logging or similar, or are you using any other peripherals on the board, like the nRF USB port, or external flash?

Is your code based on any of the examples from the SDK? If so, I can try it out here and see what happens.

RE: Power measurement with external power supply

Sameer — Thu, 04 Apr 2019 18:41:52 GMT

Thanks Stian,

I am running one simple application where client is periodically sending few packets to server. The boards are provisioned and configured. So when I connect the external power supply with all other right settings (as mentioned above) on the client board, the server should receive the packets (I am powering the client with external supply and server is still powered through USB). But server doesn't receive any packet. So I believe the board is not running. What can be wrong here?

Can we also power the board with Vin pin on the P20?

Regards,

Sameer

RE: Power measurement with external power supply

Stian Røed Hafskjold — Thu, 04 Apr 2019 14:48:28 GMT

Hi, seems like your setup is correct. When you say "the board is not running" with this setup, do you mean the nRF52 chip or the board itself? What do you need to run on the board? So the point of SW10 is to bypass the components on the DK powering the nRF52 chip directly. You should also set SW6 to nRF ONLY. Now you can measure current. If you need to use the JLink on the DK you need to set SW10 back to the OFF position.

It's true that USB has to be connected on order to power "the rest" of the board. This is so that the components are not floating and not interfering with the operation of the nRF52 (more specifically the reset and SWD lines).