To power nRF52840 DK using USB cable

[chandrakant]

Hi,

I am developing custom board with reference to nRF52840. For that I am using nRF52840 DK for programming, but meanwhile board is not getting power from USB cable. Battery is connected. But if I want to source the power supply from USB cable while programming then what should be done? Kindly, resolve the query for same.

Thanks & Regards,

Chandrakant

[awneil]

You mean you want your custom board to be supplied with power from the DK's USB connection?

The Debug Out from the DK does not supply power to the Target - so you will have to make an additional connection for that.

[chandrakant]

No, not for custom board. I am referring DK, for that the power supply should be given through USB cable. So what configuration I must do?, So that my DK will take the power supply from USB cable instead of battery.

[awneil]

What does the User Manual for the DK tell you?

What "battery"  are you referring to?

[chandrakant]

The battery is coin cell battery from which board source the power. But I need the configuration for USB power supply from USB cable. In User Manual, I didn't got  clear information about config for the same. I have little bit confused in switches they have mentioned for the power supply.

[awneil]

Remember that we can't read your mind, and we can't see what you're doing, and we can't see how you have everything set up.

Therefore you need to clearly explain these things!

Are you talking about the coin cell on the DK ?

Have you looked at the DK schematics to see how the power routing works?

[chandrakant]

Sorry. I have DK and am using that. My doubt is that, when I connect DK to my PC using USB cable, then whether my board (DK) is getting power supply from USB cable? or I need to config the DK in order to get power supply from USB cable which is connected to PC.

I have gone through schematic for the same. They have mentioned one switch for that and is having three terminals i.e. VDD, USB and LI-Po. I have put the switch on USB then my DK is not working at all. But when I switch to VDD the my DK board is powered up. So, I have little confusion in between these things.

Anyway I need to give power supply to DK through USB that is my question.

[haakonsh]

There are two USBs on the DK, The J2 connector powers the DK and communicates with the J-link OB debugger chip, the J3 connector called nRF USB is connected to the nRF52840s USB pins. 

The nRF Power Source switch on the DK determines what voltage source supplies the nR52840, the J2 USB connector when set to VDD, and the nRF USB connector when set to USB.