nrf51822 EK current measurement - SB8

RE: nrf51822 EK current measurement - SB8

Rafal — Mon, 30 Dec 2013 09:39:06 GMT

I am afraid that you will have to cut bridges at UART lines - in my case this was necessary to measure current consumption when board is powered over USB.

RE: nrf51822 EK current measurement - SB8

Anthony Ambuehl — Mon, 23 Dec 2013 20:42:53 GMT

I have newer revision board and encountered the same issue. After cutting SB8 and toggling the switch the device was still powered by the usb. I don't really want to cut the other solder bridges so I'm powering off the battery instead.

Could the eval kit user's guide please be updated to give corrected instructions on how to perform power measurements?

RE: nrf51822 EK current measurement - SB8

Rafal — Mon, 09 Dec 2013 21:42:17 GMT

After cutting SB9-12 bridges (not only SB8) board works as it should - without a jumper on P1 header uC won't be powered. I am not sure if it is desired behaviour, but without this board will be powered from USB even though SB8 is cutted.

Thank you Hakon for your help.

RE: nrf51822 EK current measurement - SB8

Rafal — Fri, 29 Nov 2013 10:05:33 GMT

Hi Hakon,

I have a newer HW revision. I will try to cut those bridges today because setting switch in the OFF position didn't solve the problem. I will let you know whether it helps me.

Best regards, Rafał

RE: nrf51822 EK current measurement - SB8

Håkon Alseth — Thu, 28 Nov 2013 11:42:13 GMT

You do not need to cut the wires on the SWD interface, you can just remove the jumpers on P8, or if you have a newer HW revision of the board, set the switch in the "OFF" position.

If that does not work, there are solder-bridges marked "CTS/RTS/TxD/RxD" between the SEGGER and the nRF that can be cut and later on re-soldered if you're using UART communication.

RE: nrf51822 EK current measurement - SB8

Rafal — Thu, 28 Nov 2013 11:34:08 GMT

Thank you Hakon for your response. I could try cutting this jumpers, but not sure if it is a great solution. After that I won't be able to use some of the board functionalities. If I am right it is not Ok that board is powered through different pins then VDD?

Best regards, Rafał

RE: nrf51822 EK current measurement - SB8

Håkon Alseth — Wed, 27 Nov 2013 13:36:52 GMT

Hi Rafal,

It could be sourced by the P8 header (SWD interface) which is connected to the SEGGER chip. A possibility can also be the UART lines from the SEGGER.

Try cutting/removing jumper on these lines and see if that helps the situation.

BR Håkon