Instructions for setting up 9160 DK for current measurement are confusing

RE: Instructions for setting up 9160 DK for current measurement are confusing

Bjørn Kvaale — Fri, 03 May 2019 08:08:12 GMT

You can use the same method as in my answer. You will however need to use a good anmeter or supply (e.g. agilent 6705) to get accurate readings. Cheap anmeters will often integrate multiple current measurement readings together, so the value shown on the display may not be that accurate with respect to time.

RE: Instructions for setting up 9160 DK for current measurement are confusing

Bjørn Kvaale — Fri, 03 May 2019 08:00:07 GMT

isurki Just follow the user guide v0.7.1. You can see that the v0.7.1 has been updated for the v0.8.5 DK here. I agree it is slightly confusing with the versioning. The user guide version is not the same version as the DK version.

RE: Instructions for setting up 9160 DK for current measurement are confusing

Ahmed Elhaddad — Fri, 03 May 2019 07:47:02 GMT

Hi Bjørn,

How can I measure the current consumption by the module during different phases (uplink payload data transmission, during the inactivity timer duration, ..etc) using the above method?

The version of my kit is 0.8.2.

Regards,

Ahmed

RE: Instructions for setting up 9160 DK for current measurement are confusing

isurki — Thu, 02 May 2019 06:59:52 GMT

Hi,

I have v0.8.5 nRF91 DK. For what i've undertood, this answer is not valid for my DK? How do I have to set up my board to make the current measurements?

the latest user guide I found is for the v0.7.1, i haven't found the documentation for the v0.8.5, is there any newer documentation?

Thanks!

RE: Instructions for setting up 9160 DK for current measurement are confusing

Bjørn Kvaale — Mon, 11 Mar 2019 13:30:08 GMT

The answer I posted should be valid for v0.7.0 too. As posted in the answer, switch 10 is not needed for current measurement.

RE: Instructions for setting up 9160 DK for current measurement are confusing

medard.rieder — Wed, 06 Mar 2019 08:00:42 GMT

my board does not have Sw10. It is version 0.7.0

how to measure in this case ?

RE: Instructions for setting up 9160 DK for current measurement are confusing

Bjørn Kvaale — Fri, 18 Jan 2019 12:21:42 GMT

Update: This answer is valid for nRF91 DK v0.7.0, v0.8.2, v0.8.3 & v0.8.4. Not valid with the latest v0.8.5 nRF91 DK! There is a bug in the user guide v0.7. Without SB44 cut, the U25 switch leaks current, which could lead to the high current readings. It should look like this:

You will need to cut the SB44 on the nRF91DK. This will disable switch U25 & therefore it does not matter which position SW10 is in.

"Measuring current using the DK guide setup will give bad results. The switch (U25) leaks current from VOUT to GND even when off.

Pin closest to USB connector is pin3
1. Measure current using an ammeter: Connect to pins 1 and 2
2. Measure current using a supply like Agilent 6705: Connect to pins 1 and 3.
3. Accidentally shorting pins 2 and 3 -> dead DK! So be careful, remove USB power before connecting your measurement probes.

To make the board work again using USB power only, short pins 1 and 2."

Summary:

Flash the secure boot & the app to the nRF91 via usb, remove the usb cable, then cut the SB44 & power the board via a PSU on connector P24. SW10 can be in either position (it makes no difference when SB44 is cut). To restore normal kit operations (e.g. erasing & programming the SiP), put a jumper on the two uppermost pins of P24.

Kind Regards,

Bjørn

RE: Instructions for setting up 9160 DK for current measurement are confusing

Bjørn Kvaale — Thu, 17 Jan 2019 13:26:25 GMT

I have asked about this issue internally & will get back to you with an update.

RE: Instructions for setting up 9160 DK for current measurement are confusing

rkguy — Fri, 11 Jan 2019 04:52:51 GMT

It is also correct to say that any current measured at p24 is Vcc or Vin? If I am supplying 5V on p28 then am I measuring current at p24 with voltage of 5V?