Unable to connect to the PPK

RE: Unable to connect to the PPK

Sigurd — Mon, 04 Sep 2017 12:32:09 GMT

Hi,

Could you test the suggestions that is given in this post?

RE: Unable to connect to the PPK

Sigurd — Mon, 28 Aug 2017 07:49:16 GMT

but still got current around 50 mA. This occurs only after around 30 seconds. I have a low current in the beginning.

This is exactly 30 seconds? and does this always happens after 30 seconds?

RE: Unable to connect to the PPK

Sigurd — Thu, 24 Aug 2017 16:56:54 GMT

I realised that both boards have to be USB connected

Actually, only the nRF52-DK needs to be be connected with USB. See figure 9, page 15 in the PPK user guide.

The PPK supports two modes of operation:

Current measurements on the nRF5x DK device
Power supply and current measurements on an external board

When doing measurements on the nRF52-DK, the DUT needs to be set in off mode. In your first image(PC) you have DUT Onand are therefore only measuring noise. In the image for the MAC, you have correctly set the DUT in DUT Off. Your measurement that shows 52mA is extremely unrealistic, so there is something that is not correctly set-up.

RE: Unable to connect to the PPK

Bernard Perrin — Thu, 24 Aug 2017 14:25:48 GMT

Hi,

thanks for your reply. The nRF52 DK SB9 has been cut. From your remark I realised that both boards have to be USB connected. I was stupidly assuming that PPK power the DK so USB is not necessary for this board. Once both connected, I can start the program but I get strange results. I tried with the Mac/VmWare/Win7 and a PC/Win8 (see annexed pictures). Results are very different but could be similar at a different moment. They correspond to a connected device via BLE with a connection event period of 30 ms. When I close the connection, the device return in advertising mode with a 100 ms period. However, nothing change in the consumption.

What should I do to get better results?

PC:

Mac:

Thanks for your comment concerning "DUT On/Off". So I used DUT Off on the PC/Win8 (the supported platform) but still got current around 50 mA. This occurs only after around 30 seconds. I have a low current in the beginning. However, the application works all along, connected to an iPad, and periodically communicating with a connection event period of 30 ms.

SB9, SB11 & SB12 are not soldered.

What could be wrong with my config?

Today it seems to be repeatedly around 10 seconds. The first 10 seconds the current is very low (below a noise of +-600nA). The 10 seconds are measured after the calibrating pop-up window disappeared. Then, the current has an average value of 52.5mA, a max of 55 mA. Closing the connection with the iPad (so turning the device in advertising) doesn't change anything.

The measured values with a resistor (10.6Ω) are much better understandable:

One can see the 3 pulses for the 3 advertising channels and an OS kernel activity each ms. The advertising average current is 7.2 mA for a duration of 2.6 ms. This is very different to the 50mA measured by the PPK.

If I click Stop, it takes around 1 minutes for the display to stop (same for trigger). The trigger level seems to be useless: if I set the trigger to a very high level (1000000µA=1A), the display still updates with values between 51 and 55 mA.

RE: Unable to connect to the PPK

Sigurd — Thu, 24 Aug 2017 11:43:25 GMT

Hi,

Are you able to detect the nRF52-DK(PCA10040)? Try nrfjprog -i to list the serial number of the debuggers connected to the PC.

Also make sure that the SB9 solder-bridge on the nRF52-DK is cut when using the PPK. From Chapter 2 in the PPK user guide:

If the PPK is used with the nRF5x DK, prepare the nRF5x DK for power measurements by cutting the PCB track shorting solder bridge SB9 according to Preparing the development kit board. Do not short the solder bridge SB11/SB12.