Low Power Blinky Example - Power Consumption Problem - Power Profiler Kit II and nRF52840 DK

Question

Hello, 
 I have tried running Blinky example with some Low Power directives in the code without success. I came here for help then. 
 The current consumption used by the example, based on the Blinky sample, on the nRF52840 DK, stays around 2mA when the LED is off. 
 I am using NCS v2.1.0 and nRF52840 DK. I have used the Voltage Source meter mode for consumption measurement on the PPK II. 
 Here is the code: 
 4276.blinky.rar

Though the USB cable is connected to the DK in the image below, it is disconnected from the PC USB.

Hieu · Accepted Answer

Hi thiago_hd, 
 First, sorry I forgot to mention the SB40 setup. Since we are working on Power Profiling, I assume it is done already. That was a bad assumption. 
 thiago_hd said: Can you explain to me why I can only see the turn ON/OFF event of the LED, instead of it's current consumption during the time that the LED is ON? Is it because the current draw for the LED is coming from the USB port? 
 Yes, you are exactly right about that. The setup only measures the current drawn by the nRF chip. 
 thiago_hd said: Is there a way to change this so the LED will be fed by the PPK2? 
 
 On this note, are you going to have your custom board with only the nRF and an LED or are you going to use the DK as a temporary solution? 
 If you are using the DK as a temporary solution, then the setup we initially started with will measure exactly that. Just revert to it, remove the debugger USB, short the P22 pins together with a jumper to replace the broken SB40. 
 If you are having your custom board but would like to evaluate with the DK, I will need to check with someone experienced before I answer you. I will get to this on Monday. 
 Alternatively, the setup right now (described in our last replies) measures only the nRF chip. If your final product consisted of only the nRF chip and an LED, you could calculate the expected consumption of your LED and add to the current measurement of the nRF chip.

thiago_hd said: How can I reduce the current consumption even more? I wanted to achieve as little as 5 uA on average, during the time where everything is SUSPENDED. 
 
 There are a few resources I can recommend for you: 
 The following blog post discusses how to do it on nRF52 chips. Some points are detailed for the nRF5 SDK, but can be transferred over to nRF Connect SDK, or is covered in the next article. Optimizing Power on nRF52 Designs 
 The following blog post discusses how to do it on nRF53 chips. Again, the points can be transferred over to the nRF52840 development. Optimizing Power on nRF5340 SoC Designs 
 I think you will also use some wireless communication when you use Nordic Semi's products. If you use BLE, the Online Power Profiler tool is helpful to estimate current consumption changes as you tweak BLE parameters. It can be found here: opp 
 Here is the official guide on the nRF Connect SDK documentation. I think the blog posts above already included all ideas in this document though. Power optimization — nRF Connect SDK documentation 
 Finally, the entirety of DevZone is a resource. If you want to optimize some specific use case, just search and there might have been someone else who did it. This Q&A is a good example: nrf52 - PPI + EasyDMA Power Consumption 
 I feel a sense of urgency in your comments. Is there an urgent topic going on? I am unfortunately back in another backlog situation. It is difficult, but if something is urgent, please let me know and we will see what can be arranged. 
 Best regards, 
 Hieu

Low Power Blinky Example - Power Consumption Problem - Power Profiler Kit II and nRF52840 DK

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