nRF5340 Tickless Idle

[jvr]

Hi

I'm currently evaluating the possibility of using nRF5340 in an upcoming project. As the chip is very new it's easy to understand that all specifications are not yet available. What I'm interested is the current / power consumption in tickless sleep. I would like to measure that using nRF5340-PDK (which I already have). I would need to have resolution of about 1 ms (1/1024 is fine).

I (eventually) did manage to get Zephyr toolchain and Segger Embedded Studio installed on Windows as per instructions, but couldn't figure out how to enable tickless idle. I could only reach current consumption of 1.65 mA (measured from P22, powered with coin cell, as instructed in the ). Curiously the current consumption doesn't seem to be at all by LED duty cycle or sleep time, nor 'nrf only' switch. I've been working on the 'blinky' example.

Is tickless idle supported yet?

Would you happen to have some sample project that I could try? I'm sure you have tested this many times already.

Thanks
Juho

[Håkon Alseth]

Hi Juho,

 

If you send me a direct message, with your address + phone number, I'll try to get a replacement kit sent to you.

 

Kind regards,

Håkon

[jvr]

Hi

Thanks, much appreciated. PM sent.

By the way, it's very nice that you create and make available development kits like this even if they don't have complete software support, or if they have some hardware glitches. They do provide very valuable insight to the new product even if they are not perfect (and in R&D, things rarely are anyway).

Juho

[Håkon Alseth]

Hi Juho,

 

jvr said:

By the way, it's very nice that you create and make available development kits like this even if they don't have complete software support, or if they have some hardware glitches. They do provide very valuable insight to the new product even if they are not perfect (and in R&D, things rarely are anyway).

Thank you for the feedback. This is what we're aiming for. Trying to get you acquainted with the hardware as early as possible, so that you're able to look at other aspects than just the application firmware (hardware development, basic evaluation and testing, PC software etc).

PS: The replacement kit was sent on friday, last week. Could you let me know if it does not arrive within this week?

 

Kind regards,

Håkon 

[jvr]

Hi

I just got the new PDK. Thanks!

Bad news though, the board seems to behave pretty much the same as the other 1.7 mA board. I made the same modifications and did the same recovery operation a few times before programming the blinky example. I even tried cleaning the board with IPA, no effect. This PDK is number 44-19-996 for what it's worth.

Could you build a "known good" binary and share it here (or PM)? I think it would be best to rule out software-related problems (who knows if there's some tiny difference in the source or toolchain somewhere...). I've attached my built binary and binary read from PDK after flashing.

Another thing to check would be whether the firmware on embedded j-Link is (emStudio asks to update it which I allowed for the newest PDK). Although I guess it shouldn't matter if "nRF ONLY" mode is used (it doesn't seem to make any difference).

Juho

3157.blinky.zip

blinky_flash.zip

[Håkon Alseth]

Hi,

 

I have used the ncs/zephyr/samples/basic/blinky untouched at my end. I tested your binaries, and my kit goes into low power mode.

However; I have been debugging a bit. It seems that the nRESET signal is present (set high from external logic, the segger IC), even if you disconnect the jumper from "nRF current measurement".

This will then try to reverse-power up the nRF, and I believe this is the reason why some of your kits are misbehaving. I cut SB42 (located above the "IF BOOT/RESET" switch) and got promising results after that.

 

Could you try this and see if that works better?

 

Kind regards,

Håkon