What is lowest consumption of D-series?

[eradicatore]

Hi,
I see this nice chart of the pyboard v1.1 here:

https://store.micropython.org/pyb-features

which gives power consumption data. I can't seem to find anything on the d-series though? There is some mention of 50uA in the command sheet here but I feel that's out of date perhaps and more just general info? See pyb.standby()

https://docs.micropython.org/en/latest/library/pyb.html

What's the lowest power anyone has gotten a pyboard d-series down to?

Thanks!!
Justin

[pythoncoder]

Sub 50μA is definitely possible on Pyboard 1.x. I believe the Pyboard D is capable of this but haven't tested it. You'll need to disable USB and WiFi and possibly the 3.3V output regulator. For the very lowest power consumption it's best to put unused pins into output mode (floating inputs can draw power).

I used pyb.stop() successfully on the Pyboard D until this issue cropped up which has paused my work on this.

[eradicatore]

Ok, thanks. I have a 1.1 pyboard, but wanted to create a low power device that had the ability to "check in" periodically with wifi so I was very interested in knowing how low it can go. I was surprised they published specs directly on low power for 1.1, but not the d-series. I think I'll order one to play with then. I haven't looked at the commands to stop usb and wifi, so I'll do that now.

Thanks for the warning on the issue you were hitting!

[pythoncoder]

Low power usage is promised for the Pyboard D. The developers are currently working on other promised features such as BLE.

@Damien has written a demo of a webserver running at very low power levels so the hardware has this capability. I'm sure the issue with pyb.stop will be fixed in a future firmware build. Hopefully characterisation, demos and documentation for low power modes will arrive before too long.
[EDIT]The issue with pyb.stop is now fixed.

[Damien]

When developing the pyboard D-series we did a lot of low-power measurements and optimisations, because it was a key goal to obtain optimal lowspower operation of the MCU and WiFi chips.

Not all low-power features are available yet, nor all characterised, but to give you an idea:

• in lowest power mode, machine.deepsleep() (=pyb.standby()) with reset on wake, it gets down to about 10uA
• with full RAM retention sleep, machine.lightsleep() (=pyb.stop()), resume on wake, it gets down to about 200-300uA
• with WiFi STA connected to an access point with large DTIM and no WiFi traffic, machine.lightsleep() can get down to around 500uA average in optimal conditions

[eradicatore]

Excellent!! I'm sold, I'm ordering as we speak.