low power consumption pbyL board

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shaoziyang
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Joined: Sun Apr 17, 2016 1:55 pm

low power consumption pbyL board

Post by shaoziyang » Thu Aug 29, 2019 4:37 am

I have made new ultra low power consumption pybL board.
pybl.jpg
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feature
  • STM32L476RG microcontroller
  • USB type-c
  • Ultra Low Power Consumption with current test interface
  • optional SPI flash
pybL-pins.png
pybL-pins.png (145.55 KiB) Viewed 4640 times

shaoziyang
Posts: 363
Joined: Sun Apr 17, 2016 1:55 pm

Re: low power consumption pbyL board

Post by shaoziyang » Thu Aug 29, 2019 4:44 am

running power consumption
pybL-1.jpg
pybL-1.jpg (185.21 KiB) Viewed 4614 times
(series 10 Ohm resistor)

deepsleep power consumption
pybL-2.jpg
pybL-2.jpg (212.79 KiB) Viewed 4639 times
pybL-4.jpg
pybL-4.jpg (186.74 KiB) Viewed 4639 times
Last edited by shaoziyang on Thu Aug 29, 2019 2:59 pm, edited 1 time in total.

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pythoncoder
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Re: low power consumption pbyL board

Post by pythoncoder » Thu Aug 29, 2019 7:28 am

Deep sleep current is amzing, but the "running power consumption" picture doesn't seem to tell us much. What sort of figure is achievable running MicroPython?
Peter Hinch
Index to my micropython libraries.

shaoziyang
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Re: low power consumption pbyL board

Post by shaoziyang » Thu Aug 29, 2019 3:19 pm

I am sorry to put the wrong picture, I have fixed it.

In running mode, it about 10mA.

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Roberthh
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Re: low power consumption pbyL board

Post by Roberthh » Thu Aug 29, 2019 3:49 pm

Do youi also use the 10 Ohm shunt resistor in the current test for sleep mode?

shaoziyang
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Re: low power consumption pbyL board

Post by shaoziyang » Fri Aug 30, 2019 1:10 am

Yes, it will make the display data a little smaller.

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Roberthh
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Re: low power consumption pbyL board

Post by Roberthh » Fri Aug 30, 2019 6:49 am

If I understand the properties of your multimeter right, the internal shunt for the µA range is 1000 Ohm (199.99mV/199.99µA). With the external shunt of 10 Ohm this means, that only about 1% of the current goes through the multimeter. So instead of the shown ~10nA, the devices consumes about 1 µA. That matches the data sheet of the STM32L476RG microcontroller, and is still an excellent value ( ~23 years standby on a 200mAh battery, if only the battery would last that long).

shaoziyang
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Re: low power consumption pbyL board

Post by shaoziyang » Fri Aug 30, 2019 1:55 pm

I use ZT303, a 4 1/2 bits multimeter. Internal shunt for uA is about 100 ohm, not 1000 ohm.

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Roberthh
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Re: low power consumption pbyL board

Post by Roberthh » Fri Aug 30, 2019 2:03 pm

Then the current has to be corrected by a factor of 11. When the meter shows 90 nA, the actual current is ~1 µA. (In my previous post I read the meter wrong as ~10nA).

shaoziyang
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Re: low power consumption pbyL board

Post by shaoziyang » Sat Aug 31, 2019 10:19 am

Current firmware is not reach the minimum power consumption of STM32L476, but its power consumption is low enough for most battery-powered applications.

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