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
pybl.jpg (131.57 KiB) Viewed 324 times

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 324 times

shaoziyang
Posts: 275
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 298 times
(series 10 Ohm resistor)

deepsleep power consumption
pybL-2.jpg
pybL-2.jpg (212.79 KiB) Viewed 323 times
pybL-4.jpg
pybL-4.jpg (186.74 KiB) Viewed 323 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

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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