MicroPython Forum (Archive)

I have made new ultra low power consumption pybL board.

feature

• STM32L476RG microcontroller
• USB type-c
• Ultra Low Power Consumption with current test interface
• optional SPI flash

running power consumption
(series 10 Ohm resistor)

deepsleep power consumption

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?

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

In running mode, it about 10mA.

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

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

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).

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

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).

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