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m5stack / M5StickCPlus2

MIT License
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[HW] More power saving #7

Open matsujirushi opened 1 week ago

matsujirushi commented 1 week ago

I discussed with @lovyan03 -san. Thank you!!

I am trying to create software that can operate for a long period of time on battery operation. We want to reduce battery consumption in standby mode as much as possible, and have implemented the following methods.

Method 1:

Wake up using RTC. Power consumption is low enough because the main power supply is turned off. (40 µA)

This method is very good for reducing power. However, the ESP32 power is completely turned off. Therefore, the prelocation must use flash ROM to record the status, which increases the number of ROM writes and becomes burdensome.

Method 2:

Keeps ESP32 in DeepSleep state. Power consumption is higher than Method 1 because the main power is turned on. (1mA) This method places no burden on ROM because the RTC_ATTR area can be used for application state recording. However, power consumption is high and we would like to reduce it more.

Feature request:

Turning off 5V DCDC (U6) halves power consumption. (410uA) (Remove the R22 register.) However, the POWER button will not function.

  1. I would like to be able to use the POWER button even when 5V DCDC is turned off.
  2. I would like to be able to turn on/off 5V DCDC from ESP32.