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stuartpittaway / diyBMSv4ESP32

diyBMS v4 code for the ESP32 and new controller hardware
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Suggestion: reduce ESP32 clock frequency #140

Open laserranger3000 opened 2 years ago

laserranger3000 commented 2 years ago

The CPU frequency could be reduced to save power. Especially for (my) offgrid application where there is sometimes no charge current for months, the self-discharge due to the controller consumption becomes significant. I've added this line to the platformio.ini and saw a current decrease of the controller on 5v from about 200mA to 170mA: board_build.f_cpu = 80000000L Even lower frequencies didn't work in the platformio environment, but should be technically possible. Another idea would be a function to disable the wifi radio. Maybe controlled by a switch connected to the external IO ports.

stuartpittaway commented 2 years ago

Good idea, would have to check the CPU still performs okay with the reduced speed.

This probably links into #120 perhaps we could use one of the buttons on the controller to "wake" up WIFI?

laserranger3000 commented 2 years ago

At 80 Mhz I didn't notice any negative impacts on the functionality or web-interface performance.

Yes, a button to wake up wifi would be awesome. It could go back to "sleep" after 30 minutes or so (should be enough time to check the status and change settings)

pkathey commented 2 years ago

+1 for either functionality/button to disable/sleep wifi OR (preferably) introducing an A P mode that is only enabled when it's needed. After looking at latest iteration of the controller board I see it wont be possible to simply retrofit an older controller (like mine) with switches so it looks like there is no choice but to upgrade the board ...otherwise neither sleep nor disable option will be possible anyway.

laserranger3000 commented 2 years ago

I was playing around in the code a bit, but I don't fully understand how it works yet... To disable the wifi after a few minutes I tried to call this function with a timer in void loop() (including the library): WiFi.mode(WIFI_OFF); But it doesn't do anything. The only way I could disable Wifi at all was to disable this function in void setup(); wifi_init_sta();

Can you give me a hint where I should edit the code to dynamically enable/disable wifi? is it even straightforward?

By the way, I'm down to 50mA with 80 Mhz clock speed and disabled wifi, it's promising :)