electronic switch to control battery from Espruino GPIO

i thought when using the VBAT pin i get the (raw) battery voltage from BAT_IN? i uploaded a picture to show what i mean

Therfore, when powering up espruino and initializing AND before
powering down the display,, these pins have all to be set input float
("input"). Only AFTER display is powered up, pins and communication -
SPI - can be initialized and set.

thanks, that explained some weird behaviour

anyways it seems i found the cause for the root problem, i am using an e-paper display (SSD1606 controller with GDE021A1 display), but in a convenient ready-to-use module, which includes all the needed stuff (capacitors, etc.) for a proper working SSD1606 controller

well this module draws up to 25 mA current (at least that is what my multimeter showed me), it really works perfectly when driven by VBAT (e.g. CR2032 or 2x AA eneloops)

ok now i could use more pins like @allObjects proposed, but i will need a lot of pins for the final project (DCF77, e-paper display, maybe bluetooth BLE), i will find out if that is possible with one CR2032 :-)

the topic for electronic switches seems to be quite complicated so i take my time and start learning, i will try it with a mosfet

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