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Xinyuan-LilyGO / TTGO-T-Display

MIT License
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Powering off #62

Open oculos opened 3 years ago

oculos commented 3 years ago

Hi,

I wonder if there's a combination (like connecting EN to GND) to disable the 3.3V regulator and turn the TTGO off. I know I could use deep sleep, but I'd rather cut all power from the device. Is that possible?

Does the TTGO have a EN pin?

tadam777 commented 3 years ago

If you power from USB, there will always be power on the 3.3V But I assume you're on battery, did you try the PWR_EN pin ?

Its role isn't completely clear to me, but it looks like it commands a connection between the battery and the V3V pin (which isn't the VDD3V3 pin). This pin powers the USB chip, and some pull-up resistors. Is it a way to reduce the power consumption when the ESP32 is itself in sleep mode ?

image

T1j3ff commented 2 years ago

Set PWR_EN to 1 enable the battery voltage reading , but is consume a little tiny bit of power. It does nothing to power off the device

tadam777 commented 2 years ago

Yes, it's at least 50µA through R27 (and maybe as much through R28), which can seem very low, but it's relatively high in comparison to the ESP32 sleep modes (deep sleep 10µA, hibernation 2.5µA).

T1j3ff commented 2 years ago

And It does power the "BAT" pin , And BAT power R6/R7 And these alow the Voltage Reading image In the same order off magnitude of power loss

Pretty convoluted , but efficient