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Xinyuan-LilyGO / LilyGo-LoRa-Series

LILYGO LoRa Series examples
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No 3.3v power when running on battery? #15

Closed nebukadnezar closed 3 years ago

nebukadnezar commented 4 years ago

I'm trying to power a SSD1306 display from the 3.3v supply. Power management is started as follows:

  axp.setPowerOutPut(AXP192_LDO2, AXP202_ON);
  axp.setPowerOutPut(AXP192_LDO3, AXP202_ON);
  axp.setPowerOutPut(AXP192_DCDC2, AXP202_ON);
  axp.setPowerOutPut(AXP192_EXTEN, AXP202_ON);
  axp.setPowerOutPut(AXP192_DCDC1, AXP202_ON);

  axp.setDCDC1Voltage(3300);

This correctly sets the 3.3v supply (which was 1.8v before using setDCDC1(3300)) - but only when USB is connected.

How do I enable this while running on battery?

My TTGO version is T22 V1.0

lewisxhe commented 4 years ago

It only needs to be set once. This setting is regardless of whether it is battery-powered or USB-powered.

nebukadnezar commented 4 years ago

Yes, I'm only setting the power settings in the startup. But can you tell me which parameter I need to set so the 3.3v points has power when on battery? All 3.3v power points show 0.0v when running on battery, and only when USB is plugged in do they show 3.3v.

lewisxhe commented 4 years ago

You only need to set the following two lines, it can turn on the power axp.setPowerOutPut (AXP192_DCDC1, AXP202_ON); axp.setDCDC1Voltage (3300);

nebukadnezar commented 4 years ago

Well, that was user error on my part! After inserting the battery, it helps to push the power button to turn the TTGO on... Can be closed as fixed. The axp functions work as described.