ATOMS3 Screen Backlight → Want to Switch OFF

hugo.reed

Hello Here,
In order to only use my AtomS3 for a BLE application and connect it via USB-C to a small battery, I'd like to cut the backlight completely in order to save energy and tiny heat when long time ON, ∆ and also use an OTII-ARC tool to measure the consumption of my program and the AtomS3 in this BLE advertising mode,

without over-consumption due to the fact that the backlight is always ON - even if the pixels are black.
I understand that the lcd is a N085-1212TBWIG06-C08 ; on the M5STICK and M5STICKplus I was able to cut the screen with the following code: (thanks community)

*void turnOffScreen() {
// try to turn off screen - https://community.m5stack.com/topic/1025/m5stickc-turn-off-screen-completely/11
// OK
Wire1.beginTransmission(0x34);
Wire1.write(0x12);
Wire1.write(0b01001011); // LDO2, aka OLED_VDD, off
Wire1.endTransmission();

// not tested
/M5.begin(0,1,1);
M5.Axp.SetLDO2(false);
M5.Axp.SetLDO3(false);/

//M5.Lcd.setBrightness(0);
//M5.Axp.ScreenSwitch(false);
}*

The reason I'm here is that this code doesn't work on the ATOMS3 and I haven't figured out how to do it yet.
Can you help me?
Thank you in advance

Tyler

felmue

Hello @hugo-reed

according to the M5AtomS3 documentation the backlight is connected to GPIO16. So setting that to LOW should turn it off. (Note: not tested)

digitalWrite(16, LOW);

Note: GPIO16 gets initialized and set to HIGH in function M5Display::begin().

Thanks
Felix

frameworklabs

Alternatively - using M5Unified you can also call:

M5.Display.sleep();

To wake it up again use:

M5.Display.wakeup();