Ten milliamps doesn’t sound like a lot — but for sleep/standby mode, it is. A recent project was intended for occasional use as a desk toy, and would spend most of its time sleeping. Running the recommended
esp32_deep_sleep_start();took the current from ~70mA with the system running at full speed with the display on, to ~10mA. That’s over an 80% savings, but would still drain the gadget’s 1000mAh battery in just a few days.
Trying various different cures recommended by various sites including Espressif’s own had little effect, until I stumbled across a Reddit post by [infuriatingPixels]. The following four lines of code took the project’s power consumption from ~10mA to ~380uA in standby — a more than 20x additional savings. And it can still do wake-on-touch.
pinMode(4,OUTPUT);
digitalWrite(4,LOW); // Should force backlight off
tft.writecommand(ST7789_DISPOFF);// Switch off the display
tft.writecommand(ST7789_SLPIN);// Sleep the display driver