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<\/p>\n\n\n\n
esp32_deep_sleep_start();<\/code><\/pre>\n\n\n\ntook 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.<\/p>\n\n\n\n
Trying various different cures recommended by various sites including Espressif’s own had little effect, until I stumbled across a Reddit post<\/a> 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.<\/p>\n\n\n\npinMode(4,OUTPUT); \r\n\rdigitalWrite(4,LOW); \/\/ Should force backlight off\r\n\rtft.writecommand(ST7789_DISPOFF);\/\/ Switch off the display\r\n\rtft.writecommand(ST7789_SLPIN);\/\/ Sleep the display driver<\/code><\/pre>\n\n\n\nThanks, Random Internet Person<\/a>!<\/p>\n","protected":false},"excerpt":{"rendered":"10mA isn’t an acceptable sleep current. Here’s how to put the TTGO to sleep. Continue reading