ESP8266 Community Forum

- Fri Jan 08, 2016 1:14 pm #38222 Hi guys,

I'm trying to understand if anything is wrong with my code. I have an OLED display wired, but when I try to save some power and send SSD1306 the DISPLAY_OFF command, 2 things happen:

• The comms LED on ESP8266 is constantly lit (odd, see here https://youtu.be/mdC_2jkhn_g?t=14s )
• The power draw doesn't drop - the USB detector device still shows 20mA no matter whether display is on or off

Here's how I turn the display off: https://github.com/aperepel/iot-esp8266 ... n.ino#L172
Any pointers or ideas?

- Sat Jan 09, 2016 9:35 am #38297 I moved the SDA pin from D2 to D7 which took care of LED side-effect. The power draw stays constant, though.

- Sun Jan 10, 2016 5:28 pm #38455 Hi Andrew Grande !

for a real 'display off' (6µA in my case ) you have to deal with chargepump (SSD1306 datasheet, fig 8-16 and 8-17)
'displayoff ' then chargepump off

Code: Select all  display.sendCommand(DISPLAYOFF);
  display.sendCommand(CHARGEPUMP);
  display.sendCommand(0x10);

and then for display on : charge pump on, then 'display on'

Code: Select all  display.sendCommand(CHARGEPUMP);
  display.sendCommand(0x14);
  display.sendCommand(DISPLAYON);