Schorschi asked 6 years ago Using several ESP8266s in testing, this is driving me nuts, I have a BME280 on i2c (D3,D4) it works great. Then I added 3 LEDs driven by D5, D6 and D7. If don’t initialize D5, D6 and D7 for digital output, i.e. to turn the LEDs on and off, the BME280 is fine. But once I set any of the D5, D6, and/or D7 pins to output, the BME280 starts generating junk data, invalid temp, humidity and pressure readings. I have done this on other microcontrollers, even on Pi devices without issue. The power is solid at 3v via USB or separate supply. So at a loss why this is happening, it really does seem like a power issue, but need some help to figure out why. I do not have any resistors on the LEDs, they function at 3v without issue. I tried moving LEDs to other pins but no success, same result.