ESP8266 Community Forum

- Fri Jun 02, 2017 2:05 am #66631 Hello everyone,

I hope someone can help me as I am out of ideas. I have a NodeMCU board which I want to connect to an Air Quality sensor (CCS811) from sparkfun. I connected the sensor's SDA and SCL to pins D2 and D1 respectively, but when I compile the "Basic Readings" sample code provided with the CCS811 library (https://learn.sparkfun.com/tutorials/cc ... 1492205268) I get an error after uploading the code:

Z+�I$��9r��CCS811 Basic Example
.begin() returned with an error.

Soft WDT reset

ctx: cont
sp: 3ffef2b0 end: 3ffef490 offset: 01b0

>>>stack>>>
3ffef460: 3fffdad0 00000000 3ffee440 402020ac
3ffef470: feefeffe feefeffe 3ffee45c 40202cb8
3ffef480: feefeffe feefeffe 3ffee470 40100114
<<<stack<<<

Can someone please help me out? I tried running the code in an Arduino Nano and it ran perfectly, so my only guess is that the code is not reading the SDA, SCL signals from the D1/D2 pins, but I don't know where I could change this.

Any help is appreciated.

- Sun Jun 04, 2017 2:17 pm #66721 Same problem here, let me know if you find a solution. I use my own sketch (no library) and I'm able to read from sensor's register basic informations about sensor (STATUS,HW_ID,HW_VERSION...) but when I try to switch to app mode by

Code: Select allWire.beginTransmission(CCS811_ADDR);
Wire.write(APP_START);  //0xF4
Wire.endTransmission();

ESP8266 (I use Wemos D1 Pro) goes to soft reset (the same issue as you have)...
I use combo sensor CJMCU-8118 with HDC1080 humidity/thermometer. The second sensor on the board works fine without issues. Also no issues with both sensors on Arduino Uno.

- Tue Oct 24, 2017 6:30 am #71163 Are you sure you have connected the wake wire properly? (i connected it to the ground on my nodemcu). its stated to not be required but worth a try.

Petre:how did you get the temp and humidity from this combo board please?

I also have a strange problem. after a while (random interval between 1 minute to 1 hour) i start getting the same error, soft wdt reset. failed to start the sensor. i need to either reset the board or disconnect and reconnect the power to bring it back to life. have you guys faced this issue?

- Tue Oct 24, 2017 7:12 am #71167 BTW jorgeg922 try ada fruit library instead of the spartfun.

https://learn.adafruit.com/adafruit-ccs ... r?view=all

also can you let me know how you got temp and humidity working?i have asked Petr also.