That's what i want to explain.
it is mostly the measured value and not the calculated value. so it cannot be the input voltage and an 100nF won't do anything unless it is at the input of the buffer
must be software but will replace the ESP8266, maybe an micro issue.

in addition attached a picture of Domoticz temperature of the central heating radiator. temperature is going from eg 20 degrees to 383.
As you can see a normal cooling down of a radiator if you ignore the scale.

Thanks, indeed a typo, the sensor is connected via a buffer opamp directly connected to ESP8266 ADC input. Voltage are verified with an oscilloscope (Tektronic ) no spike whats so ever. besides that. if so then you can't have one moment 377 and next moment 19 these two values are pretty close to the...

hello all, i am using a the ADC of Espeasy Esp8266 to measure the temperature (TMP37 20mv/C) full scale is 1024= 1v which means in my case that i need to divide the ADC value by 19 According helppage i can do this by using %valu%/19 at the bottom of the Devices / task settings / values. Problem: som...

@ budman,
ds18b20 works within 0,5 % on a 1-wire maxim dev kit compared to a digital precision temp meter.
ds18b20 has an 5 degrees diff with the above on a esp8266.

@ td
thanks will try

thanks Shardan but i have measured all ds18b20 with a original maxim 1-wire evaluation board and all are within 0.5% also it is not possible to heat it up by means of applied power. the whole circuit draws less then 2mA @3v3. and the sensor is glued into a 5mm thick housing. @ TD-er where can i find...

hello all, question i have seen before on the forum but no satisfying answer. the ds1820 gives a 5 degrees higher temperature then it should. i have tried differed esp8266 (build 120) and different ds18b20 sensors and different pull ups at different Gpio's. but the result stays the same. The 1-wire ...