Justin Richards gmail.com> writes: >=20 > "V Actual" was the data in the left column. It was the voltage that was > set using the Fluke. I should have perhaps used more digits to indicate > precision. > "V ADC" the data in the right column was then read from the ESP8266. I ha= d > it set to print the ADC every second. The value jumped around a little so= I > tried to average the value. The bit that doesn't make sense is that an ADC does not spit out a voltage, rather you get a binary code word. To get a voltage, you must have already made some assumptions about the ADC reference voltage and transfer function= , and making these assumptions before measuring the actual performance is somewhat pointless. You should be plotting the ADC code word against voltage, and from that you can measure the offset and gain errors, and if you have enough points you could also measure INL and DNL performance. However, as someone else suggested, your measurement device must have substantially better performance than the ADC to get useful results. Isn't the Fluke 87 a 6000 count device? If so it's not really adequate to fully characterise a 4096 count ADC though gain and offset error measurement should be ok. Also note that all ADCs will have some spread of offset and gain errors, so there is no guarantee that someone else's ESP12 will give the same performance as yours. I've not used the ESP device yet, are the ADC specifications not published? Regards Mike --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .