Volatile current readings from NodeMCU vs Wemos D1 Mini

ESPHome
1

Good Day,

Apologies upfront if this is the wrong forum, I built a power meter using this cct (from Mottram labs):

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I built it myself as the time to order the component would be too much (South Africa) and it might be a bit more expensive, I use Wemos D1 for the first device and NodeMCU for the second device. I use esphome to upload both sketches and the calibration values are similar. The problem I have is that the NodeMCU one is way too volatile, I’ve tested with two nodeMCUs and still get volatility. I am measuring my fridge power. Is there a way to reduce this volatility, it looks like the two have a similar average (see below):

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I used a known load (kettle) and a regular ammeter to calibrate both. I would appreciate any assistance for reigning the volatility in.

Aside: I was forced to use the MQTT component in esphome for the nodemcu version as the readings were not coming through regulalrly with the api: , the mqtt stream is more reliable .

Regards
Caswell

2

ESP32 or 8266?

The ESP32 ADC has a selectable voltage range depending on the attenuation option, Analog To Digital Sensor — ESPHome

Also see the note above that about the D1 resistor multiplier.

3

Thank you, it is a nodemcu esp8266, the stabler one is the wemos d1 mini.

4

So the D1 reports 0-1v for a 0-3.3v input due to the physical input voltage divider. Does your nodemcu have this and what voltage range are you feeding it?

5

According to the documentation of the nodemcu, they also have that 220k, 100k voltage divider, The voltage range being fed is 0 - 3.3V as the input to adc is hoked up to 3.3V as per the cct posed in initial post.