ESP8266 Community Forum

- Tue Jan 20, 2015 6:30 am #7786 So to finish off your initial data set, what is your chip ID and measured supply voltage?

And what sort of measurement device did you use? handheld multimeter? According to these people: http://www.robotroom.com/Multimeter-Reviews-5.html you maybe can't rely on the last mV level accuracy of many DMM's? If so it would be better to just give voltages to two decimal places, i.e. 10's of mV.

Unless you have a home lab like Shahriar


And if you think that's a lot of kit, you should see what he's got in the lab at work

- Tue Jan 20, 2015 6:55 am #7789 Sure I would not use this values for battery measurement - I selected them to achieve precise measurements. With 100K+ you will get errors because of the leakage current that might flow from the chip pin. But your note is right because somebody might try to use my values for battery monitoring!
My chip ID - I don't have it right now, I will check. Saying "chip id" I meant that each chip will have slight variations - so if somebody posts result from multiple chips than we have to know this.
I used a low-cost DMM, will check with professional Fluke tomorrow. My intension was to get preliminary measurements - and to prove if there is a dedicated reference voltage inside or not.
Hope that somebody will pick from here and move on ...

- Tue Jan 20, 2015 7:40 am #7794 Excellent if you have access to one of those yellow machines! Depending on the model, it might be 0.05% +1!!

Then we will be able to have confidence in the mV reading I suspect!

G

- Sat Nov 07, 2015 3:22 pm #33379 Ok clever people, here's something i'm scratching my head on -re using the ADC to read the internal voltage. At startup for between half a minute and 1.5 minute the readings start high around 4v before settling down to about 3.7v (supply is 3.3 from a AMS1117). I will try attaching the Thingspeak graph.... Oh and it's the ESP-12 (AL-THINKER)and nothing else is connected to that pin. (ignore the end of the graph) Any thoughts why this happens and how i can get good readings from startup?