ESP8622 current measurement with the uCurrent - Burden Voltage Trap?

[Zh4ng]

Hello everybody,
I would like to measure the power consumption of a ESP8622 in Sleep mode. But I think the Burden Voltage makes life difficult for me.

I use Dave's uCurrent. In mA range everything is OK, but the uA range I have a voltage drop of 3.3V to 1.9V and the circuit hangs.

Am I correct? or am I doing something wrong?

I think I went into the trap as a young player ....    btw. i am a young player.... 

Thx for help

Zh4ng

[zapta]

Will connecting a diode in parallel to the input  help? It will conduct in the wake state but will give reasonably accurate reading in the sleep state.

[borjam]

What about using a power supply with sensing inputs? I just got an AIM-TTI EL302R. I imagine that connecting the sensing after the point where I have inserted the µCurrent would help.

Or is it just the syndrom of the brand new toy?

[zapta]

If you use the sense approach, you need to make sure that the input current of the sense input is negligible.

[borjam]

Anyway I must do it and I purchased a µCurrent a month ago for that purpose, so I will let you know how it goes.

[wraper]

Shunt resistance in uA range is 10 ohms. No wonder it shuts down. You are exceeding the current rating at this range by more than 100 times.  If you are desperate to use uA range, then short uCuttent's input terminals together then start the thing, put into the sleep. Remove the jumper wire between the terminals, measure. Or get higher resolution multimeter if current resolution is not enough and measure in mA range.

3 Current ranges:
+/- 0-1250mA (20µV / mA burden voltage typical) * switch contact resistance plays a role here. 10uV due to the shunt resistor.
+/- 0-1250µA (10µV / uA burden voltage)
+/- 0-1250nA (10µV / nA burden voltage)

[Zh4ng]

Shunt resistance in uA range is 10 ohms. No wonder it shuts down. You are exceeding the current rating at this range by more than 100 times.  If you are desperate to use uA range, then short uCuttent's input terminals together then start the thing, put into the sleep. Remove the jumper wire between the terminals, measure. Or get higher resolution multimeter if current resolution is not enough and measure in mA range.

3 Current ranges:
+/- 0-1250mA (20µV / mA burden voltage typical) * switch contact resistance plays a role here. 10uV due to the shunt resistor.
+/- 0-1250µA (10µV / uA burden voltage)
+/- 0-1250nA (10µV / nA burden voltage)

Ah ok,
then my first guess is correct. Thanks for the tip. 

I use a 34401A.

I'm going to jump a little in the rabbit hole ..... 

[borjam]

As I said, I am on the same bandwagon now and, given the enormous difference in power consumption between WiFi activity and deep sleep, I intend to do it in phases. I mean: how much does it take when deep sleeping? How much energy does this sensor reading routine use? How much when transmitting via WiFI?

With all that, and measuring the energy usage of the different routines I can have a nice estimate of energy needs for a battery powered sensor and actually find out wether it's doable with an ESP8266 or not.