Possible to publish the voltage from the screw terminal on the asset tracker v.2?


I am wondering if it is possible to get a voltage reading from the screw terminals on the asset tracker v.2? I would like to see remotely the voltage that the supply has.

Thank you in advance.

I don’t think so but you could easily add that feature by adding INA219 voltage current monitor to the mix.


Thank you for the reply!

I did a bit of research on this forum and found this posting (Voltage Monitoring) where you had also contributed but I could not discern see any wiring information. Would you mind giving me a bit of advise on the wiring of the unit? As I mentioned above I am looking to measure the voltage of the charging source for the asset tracker v.2.

Here is how I understand it after reviewing the Adafruit:

INA219 - Asset Tracker
Vcc - 5v
Gnd - Gnd
Scl - Analog pin
Sda - Analog pin
Vin- - Negative terminal
Vin+ - Postive terminal

Does this sound correct? My issue is that I only have one analog pin available. Is it possible to use C4 and C5 as they are both 12C communication pins?

Thank you in advance.

The SDA and SCL pins on the INA219 go to the SDA > Pin D0 & SCL > Pin D1 on the Photon.

There should be a library in the library list for this and if not I have one I can share that works with the Photon.

If you just want to measure voltage and not current then you just need to connect the RED and Black wires it shows coming from the battery pack. It can measure current but the way its setup it’s rated for 3 amps so if you have to tweak the settings if you want to measure more current than that, and I think it maxes out at 5 amps due to the traces on the board and the current sense resistor size.


Thank you for the quick reply!

Correct, I am only interested in the voltage. The supply is a 12v battery bank and should spike no higher than 14v from the battery charger. So if I may just repeat back to you what you’ve just told me so that I can be sure that I understand:

INA219 - Asset Tracker
Vcc - N/A?
Gnd - N/A?
Scl - D1
Sda - D0
Vin- (pin, not screw terminal) - Negative screw terminal
Vin+ (pin, not screw terminal) - Postive screw terminal

If you wouldn’t mind sharing the code I would be most grateful! I’m by no means a coding guru.

Thank you!

Vcc = 3.3v
Gnd = Gnd
Vin+ goes to your battery + terminal.
Vin- = Not used since you’re not measuring current flow.

Fuse that line in your permanent install with a 1 amp fuse between the battery and Vin+ on the INA219 board just to be safe.

Here is the INA219 Library: https://go.particle.io/shared_apps/59baab1408187b00210015ce

1 Like


Thank you very much!


1 Like