Hello everyone,
I don't have much experience on the electronics side nor the integrated circuits, so I need some advice. I want to measure a very small current with the help of Arduino, the voltage is 5V, and the current I measured with the multimeter is 0-40mA.So as a conclusion I would like a milliampere meter.
Can you recommend me a module or a scheme to be able to achieve this, I tried with an lm317 and a shunt resistance, but I do not do too well.
Thanks in advance everyone!
What is generating the input current ?
A 50 Ω resistor will give you 0-2v
0 mA? How low current you want to measure What precision? How much voltage you may drop on a shunt resistor?
Hello xrp12
Take a view to get some ideas.
LM317 - (https://www.ti.com/lit/gpn/lm317) - a voltage regulator?
We need a LOT more information to give useful answers. Firstly a schematic showing the system in which you wish to measure current. Is the current flowing in a gounded circuit? Is it DC or AC? What controls the current?
How much voltage loss is acceptable? (Measuring current without introducing a voltage loss is tricky)
Run it through an electromagnet and Hall sense the field should work.
Faraday/Lenz has no voltage term.
Hello and sorry for this late answer, I had some problems with the internet connection in my area.
Thank you all for your support and apologies for the brief information.
DC current
https://lucid.app/lucidchart/c1689dd5-70a0-4bd3-ab6f-35452c8a9579/edit?invitationId=inv_29c1219f-542e-44d1-a4bb-a4cf316603b1
I made here a schematic to be more explicit in which Rx is the resistance I want to measure(0-40mA [precision 1mA]) and the BlackBox refers to the set of other components that I need to make this measurement.A0 is the analog arduino pin.I would like to point out that I dont have much experience in electronic domain, so thank you very much for your help!
The Arduino A/D is really not ideal for precision measurement of low voltages across a very small shunt resistance.
Were I doing this project, I would use a sensor similar to:
INA219 High Side DC Current Sensor Breakout - 26V ±3.2A Max [STEMMA QT] : ID 904 : $9.95 : Adafruit Industries, Unique & fun DIY electronics and kits
This breakout board will solve all your power-monitoring problems. Instead of struggling with two multimeters, you can just use the handy INA219B chip on this breakout to both measure both the high side voltage and DC current draw over I2C with 1% precision.
With the internal gain set at the minimum of div8, the max current is ±400mA and the resolution is 0.1mA.
I cant see your schematic.
Without this we cant see if high side or low side sensing would be suitable.
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