# How can I measure the current, in a precise way, using an arduino? [closed]

I designed a low noise current source for a project in my university and I would like to know if it is possible to measure the provided current using an arduino and a LCD.

• Use something like an ACS712 in addition. Commented Jan 24, 2018 at 9:46
• I would like to know if it is possible ... . Yes, it's possible. Commented Jan 24, 2018 at 9:48
• @H.Puc thanks, I didn't think about sth like that. Won't it add some noise at the output of my current source? Commented Jan 24, 2018 at 9:54
• There are many ways to do this. However, ready-made devices are available for this purpose. Why not just use one of those like a current meter. What is your advantage of making a current meter yourself if not for education purposes that is. Commented Jan 24, 2018 at 9:55
• @JavierGarcia if you are going to ask questions about noise you need to give more technical details of the current source and its noise levels. Commented Jan 24, 2018 at 9:56

## 2 Answers

Arduino has inbuilt 10-bit ADC which can measure voltage from 0-5 V. If the current to be measured is passing through a known resistor R, hook the nodes of the resistor to two analog pins on the arduino. Use analogread() function to find the two node voltages. Calculate the difference to get the voltage drop across the resistor. Then I = V/R. Calculate it and print the value on the LCD.

The answer is yes, it's possible. You have to do it in two steps. First read the current as voltage using analogue pins and second draw it on a display.

There are few ways to read the current. Build it yourself or buy a shield. Shield

The second sollution is use a differential OPA and a shunt resistor. This step requieres some calculations. I'm, adding you a good guide. Guide

As for the second step there are a lot of modules you can buy or you can do it yourself with any display and digital lines from arduino.

Hope this helps you. Good luck.