# Hall Sensor ss495a DC current meter **URL:** \ **Category:** Projects\ **Created:** [January 12, 2016, 7:47pm UTC](https://community.sparkfun.com/t/hall-sensor-ss495a-dc-current-meter/32240 "2016-01-12T19:47:27Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![dannboyy](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@dannboyy](https://community.sparkfun.com/u/dannboyy)\ **Post date:** [January 12, 2016, 7:47pm UTC](https://community.sparkfun.com/t/hall-sensor-ss495a-dc-current-meter/32240/1 "2016-01-12T19:47:27Z")
I’m on a project to make a dc current meter for a few USB powered hardware. I was told that I could do that with the Hall Sensor SS495, but I just don’t know how to amplify (I don’t even know if I could do that!) the magnetic field generated by the USB cable or how to read properly in the arduino. Any ideas ? Thanks for the help! ---
**Author:** ![Valen](https://avatars.discourse-cdn.com/v4/letter/v/9dc877/32.png) [@Valen](https://community.sparkfun.com/u/Valen)\ **Post date:** [January 13, 2016, 6:49pm UTC](https://community.sparkfun.com/t/hall-sensor-ss495a-dc-current-meter/32240/2 "2016-01-13T18:49:28Z")
You will have to seperate the 5 volt wire from the ground wire. If you simply hold the hall sensor next to the unspliced USB cable the magnetic fields of both counteract each other. And just holding it near isn’t enough, it needs to be oriented in the right way. Then you may still need some amplification with an opamp circuit. You can use this one as a start. It amplifies the signal by 100 times. If that is too much there is a potentionmeter on it to reduce the result. But if you want to make something yourself then you will need to learn how to use opamps (operational amplifiers). [https://www.sparkfun.com/products/9816](https://www.sparkfun.com/products/9816) ---
**Author:** ![dannboyy](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@dannboyy](https://community.sparkfun.com/u/dannboyy)\ **Post date:** [January 14, 2016, 12:55pm UTC](https://community.sparkfun.com/t/hall-sensor-ss495a-dc-current-meter/32240/3 "2016-01-14T12:55:54Z")
Thank you very much. I’ll try here and say what happened. ---
**Author:** ![Valen](https://avatars.discourse-cdn.com/v4/letter/v/9dc877/32.png) [@Valen](https://community.sparkfun.com/u/Valen)\ **Post date:** [January 14, 2016, 2:26pm UTC](https://community.sparkfun.com/t/hall-sensor-ss495a-dc-current-meter/32240/4 "2016-01-14T14:26:14Z")
To be honest I don’t know if that amplification factor by that board is enough. It depends on how much current is flowing through the wire and the distance of the hall-sensor to it. Your mileage may vary. ---
**Author:** ![stevech](https://avatars.discourse-cdn.com/v4/letter/s/ba8739/32.png) [@stevech](https://community.sparkfun.com/u/stevech)\ **Post date:** [January 14, 2016, 7:39pm UTC](https://community.sparkfun.com/t/hall-sensor-ss495a-dc-current-meter/32240/5 "2016-01-14T19:39:42Z")
> dannboyy: > I’m on a project to make a dc current meter for a few USB powered hardware. I was told that I could do that with the Hall Sensor SS495, but I just don’t know how to amplify (I don’t even know if I could do that!) the magnetic field generated by the USB cable or how to read properly in the arduino. Any ideas ? Thanks for the help! Adafruit has a USB power "gauge" that displays in LEDs and numerically via a UART output. $10 ---
**Author:** ![dannboyy](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@dannboyy](https://community.sparkfun.com/u/dannboyy)\ **Post date:** [February 19, 2016, 11:57pm UTC](https://community.sparkfun.com/t/hall-sensor-ss495a-dc-current-meter/32240/6 "2016-02-19T23:57:50Z")
> stevech: > > > dannboyy: > > I’m on a project to make a dc current meter for a few USB powered hardware. I was told that I could do that with the Hall Sensor SS495, but I just don’t know how to amplify (I don’t even know if I could do that!) the magnetic field generated by the USB cable or how to read properly in the arduino. Any ideas ? Thanks for the help! > > Adafruit has a USB power "gauge" that displays in LEDs and numerically via a UART output. > > $10 THANK YOU VERY MUCH! THATS EXACTLY WHAT I NEEDED!