DIY Voltmeter: Build Your Own Card for MATLAB Plotting

[El Moriana]

Hi,

I recently got it into my head that I would like to make an analog-digital interface card for my laptop such that I can plug two wires into the card and have the the card send data on the potential difference between the two wires to my laptop via the USB port. The plan is to then have MATLAB display a running plot of this data.

This is my goal, however I am new to electronics and have absolutely no idea how to go about doing this, in terms of components (what the card would actually need to accomplish its purpose) and in terms of how to successfully interface it with MATLAB. If possible, I'd really appreciate some guidance as to how to go ahead with this. At least so I know what direction to start going in.

 

[jsgruszynski]

Hi,

I recently got it into my head that I would like to make an analog-digital interface card for my laptop such that I can plug two wires into the card and have the the card send data on the potential difference between the two wires to my laptop via the USB port. The plan is to then have MATLAB display a running plot of this data.

This is my goal, however I am new to electronics and have absolutely no idea how to go about doing this, in terms of components (what the card would actually need to accomplish its purpose) and in terms of how to successfully interface it with MATLAB. If possible, I'd really appreciate some guidance as to how to go ahead with this. At least so I know what direction to start going in.

A-to-D converters (ADC) measure voltage so that's a starting point. Most DIY folks seem to use sound cards (audio input) as their "easy to implement with the stuff on-hand" ADC. There are also commercial and hobby USB ADCs and voltmeters available but there is a trade between cheap vs. easy/accurate. Google "USB voltmeter".

Specifics of MATLAB interfacing? The simple answer: you'll most likely get to do all that yourself.