Update: Since, as a reader so astutely pointed out, we already blogged this item (the ONE time I forget to search for prior postings), may I interest you in a Parallax USB Oscilloscope? It was featured on the Introduction to Oscilloscopes Make: Podcast back in February. It’s a 2-channel digital scope that looks pretty impressive for the $140 pricetag. It’s seen here in its Understanding Signals educational kit form, which includes a guide book and additional parts for an extra $20. Such a deal!
Parallax USB Oscilloscope – Link
We now return you to our regular blogcast, already in progress…
If you’re looking to learn more about oscilloscopes, but don’t have a lot of money, you can get started on the cheap by using a PC scope with an oscilloscope hardware module. Over at fpga4fun, they’ve put together a “recipe” for making a hardware interface using a Pluto FPGA board and a Flashy acquisition board. The parts will cost you between $80 and $100, depending on what you already have on hand. And you only end up with a single-channel oscilloscope. But you can get a two-channel o-scope by replacing the Pluto board ($40) with a Saxo board ($90). and the single-input Flashy ($30) with a FlashyD ($70). As you can see, the cost starts to mount (bringing eBay bargains on analog scopes within the ballpark), so I’m not sure how sensible this is if you’re looking for an everyday piece of test equipment. But as a fun electronics project… ?
8 thoughts on “Cooking up a cheap digital o-scope”
Comments are closed.
If you are just looking for a cheap digital 0-scope the Parallax USB O-scope is fine at $159. On the other hand this project would seem to provide a lot of insight into real time data acquisition.
You’ve covered this before:
http://www.makezine.com/blog/archive/2007/04/how_to_make_a_digital_osc.html
Oops. The ONE time I forget to do a search for prior posting…
Many of the “bargains” on analog scopes on Ebay are not as great as they first appear – the really cheap scopes up for sale probably haven’t been calibrated in years. Calibrating an analog scope requires one either already have the knowledge and a bunch of expensive test equipment, or getting it done professionally which can cost at least one or two hundred bucks, if not much more if it’s a higher bandwidth ‘scope.
With that in mind some of the PC based oscilloscopes start to look like a good value, but $140 for the first scope is a lot when it’s limited to a 200khz bandwidth; that’s not really sufficient to even do audio frequency work. 10Mhz 2 channel hardware scopes can be had for around $250 new….