Recently I purchased an inexpensive usb based oscilloscope to help me do some low level electronics debugging. Owning an oscilloscope is so cool I just had to tell everyone about it! And the price of these USB-based oscilloscopes are in range of many hobbiests. Now I'm kicking myself for not buying one of these years ago.
The above screen shot shows the output of an ATTINY13A microcontroller (similar to what the ardupilot uses for their fail safe / manual override circuit.) My test code reads a PWM signal in (via an interrupt service routine) and generates a new signal out on a different pin that mirrors the input signal. I can see exactly what is going on with both the input and the output pins using my cool new oscope.
I'm learning as I go (just like everyone else) but I thought it would be fun to share my experience in a bit more detail and hopefully encourage some people here to also take the plunge. I have many more details and screen shots posted at my personal blog here:
http://gallinazo.flightgear.org/technology/how-to-be-an-electronics-whiz-on-a-small-budget/
Comments
I usually use the line in/microphone input to analyse signals, it's not the same than above solutions but it's enough for me.
Days of scope have come I guess, i bought the kit from sparkfun , it was fun to assemble it, wish it was PC compatible too but you can't ask too much for 40$( it was 40 think when it was when I bought it) .. the dealextreme site is down right now how ever
There has been a price revolution on digital sample oscilloscopes the last 2-3 years. And we are not talking about cheap "playing-at-home" scopes either, but professional quality proper electrical engineering scopes.
If you are in the marked for a "proper" table scope at ridiculous prices, I have nothing but good things to say about Rigol scopes. A great entry level 2 channel scope is the DS1052E (http://www.dealextreme.com/p/rigol-ds1052e-5-6-tft-lcd-50mhz-2-chan...).
In fact we have started using them at work since they do at least 95% of the things we need just as well as a $8000 scope, but at 1/20 the price. That way everyone including the janitor get a scope if they want one.
Agreed. And for the sort of thing shown above, a USB logic analyzer is even cheaper, simpler and smaller. I love the Saleae Logic, which is tiny and incredibly easy to use.