- Wed May 09, 2012 3:44 pm #144223
Thanks for the example. I figured you would use a logic analyzer to decode serial messages but now I can see (edge timing) why an o-scope is important too. What do you think of the cheap Rigols?
dkulinski wrote: What do you think of the cheap Rigols?Not bad actually ! All you can expect to get at about $300 is 2 channels, 40-60 Mhz bandwidth and 8 bit sampling. Look at the specs for the DS1052E which was being compared to the MSO-28.
dkulinski wrote:I know you spoke about getting an O-scope, I just picked up an old Tektronix 465M in perfect working order. Found it on craigslist, I setup a "recipe" on ifttt.com to email me whenever an oscilloscope showed up for $200 or less. I paid $150 and tested it tonight.Funny, I did the exact same thing. I love ifttt.com. I'm getting hits, but I haven't found one yet that is both in my price range and with the features I think I need.
So you can find an old analog oscilloscope pretty cheaply that has a lot of bandwidth for these simple projects. I hooked it up to the crystal on the lasertag prototype and I was able to see a 16MHz wave, very very neat stuff!
Of course I can't play back samples but I setup a simple sketch to run a PWM on the arduino and I watched the falling and trailing edges and was able to see just how noisy those edges were.
Now I think rather than a DSO I will go for a logic analyzer next. There are a couple of them on Sparkfun and I think that will be what I pursue. Hopefully that will give you some insight on an o-scope purchase.