Peter Balch has an oscilloscope; in fact, he has four (or perhaps five now), but he notes that sometimes it would be really useful to have something portable that could be used as easily as a multimeter. As described in his recent write-up, portability is no longer a problem for him, as he’s come up with a small oscilloscope that he calls the “ArdOsc,” so small that it can nearly fit inside of a matchbox.
To go along with its compact form factor, the device can be made for the similarly small price of an Arduino Nano, a display, a few discreet components, and perhaps a battery if you so choose. It is, however, capable of taking one million samples per second. While this wouldn’t compete with lab-quality benchtop equipment it’s certainly respectable for a handheld scope.
The tutorial goes through how to make the ArdOsc, starting out with a version so simple that it only needs four resistors, three capacitors, and the Nano. Display here is via the user’s computer screen. From there, more complicated versions add a logic display, trigger, signal generator, frequency counter, and even a voltmeter. And of course, a screen. So if you’ve ever wanted to build your own really, really tiny oscilloscope, Balch’s project is certainly worth a look!