In case anyone out there reading this doesn’t know, an oscilloscope is a piece of equipment that measures electrical signals and produces a graph of how they change over time. This is most notably useful when working with electronic signals that change in a short amount of time. I’ve rarely had a use for one in the past and considering how they typically range in price from hundreds to thousands of dollars depending on the feature set, I was never able to justify purchasing one for personal use. Although I secretly always wanted to have one just so my electronics workshop would feel more professional.
Since the last DIY electronics kit I tried was pretty fun to make and I ended up using it way more than I was expecting I would (which is to say I used it more than once). I decided that I’d give another one a try because building my own oscilloscope for less than $30 sounded like a good deal. Now my impression of the kit overall is much better than the power supply kit I made last summer. This kit came in a cardboard box with English text and logos on it, the case is made of injection molded plastic and isn’t 3D printed or laser cut and the PCBs are all double-sided and professionally manufactured, as opposed to laser etched or protoboard. Putting the kit together was also a little bit trickier thanks to the 3 separate PCBs but overall wasn’t too bad and only took about 2 hours with most of that time being spent measuring, testing and soldering the various resistors. I’m fairly impressed with the quality of the kit, with its only major downside being the lack of included power supply. The scope requires a 9V 5.5mm/2.1mm DC barrel jack power supply in order to run. Fortunately, I had a universal power supply on hand which did the trick.
As for the performance of the scope, I’m somewhat impressed. The voltage scale goes from 5mV to 20V, the timebase goes from 10 microseconds to 200 seconds and it will even give you measurements for stuff like cycle length/frequency and min/max voltages with a less than 5% error. It only has 1 channel which was to be expected so it means you can’t overlay two signals and compare them. But the only real deal-breaking flaw with the device is the limited bandwidth, which according to the spec sheet is only 200KHz. By comparison, a good quality oscilloscope has about 1000 times as much bandwidth in which it can measure signals all be it at 100 times the price. So no, this will not replace a real oscilloscope in 99.9% of use cases, but if you’re working within the range that it is capable of measuring then you’ll find that its a deceptively capable little device.
So doing this mod doesn’t make a whole lot of sense from the value perspective but I think it’s cool none the less. While this oscilloscope isn’t as useful as a benchtop model it does boast a significantly more portable design, which is hindered by its reliance on a wall outlet, so why not go the extra mile and make it battery powered? It’s not my first time working with LiPo batteries so I actually had a spare 2500mAh battery sitting around. Unfortunately, the original case doesn’t have space for it and the boost/recharge circuit so I went ahead and tracked down a new case on eBay. It’s only a 3D printed backplate which comes off as overpriced but its very well designed so I’m giving props to the creator. It’s not open source so you do need to pay for it and getting it shipped from Italy took 2 months which was a pain, but its way better than anything I could have made on my own. It came with printed wiring instructions too so it’s at very least professional.