DIY servo tester based on ATTiny85

Here is a really small side project that I developed while working on something else…
I had to test a RC speed controller that I wanted to use to control an electric car window motor, and for the 100th time I was facing the same dilemma: find 8 batteries for my remote control, dismount the RX part from the quadcopter and use that, OR grab the Arduino and write quickly some code to generate the corresponding signals ? Neither of which was actually particularly handy…

So I finally decided to build a small stand alone servo tester :
The hard part was to avoid trying to squeeze too many features in it, as I kept thinking that having an LCD screen showing the exact pulse width in microsecs would be useful, etc. ….
I finally managed to convince myself that “less is more” and the final design simply has a micro-controller (what else than the trustworthy AtTiny85 !?  🙂 )  and a big knob (that I salvaged from a radio).
Here’s some sort of schema, though that’s probably an overstatement
A, yes, sorry there is also a small capacitor to avoid noise from the motor affecting the MCU (see the lesson I’ve learned here, the HARD way !) and a LED, to give some basic visual feedback, at least when the device is operating.
And here is the simple and clean soldering at the back (I’m becoming quite good at this, it’s almost like a craft: initially how to position the parts to minimize the distances and then how to re-use existing connections to minimize extra soldering… ), I probably should one day make the leap to design proper PCBs…
 
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