“Some time ago I got one of these transistor testers on eBay for around 10$. It is quite useful, specially because my multimeter does not measure capacitance or inductance. I did a samll write up about it in portuguese here. First thing I noticed was the popular Atmega 328p on the back of the board. For some reason, I tried to calibrate it (there was no need) and messed up the values. Whatever was wrong, was inside the chip, specifically inside the chip’s eeprom. I found a way to read and program the chip, and then tried erasing the eeprom using avrdude, but could not get the measurements right. This made me think the board already comes calibrated from the seller. Because it was so easy to program the chip, I had decided that if I could not get it working I would just use it for anything else. I turns out I was just using a small capacitor when calibrating it, after using a capacitor of higher value than the recommended it worked just fine. Anyways, the atmega328p used on the board it is the same present in many duinos out there(UNO, Nano, Mini, a thousand clones.. etc), so it got me thinking “Why something so hackable is not being hacked?”. I mean, it has an LCD screen, a sort of button, battery connection, and a SPI port available.”
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