Seeing the popularity of the TS-100 soldering iron, GitHub user [ole00] found himself desirous of a few of its features, but was put off by its lack of a power supply. What is a hacker to do? Find a cheaper option, and hack it into awesomeness.
[ole00] stumbled across the inexpensive ZD-20U and — despite a handful (sorry!) of issues — saw potential: it’s compact, lightweight, and powered via a USB power cable. Wanting to use as much of the ZD-20U’s original board as possible, the modifications were restricted to a few trace cuts and component swaps. The major change was swapping out the 555 timer IC controlling the iron with am ATtiny13a MCU to give it a bit more control.