ELECTRONOOBS is on fire. Here we have the PCB he just ordered for his new project. After reviewing the TS100 portable soldering iron, he was amazed of the internal structure simplicity. So, he started designing his own board for a new project, a portable soldering iron. The board looks complicated but it’s quite simple. In the middle, the microcontroller and 4 pins for an OLED screen. That screen has i2c communication so SDA and SCL pins are needed. On the left side, a place for two push buttons can be seen. Those buttons will be used to set the desired temperature. On the left end we can see 4 pins, 2 for the heating element output, H+ and H- and 2 more for the thermocouple read, T+ and T-. The U1 chip is the MAX6675. On the back we have the huge MOSFET for power control.