The processor is STM32F103T8U6, 72MHz M3 core with 64K Flash and 20K SRAM, 2 12-b ADC. It includes a 3-axis digital accelerometer for motion and orientation detection, 96x16 OLED display, a temperature sensor, TMP36 and two push buttons. It has a barrel connector (5.5mm x 2.5mm) for power and a micro USB connector for firmware update. The tip contains a thermocouple (reported to be type K); TMP36 provides the cold junction compensation. The circuit design seems decent; it does not aim for the lowest cost possible. For the price of about $50, it should not need to skimp on the circuitry. I would estimate the bill of material costs do not exceed $20. With 12V input, it takes about 30s to heat up to 300C; with 19V input (40W) from a laptop power adapter, it takes about 12s.
With the right firmware, it does make a nice soldering station. The tip temperature is settable up to 450C. The iron goes to sleep on a timer and wakes up on motion. It can be made portable with a LiPo pack; the cutoff voltage is settable based on number of cells. Because of the small size, a stand can be made out of a paper clip.
