This is a universal JTAG/SWD/UART/SPI/... adapter based around the FT2232H chip. This initially started based off the KT-Link specifications, but has since evolved into the following set of features: ...
Additional circuitry required. One Diode (I use 1n4004) - pole/cathode at tx pin other at rx pin. 4k7 Ohm resistor between rx and 5V (3.3V also works). Same at the other microcontroller but you don't ...
Other features include an SHTC3 temperature and humidity sensor, a PCF85063 RTC, a microSD card slot for storage, along with multiple GPIO, UART, and I²C expansion headers. Power, programming, and ...