PL2303 USB to UART (TTL) breakout
It's a small USB to TTL serial tool, using the PL2303 chip.
You can use it to connect some serial device to your PC via USB port, an avr, an msp430 or an stm32 for example.
It's very cheap compared to the ft232 alternative and works very well, up to more than 1mbit/s.
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