Description CH559 has more features and bigger flash size. Support USB hub, two USB transceiver, one is normal speed (female A USB pin “DP DM” and micro USB), one is high speed (On board marked “HS USB, pin HP HM”). All lead out pins. On board power led, four programming leds IO P1.4-P1.7. Fuse protection on input power pins 3.3V and 5V. 2*3 jumper select 3.3V / 5V and ON/OFF, both 5V or 3.3V can work by chip. Lead out pinheader 1×4: serial UART port, logic level complaint. On board optional crystal reserved. USB directly programming. To enter into flash bootloader mode, hold down PROG button, and press RESET button. New version improve the USB part, and board layout All documentation please find at CH55X wiki page or this page V2 , or customer github. WCH CH55x Series: CH551 CH552 and CH554 CH559 USB CDC Touch Relay Control Board CH554
