SP3232, DB9 interface female, UART interface. RxOUT: connect to MCU.RX (Signal flow direction: MCU.RX << SP3232 << PC.TX). TxIN: to MCU.TX (signal flow: MCU.TX >> SP3232 >> PC.RX). CTS: Connect to MCU.CTS (Signal flow: MCU.CTS << SP3232 << PC.RTS).
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