MikroElektronika Figure 1: USB UART additional board FP1 FERRITE CN1 USBDM USBDP RX-MCU DTR DCD DSR RI RTS-MCU TX-MCU CTS-MCU P3 P1 P0 P2 P4 OSCI DTR# OSCO TXD TEST VCC RTS# DSR# AGND RESET# VCCIO DCD# NC GND RXD CTS# CBUS1 USBDM GND CBUS2 GND USBDP NC CBUS3 CBUS0 3V3OUT RI# CBUS4 FT232RL U1 3V3OUT C4 100nF C1 C2 100nF 100nF VCCIO E1 10uF VCCIO RX-MCU DTR RI TX-MCU P4 DCD CTS-MCU P3 DSR P1 RTS-MCU P2 P0 CN2 CN3 J6 VCC 3V3OUT VCC VCCIO 22.16mm 26.92mm Figure 3: USB UART additional board connection schematic Figure 4: Dimensions of the board How to connect the board? The USB UART additional board is connected to USB devices via the USB MINIB connector CN1. Connection with the microcontroller is established via a 1x6 connector CN2 and 1x9 connector CN3. Jumper J6 is used to select a logic level to be sent to the VCCIO pin on 1x6 connector CN2. This logic level may be 3.3V or 5V. USB UART The USB UART additional board is used to connect USB devices to the UART module built into the microcontroller. Key features: - Serial data transfer via UART communication; - 5V DC power supply voltage; - Low power consumption; etc.