2.  Pi UART can select TTL/232 output

     Pi UART  TTL output TX,RX,GND,3V3,XX,XX

     Pi UART RS232 output GND, TX, RX

3. i2c signal out  GND,5V,SDA,SCL for extend extra  UART HAT

1.  provide extra 2uart  TTL output

     TTL output signal  TX,RX,GND,3V3,CTS,RTS

2.  Pi UART can select TTL/232 output

     Pi UART  TTL output TX,RX,GND,3V3,XX,XX

     Pi UART RS232 output GND, TX, RX

3. i2c signal out  GND,5V,SDA,SCL for extend extra  UART HAT

No3.  2uart-Pi-Ze 

1.  provide extra 2uart  TTL output

     TTL output signal  TX,RX,GND,3V3,CTS,RTS

2.  Pi UART can select TTL/232 output

     Pi UART  TTL output TX,RX,GND,3V3,XX,XX

     Pi UART RS232 output GND, TX, RX

3. i2c signal out  GND,5V,SDA,SCL for extend extra  UART HAT

4. 2 Port RS232 /RS485 extension module connect

No3a. 2uart-232-m01    

1.  provide 2 Port DB9 RS232 output

No3b. 2uart-232-485-m01

1.  provide 2 Port DB9 RS232 output

2.  provide 2 Port RS485 2 wire  output

3. RS485 RTS signal High/Low select jumper

1. 2 UART TTL + one UART(Pi)
2. 1 UART TTL + one UART(Pi) with extra 4 GPIO output
3. 1 UART TTL + one UART(Pi)
4. 2 UART TTL + one UART(Pi) with Extension socket
5. 2x RS232 extension Module
6. 2x RS232 /2x RS485 extension Module

1. 2uart-Pi-Ze plug in Pi Zero

2.  2uart-Pi-Ze+2uart-232-485-m01 Module  plug in Pi Zero