4x UART Box - RS232 x2 /RS485 x2  - with Raspberry Pi  3B


1. Provide RS232 x2 & RS485 x2  RJ45 output
2. Can Choose RS232 x4  link
3. RS485 auto RTS control by software
4. On board DS18B20 1Wire Temperature sensor (Option)
5. Provide 8 GPIO control LED
6. 1 GPIO 5V Mini Fan control pin (ON/OFF control ) ( 2.0mm / 2.54mm pitch )
7. On board RTC function with CR1220 Battery socket
8. 4 UART  Board Power select jumper from Pi or Micro USB
9. 5V Mini Fan Power select jumper from Pi or Micro USB
10. It provides an individual 3.3V power for UART Board
11. Provide HAT EEPROM for future driver program update.
12. One software control Micro Switch for Program ( Shut Down , reboot....)
13. use 20x2 40pin cable connect to Pi
14. PCB size 110mm x 85mm
15. Box size 200mm x 125mm x 55mm
16. 80mm x80mm & 40mm x40mm fan screw hole
17. PASS CE FCC certificate
18. Raspberry Pi model 3B still can use on board Bluetooth & WiFi



RJ45 to DB9  (RS232/RS485 ) test cable



 80mm x 80mm - DC fan


40mm x 40mm - DC fan


Driver Load , system info and demo  Send/Receive Python program 

1. receive python program use COM1, COM3
2. send python program use COM 2, COM 4
3. i2cdetect screen you will see 4c, 4d and UU in 68 location
4. Scan.sh display COM1 ~ COM 4 correct address /dev/pts/x
5. "top" system info ( you will see 2 x Pi485 & 2 x Pi232 )
6. "df"  display Pi system resource , also "uname -a " display Pi OS Ver
7. auto run python program fanon-sw.py you will see LED 1~7 flashing, LED 8 ON --- Fan ON,
  press Micro Switch hold for 2 ~ 3 sec, Fan & LED will OFF




   RS232 with RJ45 Pin 1  to Pin8  output 


  RS485  with RJ45 Pin 1  to Pin8  output  

  XXX  XXX   D+  GND   XXX  XXX   D-   XXX

     1     2       3       4        5      6      7      8



 2x RS232 - 2x RS485  Board use power from Micro USB

 (8 GPIO control LED ON )



2x RS232 - 2x RS485 Board use power from Pi (8 GPIO control LED ON )


Serial GUI Control Panel
Control up to 4 Serial Ports


  • 1. Scan: Scan for available UART devices.
  • 2. Launch cutecom together when starting Serial Port.
  • 3. Port number in system
  • 4. Baud Rate choose
  • 5.6.7.  UART Port  Information:  Port Address 0x48,0x49, 0x4c, 0x4d

              Chip Address Location, Channel Number ( 1 / 2 ), TX and RX receive counter,

              and Serial port Location /dev/pts/X

  • 8. RS485 : Enable RS485 in this Port
  • 9. Start : Start UART port


Also provided is a terminal command mode to activate serial ports through a terminal / ssh.
You can also activate a serial port on boot up with the provided software.
Commands for starting the serial ports via command line;
./Pi232 -a ADDR -c CHANNEL -b BAUD -s DEVPTS

./Pi485 -a ADDR -c CHANNEL -b BAUD -s DEVPTS

ADDR = Address of Serial Port e.g. 0x48, 0x49, 0x4C, and 0x4D
CHANNEL = Channel of serial Port ( 1 / 2 )
BAUD = Baud Rate for the Serial Port
DEVPTS = PICOM Service Number ( Will direct the filename to /dev/picomX where X = your number )

For example, To start a serial port from 0x49, on channel 2 with 115200 Baud run the following;
./Pi232 -a 0x4d -c 2 -b 115200 -s 1
This will activate the serial port and then set /dev/picom1 to your serial port location /dev/pts/X

./Pi485 -a 0x4c -c 2 -b 115200 -s 1
This will activate the serial port and then set /dev/picom1 to your serial port location /dev/pts/X



     Enable RS232 in command mode   



  Enable RS485 in command mode




1. device ->   /dev/pts/1        2 . Baud rate  38400

3. click Open device  

4. input AT command (HC-05 blutetooth module)

5. screen will show Bluetooth module response  


type "top" in terminal 
Enable 4 Port RS232 x2 - RS485 x2 
 You will see 2 x Pi232 & 2 x Pi485 run in system 
 File Download      

  Software Pack

  User Manual


Package Content

  1x Rs-Pi 3B RS232x2 - RS485x2  4xUART Box

1x Pi 3B  with 16 GB Micro SD card ( include driver & demo program)

  1x 40 mm x 40 mm  DC fan

2x RJ45 to DB9 - 10cm  (RS232/RS485) function test cable

  1x manual 



Raspberry Pi

extra UART




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