- RS232 Master Port.
- Control the Raspberry Pi over RS232 or connect to external serial accessories.
- Stackable with other Raspberry Pi accessory boards.
- Mounting holes for use with the AB Electronics UK mounting kits (sold separately)
The Serial Pi Plus is a communication board supporting the RS232 serial protocol, designed for use on the Raspberry Pi and other compatible single-board computers.
The RS232 port is connected to the UART port on the Raspberry Pi using a MAX3232 or ICL3232ECBNZ* interface. The MAX3232 and ICL3232ECBNZ* ICs convert the 3.3V UART port to RS232 voltages, allowing communication with RS232-compatible devices over a DB9 serial cable. With a null-modem cable, the board allows terminal access with Linux on the Raspberry Pi using a terminal application. The RS232 port can be accessed through the DB9 port or the solder points on the PCB.
An array of 2.54mm pitch holes with 3.3V and 5V connections are also provided on the PCB, allowing you to build additional circuits on the board.
Please note that you can only use one Serial Pi Plus board on a Raspberry Pi. If stacking with other boards, we recommend putting the Serial Pi Plus at the top of the stack due to the height of the DB9 connector.
Connecting to the RS232 Port: You need to use the latest Raspbian Jessie release and disable the built-in Bluetooth to use the Serial Pi Plus on the Raspberry Pi 3 or Raspberry Pi Zero W; see our KB page for the config changes needed.
The RS232 port on the Serial Pi Plus can be accessed through the male DB9 socket or the solder points on the PCB. The DB9 socket is configured as a master socket, as you will find on desktop computers, allowing you to connect external serial devices with a standard RS232 cable.
*Due to global component shortages, Serial Pi Plus boards manufactured after 23/11/2022 may use the Intersil ICL3232ECBNZ RS232 interface IC. The ICL3232ECBNZ is a pin-compatible replacement for the Texas Instruments MAX3232.
Legacy Serial Pi Versions
See our KB article for previous versions of this board.
Compatibility
We have tested the Serial Pi Plus on the following platforms.
| Model |
Status |
| Raspberry Pi Model A / B |
|
| Raspberry Pi 1 Model A+ / B+ |
|
| Raspberry Pi 2 Model B |
|
| Raspberry Pi 3 Model A+ / B / B+ |
|
| Raspberry Pi 4 Model B |
|
| Raspberry Pi 5 |
|
| Raspberry Pi Zero |
|
| Raspberry Pi Zero W / Zero 2 W |
|
| Raspberry Pi Compute Module 4 IO Board |
|
| Raspberry Pi 400 |
|
| Orange Pi |
|
| Odroid |
|
*You need to use the latest Raspberry Pi OS release and disable the built-in Bluetooth to use the Serial Pi Plus on the Raspberry Pi 3, 3+ and 4. See our KB page for the config changes needed.
