The Raspberry Pi is equipped with a GPIO port (general purpose input/output) which allows programs to communicate directly to connect devices and circuitry. If you are interested in tinkering with electronics or expanding the capabilities of the Raspberry Pi then the GPIO is the gateway to your projects.
If you are unfamiliar with using GPIO port then research what you want to do before connecting anything as you can easily damage the Raspberry Pi through miswiring and using the wrong voltages.
The Raspberry Pi is a great alternative to using a PC or Laptop for electronics projects due to it's size and low power requirements and paired with micro controller cards and other devices can be used as the brain for robots, home automation systems, security systems and thousands of other projects.
The GPIO port can also be used to add additional circuitry to the Raspberry Pi and expand it's general functionality. Below is a collection of devices that are used with the GPIO port.
Arduino make various microcontroller boards that can be programmed to control many real world devices without the need of a computer such as the Raspberry Pi but if you are working on more advanced electronics projects then pairing the Raspberry Pi with an Arduino card could be a good option.
Arduino also make prototype shields that can be used with the Raspberry Pi in circuit design and testing for Raspberry Pi electronics projects.
More information at Arduino.cc
The Berry board is a simple self assembly kit that adds 6 LEDs, a buzzer and a button to the Raspberry Pi via the GPIO port. These can the be programmed to give you visual or audio feed back to events happening on the Pi or within your programs. A useful and fun project for anybody wanting to start programming and use the Pi's GPIO port.
Test scripts are available written in Python to get you started.
More information at www.raspberrypi-spy.co.uk
PiCrust connected to a Raspberry Pi
The PiCrust is an add on board that breaks out the GPIO connections into female connectors grouped into 2 x SPI, 2 x I2C, 1 x UART, 8 x GPIO. The PiCrust is small enough to fit snugly into the profile of the Raspberry Pi so could fit within some cases.
More information at picru.st
AB Electronics UK
From left to right; Clock with battery, Analogue to Digital Audio Converter, Port Expander, Logic Converter
AB Electronics have a selection of add on boards that are stackable using the GPIO port.
Boards available include;
- A battery powered real time clock. The Raspberry Pi gets the time from the internet so if your Pi is not used online and your use requires time, such as timed automation then this boards is your solution.
- For Audio there are three 8 channel and analogue to digital converters. Four boards are stackable allowing up to 32 ADC inputs.
- A port expander allowing the Raspberry Pi to have 32 digital input and outputs. Four boards can be stacked giving a total of 128 I/O ports.
- A logic level converter allowing device that use 3.3 volts and 5 volts to safely interface.
More information at www.abelectronics.co.uk
The Pi-Face digital interface is a device that connects the Raspberry Pi's GPIO port that allows the Raspberry Pi to control sensors, motors, actuators, lights and anything else that responds to digital inputs.
A detailed article is now available here
The PiBorg is a robotics controller card that is used with a Raspberry Pi to control motors and solenoids. The PiBorg can be daisy changed to allow a Pi to control up to 10 motors and 10 solenoids or 30 solenoids with no motors.
The PiBorg comes pre-assembled or a kit is available if your would prefer to solder your own.
More information at piborg.org
LedBorg illuminating a Raspberry Pi in a clear case with a selection of colours
Led Borg is a small add on board that has a programmable multicoloured LED light that can display 26 colours. This can be used as a status display to show different colours as the Raspberry Pi performs different tasks or just as a light to illuminate your Pi in different colours each day.
More information at piborg.org
The RasPiComm boards add the serial communication ports RS-232 and RS-485 to the Raspberry Pi.
RS 232 ports are used to communicate to other computer devices with serial device. RS 485 ports are used for controlling external devices such as motors.
The RasPiComm board is a small board that fits within the profile of the Raspberry Pi and also includes a battery powered clock, a direct IC2 connector for adding sensors and displays and a mini 5 way joystick.
Drivers for a OLED display, a stepper motor controller and remote control via Ethernet or WiFi are available on the website.
More information at https://amescon.com/
Quick 2 Wire is a another project in the final stages of production with their first open source boards, an interface board breaking out the GPIO port into easy connectors with safety features, a port expander and finally an analogue board . The boards will be available as make yourself kits. They have various other boards lined up for the future so worth keeping an eye on.
More information at https://github.com/quick2wire
Adafruit Pi Hardware Add-ons
Adafruit has a few add on devices for the raspberry Pi which include breakout boards using solderless connectors to give you easy access to the GPIO port power, GPIO, I2C and SPI pins.
They also have a prototyping plate that sits directly on the Raspberry Pi and also a 16 x 2 LCD display with 5 control buttons which allows text feedback and status updates directly from the Pi. Great if you are not using your Rpi with a TV or Monitor.
More information at www.adafruit.com
Pridopia Limited GPIO I/O Boards
Pridopia specialise in I/O add on boards and have a range of various GPIO add on boards for the Raspberry Pi.
From top left to right
1. Rs-Pi-4 USB Hub + Multi-function i2c Board
2. Rs-Pi-4 USB Hub +32 GPIO(i2c/SPI) Board
3. Rs-Pi-7 USB Hub+ Multi-function i2c Board
4. Rs-Pi-7 USB Hub +16 GPIO (i2c/SPI) Board
5. Rs-Pi-32 channel PWM/Servo Board
6. Rs-Pi-16 channel PWM/Servo & 16 GPIO (i2c/SPI)Board
7. Rs-Pi-32 GPIO (i2c/SPI) Board
8. Rs-Pi-64 GPIO (i2c/SPI) Board
9. Rs-Pi-128 GPIO (i2c/SPI) Board
10. Rs-Pi-Multi-function 32 GPIO (i2c/SPI) Board
11. Rs-Pi- uln2803 SPI AD/DA -1-Wire Multi-function Board
12. Rs-Pi- 2 Relay + Step Motor Board
13. Rs-Pi- LED 16x16 Matrix Board
14. Rs-Pi- USB-TTL Console Board
15. Rs-Pi- RS232 Console cable
16. Rs-Pi- uln2803 & 1-Wire Board
17. 4 Relay Extension Board
More information at www.pridopia.co.uk/ixx-rspi.html
Robogaia 4 Relay Raspberry Pi Plate/Sheild
The 4 Relay Raspberry Pi Plate/Sheild is a GPIO add on board that allows you to switch on and off four devices that use much higher voltages than the Raspberry Pi can handle directly. The Raspberry Pi uses 3.3 volts but if you want to switch a device on and off such as a motor, a 12 Volt lamp or home automation then you will need to use relays.
This board allows you to control 4 relays independantly up to a recommended voltage of 24 Volts. Sample code is available on the Robogaia website to control the relays.
For more information vist the Robogaia website at www.robogaia.com/4-relays-raspberry-pi-plateshield.html