Model A+ - Power outlet Raspberry Pi - Free user manual and instructions

Product Type	Single-board computer
Model	Raspberry Pi Model A+
Manufacturer	Raspberry Pi Foundation
SoC	Broadcom BCM2835
CPU	700 MHz single-core ARM1176JZF-S
RAM	256 MB SDRAM
Storage	microSD card slot
USB Ports	1 x USB 2.0
Video Output	HDMI, composite video
Audio Output	3.5 mm jack, HDMI
GPIO	40-pin header
Power Supply	5 V via microUSB, 200 mA typical (1 A recommended)
Dimensions	65 mm x 56 mm x 10 mm
Weight	23 g
Operating System	Raspbian (Linux-based)
Wireless Connectivity	None (requires USB dongle or GPIO module)
Main Function	Control wireless mains sockets via 433 MHz LightwaveRF protocol
Programming	Compatible with WiringPi, Python, C
Included Accessories	None (board only)
Cleaning	Keep dry, clean with soft cloth, avoid liquids
Safety	Use appropriate power supply, avoid short circuits, keep away from water
Repairability	GPIO pins replaceable; main board not user-serviceable

Frequently Asked Questions - Model A+ Raspberry Pi

How do I control wireless mains sockets with a Raspberry Pi?

Use a 433 MHz transmitter module connected to the GPIO pins. Employ the LightwaveRF library and send on/off commands via a simple program. The article describes using the lightwaverf-pi library with WiringPi.

What is the LightwaveRF protocol?

LightwaveRF (LWRF) is a home automation protocol operating at 433 MHz using On/Off Keying (OOK) modulation. It has been reverse-engineered, and libraries are available for Arduino and Raspberry Pi.

What hardware is needed for this project?

You need a Raspberry Pi (any model), a 433 MHz transmitter module (e.g., QAM-TX1-433), a breadboard, jumper wires, and a compatible LightwaveRF mains socket.

How do I connect the 433 MHz transmitter to the Raspberry Pi Model A+?

Connect the module's VCC to 5V, GND to ground, and DATA to GPIO pin 12 (physical pin 12, which is GPIO 18). Attach a 174 mm antenna wire to the ANT pin.

What software do I need to install on the Raspberry Pi?

Install the WiringPi library for GPIO access, then download and compile the lightwaverf-pi library. Follow the instructions at the provided repository.

Can I use the Raspberry Pi Model A+ for other home automation tasks?

Yes, the Model A+ is a general-purpose single-board computer. You can use it for a wide range of projects, including controlling lights, sensors, or other 433 MHz devices.

How do I power the Raspberry Pi Model A+?

Use a microUSB power supply providing 5 V. The board typically draws about 200 mA, but a 1 A supply is recommended for stability, especially with peripherals.

What is the difference between Raspberry Pi Model A+ and B+?

The Model A+ has 256 MB RAM, one USB port, and no Ethernet port. The B+ has 512 MB RAM, four USB ports, and an Ethernet port. Both have the same GPIO header.

How do I pair the LightwaveRF socket with the Raspberry Pi?

Put the socket into pairing mode (refer to its manual). Run the send program with the 'on' command. If successful, you can then control the socket on/off.

Are there any safety precautions I should take?

Ensure the power supply is adequate and avoid short circuits on the GPIO. Do not connect mains voltage directly to the Pi. Use only low-voltage components.

USER MANUAL Model A+ Raspberry Pi

Control wireless mains sockets with Arduino and Raspberry Pi

Posted by stuartChilds on Tue, Jan 13 2015 16:39:00

LightwaveRF (LWRF) is a range of switches, dimmers and other home automation hardware that is widely available in the UK and further afield, sometimes sold under other brands such as Siemens. They are affordable units that are easy to work with.

Working with off-the-shelf products, such as remotely switchable mains sockets, means that we can concentrate on control without having to deal with mains voltages directly.

A set of 3 switchable mains sockets can be bought for around £20 – including a remote that appears to be compatible with up to 16 switches in total. Here we will replace this remote with our own wireless hardware, so that we can have programmable control.

The LightwaveRF protocol

One great thing about the LWRF protocol is that it fairly simple and has already been reverse engineered by people looking to build their own home automation systems. This means that we can use readily available libraries and examples to quickly interface a microcontroller or computer with the hardware.

The LWRF system operates on 433 MHz and uses simple On/Off Keying (OOK) modulation, whereby the carrier is turned on and off to transmit information. Low cost transmitter modules suitable for use with Arduino and Raspberry Pi are commonly available.

Arduino control

Hardware required:

• Arduino (any AVR based model)
• Prototyping breadboard
  • 433 MHz transmitter module
• Jumper wires
• LWRF mains socket

First we will connect the radio module.

• The QAM-TX1-433 module has 4 pins:
- ANT (Antenna) – a 174mm length of solid core wire makes for a suitable antenna.
- VCC – 5v from Arduino.
• DATA – Arduino pin 3 for the unmodified 'lwsend' sketch.
• GND – ground connection to the Arduino board.

We'll be using the excellent LightwaveRF library written by Lawrie Griffiths. Add this to your Arduino libraries folder and upload the 'lwsend' example to your Arduino.

Now open the serial monitor and try sending '1' or '0' to the Arduino. If this looks to be working, try pairing the Arduino to the LWRF socket by putting the socket in 'pairing mode' (see the supplied instructions) and sending '1' over the serial monitor to the Arduino, so that the 'on' command is sent.

The 'lwsend' sketch is pre-configured to transmit compatible LWRF on/off control signals. If the pairing was successful you should now be able to turn the socket on and off with your Arduino.

Raspberry Pi control

Hardware required:

• Raspberry Pi (any model)
- Prototyping breadboard
• 433 MHz transmitter module
- Jumper wires
- LWRF mains socket

The same wireless module (QAM-TX1-433) is used in much the same way we did with the Arduino:

• ANT (Antenna) – a 174mm length of solid core wire makes for a suitable antenna.
  • VCC – 5v from Raspberry Pi.
• DATA – Pin 12 on connector P1 for the unmodified lightwaverf-pi 'send' program.
  • GND – ground connection to the Raspberry Pi.

Here we will use a version of Lawrie's LightwaveRF Arduino library that has been adapted for use with Raspberry Pi.

This port makes use of the WiringPi library, which simplifies the use of GPIO on the Raspberry Pi and provides a familiar environment for Arduino developers.

Install the WiringPi library by following the instructions here. Next add the LightwaveRF-pi files and compile by following the instructions here. Now you should have two executables that can be used to send the correct 'on' and 'off' signals to control the socket.

Summary

Now it is possible to use an Arduino or Raspberry Pi to control wireless mains sockets, this capability can be easily integrated into custom Arduino and Linux-based home automation projects.

With a little extra work it is also possible to control multiple sockets, dimmers and other LWRF home automation products. For details of the LWRF protocol see:

• Benjie Gillam's detailed protocol breakdown
  • Jonathan Leach's NodeRED work
  • Lawrie Griffiths' Github repository

Read this article on DesignSpark

More related articles can be found on the Arduino and Raspberry Pi Design Centers