Smart Relay Shield

The primary purpose of the SRS is to provide the ability to programatically switch mains voltages. This has already been achieved by relay shields for the Arduino form factor for mains electricity supplied at 110V AC. Mains circuits in Australia are designed to supply a nominal 230V 50Hz AC therefore the 110V relay shields are not suitable. The objective was therefore to produce a similar design centred around a 240V AC 10Amp relay unit.

The serial command mode interface is where things get interesting. This requires some form of smart controller on the relay shield to interpret the commands given over the serial interface. This does increase the complexity of the device but it also opens up some interesting options. With the addition of a serial to USB interface the Smart Relay Shield can be connected to a PC. The same serial interface can very easily be connected to just about any simple data radio. The on-board processor can reduce the load on the Arduino – the Smart Relay Shield could be instructed to carry out a sequence of operations and the report back to the Arduino on completion. If the Smart Relay Shield were easily expandable then the options are just about limitless.

Features

• Provide control for 4 240V AC 10A relays.
• Arduino compatible
• A choice of 4 pin direct digital control or serial interface control.
• Capable of off line control – independent operation.
• Designed to be expanded or augmented.
• XBee Serial interface

Photos copyright Adrian Carter.