Freetronics 8-Channel Relay Driver Shield
Shield URL: 8-Channel Relay Driver Shield
Tags: relay, output, i2c
Drive up to 8 relays from your Arduino using just 2 I/O pins. Communicates with your Arduino using I2C, so you can stack several shields together to drive 16, 24, or more outputs.
I2C connections are linked by default to Arduino pins A4 and A5, but can be switched to use the R3 headers using solder jumpers. This allows the shield to be compatible with older R2 boards such as the Duemilanove, newer ATmega328P boards with R3 headers such as the Uno R3, and non-ATmega328P boards with R3 headers such as the Leonardo.
Includes back-EMF protection and works with a wide range of relays.
Relays can be powered independently from your Arduino, or the relay power rail can be jumpered to Arduino VIN to allow the Arduino to be powered via the shield or vice versa.
Screw terminals for connecting to relays are located outside the Arduino header profile to provide easier cabling access.
Open Source: Yes, OSHW-compliant
License: TAPR Open Hardware License