Power

The shield doesn't need external power: it will be provided by the base board, through the 5V and 3.3V pins of the Arduino board used as base.

INPUT and Output

The relays are controlled by the following Arduino board pins:

Relay 1 = Arduino pin 4

Relay 2 = Arduino pin 7

Relay 3 = Arduino pin 8

Relay 4 = Arduino pin 12

The shield features several TinkerKit input/output and communication interfaces. Connecting TinkerKit modules can simplify the creation of a project or a prototype. 

The on-board connectors are :

• 2 TinkerKit Inputs: IN2 and IN3 (in white), these connectors are routed to the Arduino A2 and A3 analog input pins.
• 2 TinkerKit Outputs: OUT5 and OUT6 (in orange), these connectors are routed to the Arduino PWM outputs on pins 5 and 6.
• 2 TinkerKit TWI: these connectors (4-pin in white) are routed on the Arduino TWI interface. Both connect to the same TWI interface to allow you to create a chain of TWI devices.