Relay Shield for Arduino

The card can be used to connect Arduino to users that need to be galvanically separated from it (such as small electric motors) and read signals of sensors or switches that may present impulsive noise or voltage spikes that might damage the microcontroller ATmega without adequate protection.
The management of the relays and the acquisition of digital and analog input voltages can be made using simple software or firmware routine generic ready, you can also control the Shield with Personal Computer, in fact, the Arduino IDE has a terminal emulator (a sort of Hyper Terminal of Windows) that allows the sending and receiving serial data to the card and then the direct management of the relays from your PC and input. Sending via serial (set for 9600, 8, N, 1, or speed of 9600 bps, 8 bits, no parity and one stop bit) followed by the command or channel number, it activates the corresponding relay, for example, O2 activates relay 2. The intended function of the outputs of the bistable type (toggle) and then inverts the status of each command on the relay. With the command Ix (where x is the channel number) requires the state of a digital input, with the command Ax test the analog input.
For each command, the module Arduino terminal emulator responds with a message that indicates the output status due to the control, or the state of the object of the command. For example, by issuing the command O2 you can get “Out 2 = 1”. Similarly, for the inputs we have messages like “In 3 = 0” in the case of digital or analog input 1 = 126 when it comes to analog input, in which case the value following the equal sign is the equivalent under ‘A / D converter.
You can also manage the I / O loading in the Arduino microcontroller the sketch downloadable from the web pages http://arduino.cc/en/Reference/Firmata or http://firmata.org/wiki/Main_Page. With it you can manage the inputs and outputs directly from a graphical interface, through processing. Processing is a language that allows you to create a variety of applications (with Arduino sketch) and in this case we can use to draw the sketch signed, which is located directly between the examples of the Arduino IDE and we will need to operate input and relay the our board. This sketch should be amended slightly, just to “say” to Arduino which pins are connected to which outputs and inputs, then everything will work smoothly.

R1: 1 kohm
R2: 1 kohm
R3: 1 kohm
R4: 1 kohm
R5: 1 kohm
R6: 1 kohm
R7: 4,7 kohm
R8: 10 kohm
R9: 4,7 kohm
R10: 10 kohm
R11: 4,7 kohm
R12: 10 kohm
R13: 4,7 kohm
R14: 10 kohm
R15: 4,7 kohm
R16: 10 kohm
R17: 4,7 kohm
R18: 10 kohm
R19: 470 ohm
R20: 470 ohm
R21: 470 ohm
R22: 470 ohm
R23: 470 ohm
R24: 470 ohm
R25: 4,7 kohm
R26: 4,7 kohm
R27: 4,7 kohm
R28: 4,7 kohm
R29: 4,7 kohm
R30: 4,7 kohm

C1: 100 µF 25 VL el
C2: 100 nF

D1: 1N4148
D2: 1N4148
D3: 1N4148
D4: 1N4148
D5: 1N4148
D6: 1N4148
D7: 1N4148
D8: 1N4148
D9: 1N4148
D10: 1N4148
D11: 1N4148
D12: 1N4148

DZ1: Zener 5,1V 400 mW
DZ2: Zener 5,1V 400 mW
DZ3: Zener 5,1V 400 mW
DZ4: Zener 5,1V 400 mW
DZ5: Zener 5,1V 400 mW
DZ6: Zener 5,1V 400 mW

LD1: Led 3 mm red
LD2: Led 3 mm red
LD3: Led 3 mm red
LD4: Led 3 mm red
LD5: Led 3 mm red
LD6: Led 3 mm red
LD7: Led 3 mm green
LD8: Led 3 mm green
LD9: Led 3 mm green
LD10: Led 3 mm green
LD11: Led 3 mm green
LD12: Led 3 mm green

T1: BC547
T2: BC547
T3: BC547
T4: BC547
T5: BC547
T6: BC547

RL1: mini relay 12V
RL2: mini relay 12V
RL3: mini relay 12V
RL4: mini relay 12V
RL5: mini relay 12V
RL6: mini relay 12V

Misc:
– Screw connector 2 via 2,54 mm (8 pz.)
– Screw connector 3 via 2,54 mm (6 pz.)
– Strip 8 via 12 mm (3 pz.)
– Strip 6 via 12 mm
– PCB