Simple Relay Shield for Arduino




Introduction: Simple Relay Shield for Arduino

Shield to control 6 relay, 6 digital input and 6 analog input with Arduino Duemilanove, Arduino UNO. The digital inputs and relay outputs are equipped with an LED that indicates the status. 
The circuit diagram is very simple:

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Step 1: Schematics and PCB

In this step you can find the circuit diagram and the PCB file. 
All the digital input are protected by a diode, the analog input are protected by a zener diode.

BOM Arduino - IN/OUT

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

- 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

Step 2: The Simple Code

You can also manage the I / O loading in the Arduino the sketch downloadable from the web pages or With it you can manage the inputs and outputs directly from a graphical interface, through processing.
Another Sketch is pubblished on the site
This is the site where my company publish the open source projects.

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    13 Discussions


    4 years ago

    Nice Job! please share the Egle files or gerbers for this PCB design, so we can use it for UNO expansion. Can't do it with the PDF files. BTW, replacing relays with required matching coil voltage is easy...just put the right voltage at +V pin seperately...isn't it?

    José Luisd10
    José Luisd10

    Reply 1 year ago

    1.Buenas tardes quería saber si dispone el pcb del circuito en tamaño real para enviarme.Desde ya le agradezco su respuesta

    José Luisd10
    José Luisd10

    Question 1 year ago

    1.Buenas tardes, muy buen trabajo, quiero consultarle si dispone el pcb en tamaño real para enviarme. Le agradezco su pronta respuesta.Un cordial saludo


    4 years ago

    What should be modified to work with digital inputs and relay 24v ??


    6 years ago on Introduction

    please give me a pcb file (PDF) or egle file, i can't print pcb frome picture


    8 years ago on Introduction

    Nicely laid out board. Could be just what I need.  I need to know two things:

    1.  How much AC current can each contact take? I want to use them to switch 100 W lamps on and off . 

    2.  Can the relays pick at 5V?  I wish to run my arduino and the relay shield off of an old cell phone battery charger, rated 5.6V, 300ma.

    Why is it that no one seems to be making 6V relay shields these days?  

    When possible, I prefer to use cell phone battery chargers because they are tiny and rated for long term use.  Much better than lugging a 12V power supply around and burning off the excess voltage with regulators.


    Reply 8 years ago on Introduction

    the small relays don't support high voltage, but you can use them to drive other relays.
    You can use 5V relays but you have to change the PCB.


    8 years ago on Introduction

    Very well laid out . Very nice the way you placed a lot of components into a small area. Keeping all the output contacts together on one side of the board is great for isolation as well. Thanks for the ible !


    Reply 8 years ago on Introduction

    :-D Thank you zazenergy.
    Now I'm working around a GSM Shield using low cost SIMCom module....