I have a little problem. I'm using the raspberry pi to send a output signal from the GPIO pins to activate / deactivate the relay. I have a IR remote, when i short the two "connectors" on (for example G1) on the remote together the control activates. But If I want to do it like this I would have to use two relays on each button. One relay for on(g1), and one for off(k1).

Is there a way to make it turn off and on with only one relay?


  • \$\begingroup\$ Do you have a schematic? What does "G1" mean? \$\endgroup\$
    – The Photon
    Commented Mar 25, 2013 at 21:50
  • \$\begingroup\$ G1 is a refrence to the placement on the board in the picture. All "on" buttons are labled G1,2,3,4 and "Off" buttons are labled K1,2,3,4. \$\endgroup\$
    – chriskvik
    Commented Mar 25, 2013 at 21:53
  • \$\begingroup\$ Cheaper way would be to use small transistors. \$\endgroup\$
    – AndrejaKo
    Commented Mar 25, 2013 at 22:20

2 Answers 2


Fundamentally, you need more than one device to control this system. You actually have 3 states, not 2: "send an ON command", "send an OFF command", and "send nothing". If you were to send the OFF command continuously whenever you weren't sending the ON command, it would be very wasteful of battery power.

So you inherently need two logical control bits and two switch devices to control the IR transmitter. As Andreja pointed out in comments, there might be lower-cost alternatives you could use instead of relays.


I would try to record the pulse code generated by the chip and send it by the raspberry. Normally the pulses are quite slow and easy to reproduce. The have no security or encryption. This way you need only a single IO.

If you want to use the control board: As far I have seen on the PCB, you need to pull the chip IO to GND to make it send. If you can join the 2 grounds, you could use a transistor to pull the pin down.simple pulldown transistor

The values in my schematic are not correct!


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