Is there any way we can control 2 arduino pins with a single light switch?


I m trying to reduce the use of pins used on arduino uno so that i can connect more sensors. I plan to use a 1 by 4 demux IC which uses 2 select lines. so with just 2 pins i can connect 4 loads. I’m new and i dont know how to use it that way. Any advice will be valuable. Thank you


How many sensors you plan to connect?
I know two methods for increase the possibilities - Second MCU or Multiplexing.
Also you can use some ready shields?


wish to connect as much with a single uno


You can use OneWire and connect as much you want temp sensors for example :slight_smile:


Yes, but i want to know whether there is a way to control multiple digital pins via single actuators.:grin::relaxed:
Like press a light switch get 2 led’s off or one ON and another OFF


I think that you can. I am posting some code, please note that I might miss something, but I show how I command two relays with one widget and one virtual port :slight_smile: I hope you catch the logic!

#define VIRTUAL_BUT V6

char token[] = "AuthenticationToken";

void setup()
  // set digital pin to output

void loop()

  // read the integer value which should be 0 or 1
  int enabled = getValue.asInt();
  if (enabled == 1) {
    // turn both motors on
    digitalWrite(RELAY1_DIGITAL_PIN, HIGH);
    digitalWrite(RELAY2_DIGITAL_PIN, HIGH);
  } else {
    // turn both motors off
    digitalWrite(RELAY1_DIGITAL_PIN, LOW);
    digitalWrite(RELAY2_DIGITAL_PIN, LOW);


tried it and its awsome awsome awsome, thanks a lot :grinning::sunglasses:


Just to know, what does the “CAYENNE_IN” do?
is there any thing similar to this?


CAYENNE_IN(vPIN) CAYENNE_IN defines a function that is called when the device receives an updated Virtual pin value from the Cayenne server.

For more information, you can visit Docs -> HERE