Hey everyone,
I have recently started using the Arduinos and by all means I am very new at all of this and am looking for some help an was unable to find it in the forums. I put together a system using One Arduino nano, 5v Pir, mp3 board, and one 4 Channel 5v relay board. The sensor triggers the nano witch then plays music and triggers all the relays creating a nice show. The problem Im having is that I want to change the sensor to the normal sized 12v pir sensors because there in a case, easier to handle and mount up nicely on a structure. The 12v pir sensor has 4 wires. " - + Trigger and trigger " where as the 5v sensors have " grd, power, sig" How can I make this upgrade? Iv tryed about everything I could find and think of and worried that I might blow it up. Please help if you can.
Thank you
The PIR may have voltage free contacts. Measure the R across the trigger pins.
Alarm system PIRs usually have a closed contact the goes open in alarm.
If this is what you have, treat it as a switch.
Weedpharma
Hi there,
Thank you for you message, although I'm afraid I may not understand how to use it as a switch. So I would power the 12v pir from its own power source (as im trying to keep the arduino at 5v because it seems to reset every time I hook the arduino up to 12v power supply) witch leaves me with two trigger wires an one trigger pin on the arduino. Are you saying to attach both wires together on the trigger pin? Or one trigger wire to the trigger pin on the arduino and the other trigger wire attached somewhere else?
Thank you again for helping me with this.
Before you connect anything to the Arduino, make sure you know what the outputs do.
If you have a multimeter, measure between gnd and each of the trigger pins. If you get 0v, measure resistance between the trigger outputs when the PIR is standby (open) and triggered (closed).
If this is all true, you can simply use the trigger pins as a switch. This means connecting the terminals between a digital input and gnd with a pull up resister.
If you do not have a multimeter, get one. They are cheap and will be used a lot if you continue with any electronics.
Weedpharma
Hi there,
So here is the update. I checked the PIR trigger wires with the pir ground and there was zero voltage both on standby and when its triggered. With that being the case I now need to hook this up to my trigger pin on the nano, but I have two trigger wires and im unsure how to hook them up as a switch like you mentioned. Should I take one trigger wire and hook it to the trigger pin on the nano and the other trigger wire share a ground with the nano? Also what is a pull up resister? Sorry im such a newbie on this.
Thank you again for your time.
I also ask that you check between the trigger outputs. I expect there will be a short that will open on alarm.
This indicates a relay contact.
To read its state you connect one trigger wire to ground of the Arduino and the other to a digital input. The input needs a pull-up resistor to stop the pin from floating. This can be a 10k resistor or use the internal pull-up.
Alarm outputs are normally closed so your code needs to look for a high when in alarm.
Weedpharma