Hi Everyone, sorry if this is a complete beginner question....but I am a complete beginner!!
I've had some good fun with my Arduino and now I'm trying something a bit different.
The basic idea is to switch a 12v power source using a webcam's alarm output. Strictly speaking this isn't an Arduino question so sorry if a little off topic for this forum!
My webcam has an alarm output. It pumps out 5v when motion is detected. I want that 5v to switch a 12v power supply.
My relay module is the SainSmart 2 relay module, which I have had working on an Arduino project so I'm pretty sure it's good.
In my test setup I am using a AA 4 cell pack to mimick the webcam 5v input (reads 4.68v).
On the relay module I short Vcc and Gnd using the jumper. Then I supply the 5v trigger signal to Gnd and In1. VCC is not connected anywhere.
The signal LED on the relay module lights up, but the relay coil doesn't click on.
Would anyone be able to offer a stupid person like myself any advice please? Thanks so much if you can. Picture attached for reference!
benbenj:
On the relay module I short Vcc and Gnd using the jumper. Then I supply the 5v trigger signal to Gnd and In1. VCC is not connected anywhere.
I don't think I understand 5v to gound with no VCC and expecting it to work.
Unshort stuff.
Battery pack pos to module VCC.
Module GND to battery pack neg.
Touch 2nd battery pack pos intermittantly to IN1 and see if that switches the relay.
You know that VCC is the power and IN1 is the switch, right?
The way you are doing it is essentially like leaving the light switch in a room in the on position and then hooking and unhooking the AC to make the lights work. Usually one would hook up the AC (in your case DC VCC and GND), never touch them again, and then use the switch (in your case IN1).
You don't want the Webcam to power the relay. You want it to switch the relay using IN1.
Thanks Bigred1212. Yes I know it's a bit odd - but I do want the webcam to power the relay.
In my simple mind, that seems like the best idea because then I don't need another power source just for the relay. There isn't any other power in this project (apart from the 12v being switched).
It's working great....am I likely to break something doing it this way?
I don't know that you will break anything. The Webcam isn't a power source and if you are managing to power something through what I'm sure was intended as a 5v alarm/signal line, then I would categorize that as just getting lucky.
If it works, go with it.
If I were doing it I would take the Webcam signal into IN1 and find an additional power dource for the relay coil VCC, but that doesn't mean much.
