Hi Im new to the arduino platform and I would like to know if this project is feasible with one of these devices. Basically, I would like to monitor the status of 16 switches that are in series, their original purpose is to turn on/ off a relay when are all closed. I would then like to have the device turn on a green/red led to reflect the status of each switch, without affecting the original purpose of the series circuit. I can envision a common wire for the switch circuit, with 16 discreet inputs, and then 32 outputs for each red/green possibility. Basically if the switch is open, red light, switch closed, green light. When ALL switches are closed, only then would the relay operate. AND all green lights. Is it possible with 2 ore more of these? Or is this beyond the scope of arduino?
I know I have to consider electrical load, the leds dont draw much current, Im looking at one of these:
ok heres what I got so far, there are only a few switches shown for brevity, but the flaw is in powering the lights without affecting the end result. How do I connect 2 or more devices together as I would need 48 or more discreet inputs?
Larryd, I like this setup. Looks like each switch can control each light, Then I can program the device to turn on the main relay when ALL switches are closed? ANd is this scalable to 16 switches and 16 r/g leds? Or even separate red and green leds.
Tom, it isnt a safety lockout. I didnt want to get to wordy initially, but heres what it is. I work at a carwash, and we have a big commercial vac system with 16 drops in the express belt area. Each are fitted with a magnetic sensor type reed switch, all in series, so that when any one switch is open ( vac nozzle in use) the open circuit operates a relay to the NC state which connects the run command to a vfd, starting the vac. When all nozzles are docked, the circuit is complete, operating the relay to the NO state and shutting off the vac. This system saves electricity by not running the vac all day if not needed. THe project is to give a visual indication via an led (red/green) when the individual switch is open or closed. This makes diagnosis much easier as you will then know which nozzle is undocked (or switch bad) instead of going around with an ohmmeter. Problem is I need something to monitor the status of each switch (inputs, 16) and output to 32 lights( red.16 green,16).
Hi,
Okay, thanks, that will get the grey cells working.
What is the control voltage?
Are the switches individually wired back to the control area, or are they daisy chained across the washing bays so you only have two wires coming back to the control area?
yes everything is daisy chained. The circuit begins in the machine room at 12v dc, goes out to each drop, 2 wires each, then ends up at the relay back in the machine room. If 12 v dc is present at the end, then the relay turns on, switching the circuit off to the vfd which runs the vac motor. By default, i made it so that if any switch fails, or gets docked improperly, the vac would still run, just wont shut off. The goal is to monitor the status of each switch so in case of fault, you would know where to look. Just so that the monitor circuit doesnt affect the orig intention
