I am building a traffic light project with an Arduino Uno and I am planning on controlling the lights with pushbuttons. I have considered using a 4-position rotary selector switch, but this would only allow me to select which light turns on in the predefined order of rotation (for example, I would like to be able to select a green light starting from red, without going through yellow).
Does anybody know of a pushbutton switch that has mechanically interlocked buttons, so that when one button is pressed, the other buttons release? I know I have seen these types of switches before on pedestal fans (OFF-LOW-MED-HIGH), but I haven’t been able to find one to purchase. Alternatively, is there a way I can achieve this function with another type of switch?
I vaguely recall seeing something like what you’re looking for in an electronics catalog maybe 40 years ago… I spent a few minutes looking on Digi-Key without finding anything.
I have had a couple of thoughts that are potentially more helpful:
If you’re determined to have “new” parts, I’d suggest looking on a search engine such as Google for “small appliance parts”, and call one near you. (Be aware that they may quote a price that seems a bit high.) You could also look for “small appliance repair” places – one might have something in their “junk” pile that you could buy for not much and salvage the switch.
Another approach, if you’re not in a big hurry is to look for something with a switch like you want at yard sales and/or thrift stores. (This may be more difficult right now with the “social distancing” and such.)
The easier solution would be to use 4 regular pushbuttons with LEDs (either in the button or above/below it) and handle the interlocking in code - when a button is pressed, turn on its LED and turn off all the others. Keep track of which one is pressed and use that to select the sequence.
Thanks for the link and advice. I am working on a modification to the code so that I can eliminate the need for interlocking switches, but I’ll keep the link handy in case I end up going that route.
These used to be really common parts into the late 80’s but since micro controllers have taken over, they are getting harder to find since everything is done in code now.
Try the search term ‘interlocking push button switches’, that might get you in the right direction. I don’t know exactly how the part numbering works, but I’m pretty sure you have to purchase the switches and mounting/linking hardware separate and then assemble them into the configuration you need. Check [this switch as an example and have a look at the data sheet for the different switch and linking options.](F2UOA01AAU C&K | Switches | DigiKey)
microslide1:
Does anybody know of a pushbutton switch that has mechanically interlocked buttons, so that when one button is pressed, the other buttons release? I know I have seen these types of switches before on pedestal fans (OFF-LOW-MED-HIGH), but I haven’t been able to find one to purchase.
This kind of switch is commonly encountered on household blenders and, years ago, automotive radio tuner presets though those were mechanical.