So I want to add a battery and a 433mhz transmitter to that foot switch and for the receiver I would like to get a board that can be powered from USB and can switch 2 relays via 433mhz. This one for example.
The obvious issue is that the remote would only toggle the relay, meaning I would have to press the push button twice. And it's also very possible that one button on the handheld remote is for switching the relay on and the other button is for switching the relay off. I don't even know if I could toggle the relays on that board separately. So I might have to get this one instead
Any ideas how this could be done in a way that the transmitter doesn't use much power? (i.e. could run on a coin cell battery) (Only the receiver will be connected to a power bank.)
Edit: Timing is kinda important btw. So ideally the pushbutton would not send the release signal before it has actually been released again.
I realize that, the question is how because just connecting the footswitch buttons to the handheld remote buttons wouldn't be enough.
When the footswitch button is pushed it somehow needs to do a push+release on the remote. And when it's released it needs to do another push and release on the remote.
And using a microcontroller would mean way too much power consumption.
I bet there is somw sort of complicated circuit involving transistors and capacitors or a timer ic that would allow me to do what I want, but I'd have no clue on how to do that and maybe a pcb for that purpose already exists.
I would like to get a board that can be powered from USB and can switch 2 relays via 433mhz. This one for example .
I've had a read of the information on that listing, and it seems like it will do what you are looking for. There are "mode selection jumper pins" underneath the board. When none of these are shorted, the device is in "jog" mode.
"Jog" seems to be a slightly obscure term for "momentary ON". When A is pressed, relay A will connect. When A is released, relay A will release.
I was posting under General Electronics. That seemed like the most fitting one looking at other threads posted in there.
I don't know how the remotes work, but my concern is power consumption, that's why I think an Arduino is not the right tool for the job. It would seem like some sort of flip flop circuit would be a smarter way to solve this unless of course there is a simple way to reprogramm the remote's microcontroller (if it has one).
@toddnz I think it's more likely that the momentary ON mode will turn the relay off automatically after a fixed amount of time because I don't think that these handheld remotes send separate signals for push and release. But I could be wrong.
I opened the remote and desoldered the buttons and battery connectors. Then I soldered the footswitch buttons to the remote's PCB using some wires. Then I soldered the 12V A23 battery to where the battery connectors used to be. (Soldering to a battery requires a fairly strong soldering iron and plenty of solder. A battery holder might be a smarter way to do this.
I also opened the receiver drilled a hole into it and screwed in a standard DIY TRS connector. I then soldered the connectors 3 pins directly to the relays on the PCB, so that I don't have any wires exposed to go to the screw terminals.
For the 5V input terminal I simply screwed in a micro USB breakout board. It was also necessary to remove the jumper from the receiver PCB as @toddnz mentioned.
I'm not sure how much power the receiver draws. It might be feasable to add a small 500mAh lipo battery, with a charging board and power switch to it.
The transmitter only draws power while a button is being held down and can probably do thousands of cycles.
