Relay bypass kit that does 'momentary mode'

[disorder]

I was wondering if any of the fine PCB and kit suppliers like 1776, JMK, etc offer a relay bypass kit that does momentary mode. Like hold the switch in while applying power and it's in momentary mode. Or tap it quickly five times to enter momentary mode. I've been using the 1776 Finish Line relay board when I want relay switching but it doesn't have this feature.

I know Mr Bean offers the VFE switching board that has this feature but it is too big for my intended project. Looking for just the switch and the pcb with microcontroller and associated parts. Don't need the in/out and power jacks on the board.

Any clues?

[mjg]

If you're able to roll your own, you could probably do that without the microcontroller.  If you only want the relay to be switched when the button is pressed, you don't need the microcontroller to be maintaining the state. 

Just hook the relay +- pins from 5v, through your momentary switch, and then the other to ground. 

Of course I'm only thinking out loud here, so I could be totally wrong.

[WormBoy]

If you're able to roll your own, you could probably do that without the microcontroller.  If you only want the relay to be switched when the button is pressed, you don't need the microcontroller to be maintaining the state. 

Just hook the relay +- pins from 5v, through your momentary switch, and then the other to ground. 

Of course I'm only thinking out loud here, so I could be totally wrong.

I would say that would work, though you will be left with momentary mode only. TS might want to switch between modes ... Furthermore, it will likely pop in this configuration due to the nature of relays. You could make it a bit more elaborate by slowing down the voltage swing across the inductor in the relay: http://www.geofex.com/article_folders/rmtswtch/rmtsw.htm (built that one and it is noiseless). Not sure if the microcontroler code usually takes care of this slowing down ... if not, I guess that's the reason that I had popping with some of the PCBs offered ...

[mjg]

Yeah, it would be always momentary, so if you wanted to have it switchable that wouldn't do the job. 

That's a neat article about the relay popping, I'll have to have a go with that sometime. 

To get back to the original question - if you're happy with the 1776 effects board, there should be no reason why you can't reprogram the ATTiny chip on it to also handle momentary mode.  You'd need some programming experience, Arduino IDE, a programmer (an Arduino board will work, if you've already got one lying around), and it would depend on you being able to take the chip off the board, so hopefully it's socketed.  Of course, there are a lot of 'if's to this solution, but if you already have experience with Arduino it is an option. 

[kgull]

I've got some relay debouncing code up over here that can switch between toggle and momentary modes. Currently, it needs an external toggle to go between modes but I'm planning on playing around with this more after this semester is over (only 2 more weeks!).