Momentary switch button array control

[mth5044]

I'm looking to control a 4066 or similar device with these momentary switches:

http://www.sparkfun.com/products/7836

I've looked at the ToneGods' wicked switches and RG's article on similar switches, however they all involve controlling the entire switch as one single flip, instead of each internal switch by itself. The goal would be to control 8 latching SPST switches using 8 momentary SPST switches linked above (switching signal)... plus LED for each switch.

Perhaps the FET type switching also detailed by RG here:
http://www.geofex.com/Article_Folders/bosstech.pdf

~arph had used a microcontroller to control a similar array, and CG had been working with me to make a code and print it, however the price point was too steep for me.

Any simple ideas using CMOS? Thanks

[R.G.]

I'm a little hazy on what you want to do. Do you want each momentary switch to be independent, causing its own light to go on and off independently of all the others? Or do you want any one switch to turn itself on and any others off?

There are CMOS approaches for each one of these. The independent latching case can be done with CD4013s (two switches per IC) and the one-of-eight case can be done with the 74C373 as in my programmable footswitch article.

The uC approach can do either, or if you are clever with programming, switch between the two styles, even on a switch-by-switch basis. The uC is probably cheaper, as a suitable uC costs about $2. The programming is the problem. The CMOS devices will be nearly that much, or more.

[Earthscum]

This would be my solution, if I'm understanding you right. This is 2 switches using:
Resistors and caps,
2X CD4049 (or schmitt trigger, if you prefer)
1X CD4066
4X JFET
4X LED
4X Momentary (NO) pushbutton switches

A pair of these will get you 8 SPST switches

[mth5044]

RG - I'd like the switches in the array to be independent of all other switches. You'd be able to have all switches on, off, or any combination within. I'll have to look into the 4013 approach, thanks. I'm not looking into getting into programming the moment, so the uC approach won't work for me at this time.

Earthscum - that is exactly what I was looking for... seems easy enough too. Thank you!

[R.G.]

E.S.'s solution works. The two inverter thing makes a T-type flipflop. I might do the LEDs a different way. Since the CMOS gates doing the logic are not hugely sensitive to loading, I might run a resistor to a high gain NPN or a darlington inverter instead of a JFET as in the Millenium 1. But that does work.

[mth5044]

Finally got around to working on this.. but it seems I have overlooked a bit of the switching array. The switching array I had mentioned in my first post actually has all four of the 'power' side of the switches connected together, and separate grounds, as per this schematic:

http://www.sparkfun.com/datasheets/Components/Buttons/2x2Button_Pad_Breakout-v01.pdf

Is there any way to use the same basic layout that Earthscum provided, but work around this little hurdle? I suppose I could just cut the traces and solder to them, but they are pretty tiny.

[mth5044]

Perhaps have the connected sides have the same cap to ground, then stem four resistors off the side to each switching circuit?