I am looking for inexpensive keypads to use in class. I need between 12 and 25 units so low price is important. I have checked at electronic goldmine, allelectronics, alltronics, and mpja. The only real canadate so far is this membrane unit. From alltronics.com for $1. There is noi nfo regarding what if any electronics it contains. It looks like the cable has nine conductors which would make sense for a 4x5 raw matrix.



If you know of a better unit at about the same price or some reason to stay away from this one I would like to know.

Thanks 3v0

I don't like membrane keypads, they are much too unreliable - if you only want 3x4 or 4x4 numeric/hex keypads (as used in my tutorial) I've seen them for sale (and bought some) at Radio Rallies, something like four for £1.

That would be nice but I do not have access to such events. The nearest is quite possibly 200+ miles away and held once or twice a year. I need to be able to order them.

I have been looking at ebay without much luck. Found some interesting USB and PS2 keypads in that range but I would like a simple matrix for teaching.

3v0

Originally Posted by 3v0

That would be nice but I do not have access to such events. The nearest is quite possibly 200+ miles away and held once or twice a year. I need to be able to order them.

There must be plenty of surplus places selling them in the USA, just a question of finding them (which is why you asked here of course).

Originally Posted by Mike, K8LH

That membrane unit actually looks pretty nice. Have you thought about calling them up and explaining your needs? Perhaps they'll send you a sample to try out...

Good luck. Mike

Good idea. All they can say is no. Or maybe I can find a few things I need from their site and shell out for one or two of the keypads to try.

EDIT;
Over here the Radio Rallies are Ham Fests. The people I have talked to say most of the good stuff is going to ebay. But ebay has been increasing their cut so maybe that will change.

Originally Posted by 3v0

I am looking for inexpensive keypads to use in class.

Try BG Micro. Can't touch $1 each, but...

3V0

Just did a search myself and can not believe they are none out there. But it sure looks that way. All the good surplus spots you mentioned did not even popup in the search.

I guess they get them in waves as R&D shops go under or people unload old inventory. We used to use them on units and I nabbed a few when we shut-down (with permission of course). If I can find them they are yours if that helps, but I think I had 4 or 5, berg pin type so they can plug into a proto board. Hard plastic with chiclette plastic buttons.

I've been doing a similar search for a few weeks, and have not found anything less than 3USD. As you've seen, allelectronics/electronicsgoldmine have a 3 dollar pad, but the one I got had to have pads/connections resoldered before I could get it to work - very cheap stuff. The others at about 5USD/pc were fine, nothing special.

I recently gave in and bought 20 membrane kpads for 100USD from an ebay seller called Bob Xiang Xi or something similarly comical. That was a special bulk price he offered me.

The ironic thing is that those USB enabled numeric keypads are as cheap, if not cheaper, than plain/generic/bog-standard keypads. Perhaps you should consider those and just hacking into the keypad part, ignoring the USB stuff.

A QWERTY w/ simple connectors for 2USD/pc

12KC132A 26S06621-KEYBOARDS (W/CONN 2 PCS PER) SALE!!!


I wish you luck, please report back if you find something spectacular.

eBay Store - PIC-Projects: Keypads: DATA KEYPAD 3X4 White White KEYS 3 4 Switch Key x

Any good? I'm sure he would be iwlling to ship to the US

A bit on the spendy side in that I needed a few of them. I took the plunge and ordered the alltronic units I posted about earlier. The min order was $15 and the shipping $11 (a bit high) so I ordered 20 of them.

Thanks everyone.

3v0

Originally Posted by Blueteeth

eBay Store - PIC-Projects: Keypads: DATA KEYPAD 3X4 White White KEYS 3 4 Switch Key x

Any good? I'm sure he would be iwlling to ship to the US

You may not be too too late.

I have the keypads from alltronics and I am not sure I can make them work for less then the cost of the futurlec units.

The problem is the connector. I was thinking I could tack small wires to the traces on the flexi-pcb, but as soon as the soldering iron touches it the plastic melts. If I could find the right female connector (not sure what they are called) that would work but I am thinking it will be more then the keypads are worth. For about $20 plus shipping I can get conductive glue but that has the same problem.

I could make home-brew connectors. A PCB with matching stripes and a 2nd blank board to hold the sandwich together but I do not think I want to subject the kids to that.

Originally Posted by Daniek

I guess I'm a bit too late now, but futurlec has got 3x4 some tactile switch type keypads for $2,20.
Keypads

Daniel