does anyone know of a 16 to 4 line encoder and part number? It can be either cmos or ttl. I've searched google and here and didn't come up with anything. If something exists like this please let me know.
Not sure on the more than a single high part. Basically looking for something like a BCD encoder or a 10 to 4. I'm actually just looking at using 12 of the inputs, not all 16.
does anyone know of a 16 to 4 line encoder and part number? It can be either cmos or ttl. I've searched google and here and didn't come up with anything. If something exists like this please let me know.
I've seen the 74C922 on the University of Toronto PIC demo board. You can still get them but they cost more than a PIC 16F628A would (that could replace it, and offer more features too like key rollover and buffering) and enough I/O left over for a buzzer
I've seen the 74C922 on the University of Toronto PIC demo board. You can still get them but they cost more than a PIC 16F628A would (that could replace it, and offer more features too like key rollover and buffering) and enough I/O left over for a buzzer
hi Bill,
I would agree they are expensive, I wouldn't recommend them for a new design.
However, I have seen 2 or 3 members asking for information on the ic.
It reminds me of the robust business on E-bay for Nixie tube displays. Seems that many want to build digital clocks using these old displays even though it's really old tech and can take quite a few bucks gathering all the high voltage parts and such. I use to have tons of that old stuff around but somehow between home moves most is gone. Still have lots of mid 80s and on stuff.
I'm using it to encode 12 pushbuttons into a 4 bit code. It's not for a keypad per say but something similar. It's just going to take the 12 pushbuttons and make it into a 4 bit binary value so that it can be used with less traces to be run, etc on a pcb.
Obvious method would be to use a PIC to do it, and either run four traces as planned, or even one as a simple serial interface. You've not mentioned what the rest of the project is?, but it's probably also simpler to replace the rest of it with the same simple PIC? - or a couple of them?.
I really don't have any experience in PIC work. I've been thinking about diving into that world, but really don't know what type of programmer chips etc would be a good starter kit.
I pretty much know when I get into that, I'd want to use flash based PICs for learning on so I can play around without spending several dollars per chip. If you happen to know of an easy programmer to learn on, please feel free to recommend one. I'd like to try to stay under $50 for a whole kit (1 flash chip, programming hardware, and software) if possible.