I am looking to get a few red LED matrix's and I found a cheap one here:
The thing though is that this has 24 pins but it says it is a single color. Normally, this should only have 16 pins so I am wondering what the extra 8 would be for. If it was a dual color matrix I would understand but with this situation, I am a bit confused.
Is it common to have extra, unused pins on matrix's like this or am I reading this thing wrong?
Edit:
One other question. I have never bought one of these before (always made my own matrix) so I am wondering what kind of viewing angle these can be seen at? Do you have to view them head on or is there a decent angle (maybe 30-40 degrees) that they are still well visible?
shiznatix:
The thing though is that this has 24 pins but it says it is a single color. Normally, this should only have 16 pins so I am wondering what the extra 8 would be for. If it was a dual color matrix I would understand but with this situation, I am a bit confused.
I think you guess right. Currently, bi-colour units are the most commonly used, this is from a production line which makes both, so they use the same setup.
shiznatix:
Is it common to have extra, unused pins on matrix's like this or am I reading this thing wrong?
Yes. Some of the units I have, notably those used in the JY-MCU Lattice Clock which is quite worth considering in itself and has a fair bit of support, are as you describe 24-pin units and obviously have only the red LEDs loaded on the frames with an evident empty position for the green set - as I suspect you will find if you examine yours.
shiznatix:
what kind of viewing angle these can be seen at?
Excellent - by dint of the "light pit" design, good visibility to about 160° or more.
shiznatix:
The thing though is that this has 24 pins but it says it is a single color. Normally, this should only have 16 pins...
I always check description and photo before buying, but it wouldn't surprise me if you'd get a 16-pin version If you would buy one. With all those millions different components, maybe someone added some photo's of a... led-matrix, thinking it was the right one.
Ok, so no need to worry. I went ahead and purchased them so I will see what the reality is soon (well, probably in like 3 weeks but thats how it goes).
I don't know whether you'll get a 24- or a 16-pin matrix. It wouldn't be the first component sold with the wrong picture in the advertisement though.
I'd look for a 16 pin version (on photo as well) if I would only need a single colour. If you would buy a 24-pin single colour version, it may be hard to replace if it breaks down.