Hi - I'm one of the developers of PayPal Here, our card reading mobile app. What you're describing is in theory possible, though you'd pay the "card not present" rate (3.5% + $.15 in the US) because you're using an unencrypted crappo swiper. But we do have APIs that would let you do this. In theory you could use our reader too, but then you'd have to reverse engineer the audio interface which would be a pain in the arse. It would be a cool demo though, so if I can provide help, I'm happy to.
It now seems that the best solution is to simply have paypal buttons put on the my site that they can click instead of the whole card-swiper thing.
What I'm asking about is essentially the same thing as a sun tracker.
except it will need to follow an IR LED or small cluster of LEDs and be much faster on the response time. I know the servo can move much faster but maybe there is something else limiting the speed like the response time of the phototransistor. Do any of you with experience with this stuff think that it will be able to work with those modifications?
Ok let's think this through. You have two photoresistors focusing on one source, and you want the turret to line up with that source, correct. Regardless of what's on the turret, you want to make it so the turret is pointing directly at the source.
Well, being that you will be receiving readings from the photoresistors, in order to find the center of the two, you will need to compare the two readings and turn accordingly.
If that is the case, it is extremely simple to do. If that's not the case, then your not clearly explaining what you want to do.
yea, that's all I'm trying to do. I want to know how far away the IR LED will be detected though. If I can't make it work at 100ft or so, then it's not worth pursuing.
What are the other environmental sources of IR light in an office environment?
Well, it's a 150 million kilometres away, but it's a biggie.
If they exist, then where is an IR LEd emitter/detector pair that use a spectrum that is not typically found?
Illuminators used for IR number plate recognition systems are necessarily heavily filtered to eliminate environmental IR.
Come one man. This is indoor only. I know the sun would totally mess it up. The things you're referring to are all outdoor issues. Let me be even more unnecessarily clear; In a gigantic, building sized box, with fluorescent lights, how far away can a slowly blinking IR led be to register a change in value on the IR receiver as it blinks on and off?
I just want a response from someone who has already worked with these parts.
Which parts? You haven't specified any parts.
You're being unnecessarily picky. The level of detail you're asking for isn't relevant but just so you can get over this mental block, here are parts for you: http://www.radioshack.com/product/index.jsp?productId=2049723 They don't matter though because the difference between these parts and other IR phototransistor and IR Leds of the same size is obviously negligible.