how to match IR parts
Jayguy5000
Posts: 139
I have on hand some IR receivers and led's. the receivers are 40Khz and the led's are 850nm. That is all the information I know about them. I do know that the BS2 IR detector is 38.5Khz and the led is 980nm. I am wondering If I can use my peices instead of what came with the boe bot kit, or how do I figure out how to match IR. Even better, do you have a link to something that touches on this topic in depth enough for me to figure all of this out? I have done a bit of searching and came up empty so far. The more info the better!
http://www.project-parts.com/data/tfms5400.pdf <~~~that is a link to the data sheet, I have the 5400.
P.S. I am hoping I can use my 850nm IR led and just put 40Khz through it instead of 38.5Khz, and then the receiver should be able to pick it up, however I am afraid the receiver is also set to receive only a certain wavelength of light be it 850nm or 980nm or something else. Thanks for the help.
The reason I want to use my pieces is because I have about 100 of each and 0 of what came with the kit. I just want this for some simple distance detection, will not be transmitting any data.
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Actually I think Im going to add the whiskers to my tank and let it roam, just need to figure out where.
Post Edited (Jayguy5000) : 3/6/2009 1:39:29 AM GMT
http://www.project-parts.com/data/tfms5400.pdf <~~~that is a link to the data sheet, I have the 5400.
P.S. I am hoping I can use my 850nm IR led and just put 40Khz through it instead of 38.5Khz, and then the receiver should be able to pick it up, however I am afraid the receiver is also set to receive only a certain wavelength of light be it 850nm or 980nm or something else. Thanks for the help.
The reason I want to use my pieces is because I have about 100 of each and 0 of what came with the kit. I just want this for some simple distance detection, will not be transmitting any data.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Actually I think Im going to add the whiskers to my tank and let it roam, just need to figure out where.
Post Edited (Jayguy5000) : 3/6/2009 1:39:29 AM GMT
Comments
Parallax's receiver's datasheet has a graph showing the sensitivity of the device vs. the received frequency. Parallax's use of IR for distance detection makes use of this sensitivity curve and they vary the transmitted frequency to adjust the effective sensitivity of the receiver, thus gets a reading on the strength of the received IR signal.
The datasheet should also indicate where the peak sensitivity is to IR wavelengths and may show the fall off in sensitivity with change in wavelength, thus give you an idea of whether your devices will work with each other.
Figure 12 on your datasheet shows the Spectral response (like to an 850nm IR signal) and Figure 1 shows the response to different modulation frequencies.
You'll be able to modify the BS2 code for the different modulation frequency for transmission, but you'll lose 80% or so of the signal due to the different IR wavelengths involved.
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- Stephen