The LTR-301 is just a photo transistor. As was said, with a 1k pullup, it will work about a foot but will not be what you expect from a remote. It will also have soft edges due to the open collector output and capacitance of the transistor. You could improve it by following with a comparator with a bit of hysterisis but you still won't get what you probably expect. IR Remotes are transmitted with manchester encoding (like PWM) on a low freqency carrier- usually 32Khz or 40 Khz- Sony is 40 Khz. This carrier allows the reciever to be narrow band and allow it to have a lot of gain without turning into a noisy mess. What you want is a IR Reciever module, these generally look like a photo transistor but actually have an amplifier, bandpass filter and data slicer in them which give a logic out- also with a pull up. Below is a link that is pretty good. IR reciever modules are not hard to find. I have some around here if you're in a time bind and need one today. Here's the link- https://faculty-web.msoe.edu/johnsontimoj/Common/FILES/sony_sirc_protocol.pd f
Regards, John M. Wettroth (984) 329-5420 (home) (919) 349-9875 (cell) _____ From: TriEmbed [mailto:[email protected]] On Behalf Of Shane Trent via TriEmbed Sent: Tuesday, October 20, 2020 10:03 PM To: Paul MacDougal Cc: TriEmbed Discussion Subject: Re: [TriEmbed] IR remote signals You need more pull-up. Use an external 1k pull-up and you should see the square waves. On Tue, Oct 20, 2020 at 8:37 PM The MacDougals via TriEmbed <[email protected]> wrote: See the attached scope shot. This is one mark from a SONY remote captured by an LTR-301 IR detector. https://www.sparkfun.com/datasheets/Components/LTR-301.pdf I have this device attached to an Arduino Uno and am using INPUT_PULLUP (internal pullup on the pin). I think that the wiggle on the scope between the cursors is the 40kHz modulation of the signal. The cursors cover 10 wiggles and the scope reports 4.04 kHz. My question is why is this wiggle of such small magnitude? I was expecting to see full voltage swing. Is it just this particular IR detector? Is there something in the datasheet that would indicate this? ---> Paul _______________________________________________ Triangle, NC Embedded Computing mailing list To post message: [email protected] List info: http://mail.triembed.org/mailman/listinfo/triembed_triembed.org TriEmbed web site: http://TriEmbed.org To unsubscribe, click link and send a blank message: mailto:[email protected]?subject=unsubscribe -- photo <https://d36urhup7zbd7q.cloudfront.net/90c0bf9d-3fff-46c1-b0e0-2d6ec5d88108/ ShaneBioPhotoCroppeddeleted19624a8551057e0d6dc353501de57e4d.crop_1536x2003_4 30,259.preview.format_png.resize_200x.jpeg#logo> Shane D Trent Patent Agent 919-348-0061 | [email protected] ShaneTrent.com | Skype: skype:shane.trent1 <> Raleigh, North Carolina <http://www.linkedin.com/in/shanetrent> <http://twitter.com/sdtrent> Create your own <https://www.wisestamp.com/signature-in-email/?utm_source=promotion&utm_medi um=signature&utm_campaign=create_your_own&srcid=5623268815667200> WiseStamp email signature
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