5
\$\begingroup\$

I'm trying to build a device that is able learn a command from a TV IR Remote and recognise when this command is sent to it. I've see that the most common protocols used are NEC and Philips and that the frequency may vary of some kHz depending on the manufacturer. I need a receiver that is compatible with most of TVs.

The problem is the frequency: I've see modules like the Vishay TSOP48XX series but they only work with a specified frequency (like 36 kHz, 38 kHz, 40 kHz). Is it possible use these receivers out of their frequency range of 1 or 2 kHz with accettable results?

If not, what's the best solution in order to receive commands from all TVs?

\$\endgroup\$
1
  • \$\begingroup\$ Early remotes had a "Learn" button. Putting it head to head with another, could program the new remote. I have seen them available on ebay. \$\endgroup\$
    – Optionparty
    Commented Oct 5, 2013 at 7:15

1 Answer 1

Reset to default
3
\$\begingroup\$

Check the datasheet, it has a graph of the receiver's relative sensitivity versus the frequency. In practice a 36 kHz receiver will receive an 38 kHz just fine, but with a somewhat reduces maximum distance. AFAIK 36 and 38 kHz are the only really common frequencies.

Note that these receivers have an open collector output, so you could simply parallel a few different frequency receivers.

\$\endgroup\$
2
  • \$\begingroup\$ Thank you, I'll try with one receiver and then I'll make a decision depending on how good the receiver works out of range. Between 36 kHz and 38 kHz what the most used frequency? \$\endgroup\$
    – Oceanic815
    Commented Oct 4, 2013 at 16:38
  • \$\begingroup\$ IIRC Philips and its relatives use 36. Sony and relatives use 38. What's most common will probably depend on where you are in the world, here in the Netherlands it seems to be 50/50. I used to sell 37 kHz receivers, but my supplier no longer has that center frequency :( \$\endgroup\$
    – Wouter van Ooijen
    Commented Oct 4, 2013 at 19:59

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.