Infrared signal strenth

Need Help With My Project
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18

Okay, here are my thought…

  1. The IR LED that you’re using as your transmitter to the AC may be operating on a different wavelength to the LED of the original remote and the receiver built in to the AC unit. Have you bought different wavelength IR LEDs and tried them?

  2. IR remotes often send the command in a sustained burst that repeats the same command multiple times. If you’re sending it just once then it may not be being received as well. Some systems have some error checking built in, which require the same signal to be received multiple times within a certain time frame, so if you are sending the signal multiple times then either the timeframe may be too long or the number of repeats may be too short.
    You can often do tests with the IR sniffing software and the original remote, when used alongside the AC unit to work out how many times the same signal has to be sent before the AC unit will accept the command.

  3. You can use reflectors like the one below to focus the IR light from the LED so that more of it reaches the AC unit. Obviously aiming becomes more critical, but provided your transmitter is in a fixed location then it shouldn’t be difficult to do. You could use a visible light LED to help if you wished.

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F173684562154

  1. You could use multiple IR LEDs to give more power.

  2. It looks to me like the IR receiver on the AC is probably behind the little grille at the 12 o’clock position. It looks a little bit obscured to me, maybe there’s a way to make it more accessible without it looking rough?

Personally I think point #2 is worth investigating first.
I have some blinds that are operated by a 433MHz remote and I spent a lot of time sniffing the protocol and reproducing it, only to find that the command needs to be received at least twice for it to be auctioned and sending it four times in quick succession is the most reliable way to make sure that it’s ‘heard’ by the blinds.

Your setup seems quite similar to what I’m doing here:

Pete.