One thing I have noticed with a number of the low-cost infrared dongles for Apple and/or Android devices, is that the app (and hardware) developers assume a carrier frequency of 38kHz, even when the learning function is used.
You may know this, but use of a 38kHz carrier for devices which do not use a 38kHz carrier e.g. Philips (36kHz) and Sony (40kHz) would result in degraded infrared reception performance.
I even observed that a USB OTG dongle (ZaZaRemote) has USB and infrared inputs and outputs connected directly to the microcontroller (Silicon Laboratories C8051F326 - 25MHz) only outputs a 38kHz carrier, despite selecting Philips or Sony codes with the related app (and that it had a 38kHz infrared receiver module for learning), although I did observe another dongle (Tasogo) which supports carrier frequencies other than 38kHz.
One concept you should be familiar with: carrier frequencies
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One concept you should be familiar with: carrier frequencies
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