How should I receive and send Raw IR code for my app?

[ItaiCuker]

Will resultToRawArray(&results) work for every IR code I receive?

For my senior year of HS, I am developing an Android universal remote app with the ESP32 and this library. I am trying to simplify so I won't need to work with protocols, will it be possible to make this pseudo-code work for a fair amount of IR codes?
I am using Google Cloud IoT core and firebase in my project if anyone is curious.

1. server sends ESP32 read IR code command
2. User points remote at ESP32 and holds button until he gets an alert that ESP32 received IR code
3. ESP32 uploads IR code to server for further usage.

Further usage - The user presses a button on the app that makes the ESP32 send the saved IR code.

How can I be sure that the IR code I received will work for any remote?

[NiKiZe]

It depends on the quality of received signal, and it also takes more space to store that way. But yes the array of timings is usable.

[crankyoldgit]

Your Universal IR app will encounter some issues.
Namely, you can't tell the modulation frequency of an incoming message when using an IR demodulator (like this library requires). 90%+ use 38kHz, but some devices use different ones. E.g. From memory: Sony (40kHz), Panasonic (57.6kHz) etc.
Another aspect of the incoming message that is lost is the Duty Cycle used. sendRaw() assumes a duty cycle of 50%, some protocols use 25 or 33%. Though, unlike the modulation frequency, this seldom matters.

To give yourself a head start, look at the following code examples:
https://github.com/crankyoldgit/IRremoteESP8266/blob/master/examples/DumbIRRepeater/DumbIRRepeater.ino
&
https://github.com/crankyoldgit/IRremoteESP8266/blob/master/examples/SmartIRRepeater/SmartIRRepeater.ino

You will notice they both use resultToRawArray().

[ItaiCuker]

I tried both examples you suggested and got the same output and input when observing using my oscilloscope

Osciliscope sniffing IR modulator:

Osciliscope sniffing IR emitter:

I tried both examples with different baud rates and buffers. My emitter is using a transistor but the output is not correct even when sniffing outside the IR emitter module.
The Remote I am using is for a Midea A/C and the program knows it as Coolix protocol. I tried a different remote too.

[crankyoldgit]

You can't compare the two signals that simply.

The first image looks like you're probing between the IR demodulator and the ESP. That is a demodulated signal. i.e. devoid of carrier frequency modulation and duty cycle information. i.e. It has been pre-processed somewhat into a more simpler digital form.

The second image looks like the output from transmission GPIO or transistor. i.e. To the IR LED. That signal is NOT demodulated at all. It contains the carrier frequency modulation and the duty cycle information. i.e. It is almost as raw/analogue as it gets. (excluding the wave length of the photons (940nm)).

In order to see that more clearly, you will need to use a time resolution (square on your oscilloscope) of around 50us, not 5ms. i.e. 100x than what you are currently viewing.

In short, the 5ms (per square) resolution is a bit low for the demodulated (incoming) signal, you probably want 1ms resolution. Some of the pulses will be ~400-500us. i.e. 0.4-0.5ms.
For the outgoing/transmission signal, it will be oscillating (PWM) once ever 26us, when "on". i.e. a Mark signal. i.e spikes of 13us duration. So use a resolution of ~50us.

The library expects a demodulated IR signal as input (no spikes every 10-20us) to decode, but produces a modulated signal when transmitting (spikes ever 10-20us when "on").

You can see that in your two images. The first dip (A Mark/on) in the first image lasts about 5ms/5000us. That corresponds with the first section of dips in the second image, except its pulsing on and off at 38kHz (13us on, 13us off) during that "dip"/Mark/On section. i.e. It's turning on & off ~192 times during that 5ms/5000us period. The rest of the signal in your second image is not clear enough due to not enough resolution.

If you feed the output (modulated) signal into an demodulator IC/device (like the one you're using on the capture side), and look at the result, it will be similar to your first image.

See also: https://learn.sparkfun.com/tutorials/ir-communication/all

[ItaiCuker]

I understand a bit more now about probing the signals, but I still am unable to transmit IR codes successfully... with or without decoding

[crankyoldgit]

Try some of the items in https://github.com/crankyoldgit/IRremoteESP8266/wiki/Troubleshooting-Guide#sending-an-ir-signal