building an IR emitter and transmitter for my room

Firstly, thanks for reading my post! I am very excited about this project and had done a fair amount of research. I have zero experience in anything to do with Arduino but I do have basic knowledge and had build many custom computers to be fair. To begin my journey into Arduino, I would like to show you my plan based on the research I had done;

Unified IR remote controlled project for my room.
In short, What Im trying to achieve is;

  1. Use my keyboard to power on/off my AC unit and av receiver.
  2. Use one IR remote to power my ac unit and av receiver.

Based on my research, the hardware I need;

  1. Arduino nano ch340 (connected and USB powered by PC)
  2. This IR emitter and transmitter http://www.lelong.com.my/digital-38khz-infrared-ir-sensor-transmitter-kit-arduino-ubitronix-177577761-2018-05-Sale-P.htm
  3. USB cable - to power the controller

Im not really sure whether i would need extra resistors as some of the schematics ive seen had resistors at the IR led but some didn't which leads me to the question

  1. Is the hardware chosen sufficient? do i need to add resistors anywhere?
  2. Ive based my plans largely on this http://www.build-electronic-circuits.com/arduino-remote-control/
    I understand that resistors reduce current but can you explain more based on the site's schematics why he added a resistor on the ir led and not the ir receiver?
  3. What would your plan be if it was your project?

Thank you so much for taking the time to read my post and answering them!

There are a few things that are not clear.
You want to switch mains powered equipment on and off with an IR remote control unit ?
If that is the case, You'll need a relay unit as well. Probably double if you need to control the devices separately.

The IR sensor you have linked does not specify what device it contains. If you want only on/off, that might be OK but it may be good to have one (say TSOP4838) where there is an Arduino library which can be used to interpret the codes sent from the remote control unit.

You referred to a keyboard? is this a PC keyboard ?

If you have LEDs, there should always be a current limiting resistor. If you use ready built modules, these may be included.

Thank for your reply!

Yeap that's correct. I would only like to manipulate IR signals currently with my both an IR remote and a PC keyboard via my computer.

I do however have plans for relays but that's only for the second phase as i would really like my first attempt to work as learn more about arduino.

Thanks for the tip on IR sensors. Do you think this IR shield would work?
http://www.desensed.com/shield-module/129-arduino-ir-infrared-shield.html

Your link doesn't work for me (wrong country)

But, here is a quite a good description of Arduino with IR:
https://learn.adafruit.com/using-an-infrared-library/hardware-needed

How do you intend to integrate IR with your computer (PC) ?