Although this device works very well it does not come with any IR firmware preloaded. That's not a bad thing, just letting others know.

The placement of the emitter and the sensor are easy, just follow the instructions. I recommend that you use a "fine tip" soldering iron.

The mounting holes are a nice touch and useful to me (somewhat). But I would have preferred that they were permanent and at the other end of the board.

Be patient with the firmware you choose to load onto it. The source I used has various adjustments that needed tweaking to get my remote to be received reliably. Once you've got that this device becomes convenient for decoding remotes and creating a program that transmits commands.

I've been using this for automating my stereo system and tv with home assistant and ESP-home, using the sparkfunBlynk template. Its uptime is good and is powered via my tv's usb port (not all tv usb ports work similar).You will have to do some work in figuring out the multitudes of ways engineers encode their data, it won't always be easy, but many use NEC, and you'll always have raw data to record, which this device allows. The ADC pin can also be used as a raw button pin via ESPhome.

You can salvage better IR leds from old tv remotes, or buy 5mm clear leds to fit your needs. I just shoved this in a too small hammond box and covered the whole thing in LEDs. With the amount of modding I've attemped on this bad boy I have damaged the thin traces to the IR output but I just have a bigger resistor from 3V3.

My only con is that ESPhome gets higher in bytes every patch, so wireless updating with many ir codes will have you fighting to keep save every bit, but if you program by header it will program no problem. I guess you could store a database of helper entities in home assistant, and the only code on the device for outputting the proper data, but I haven't gotten around to it, and so far haven't hit the true limit.

works great and proves what can be done

I was able to solder the diodes easily and put a 6 pin header into place to allow me to program the ESP8266 from the Arduino IDE on my Mac. First I tried an old Sparkfun FTDI basic breakout but couldn't get the driver to work so I used a CP2102 USB to TTL adapter that used a different driver. The only annoyance was that it didn't have the DTR pin, so I had to press the buttons on the IR Blaster board each time I wanted to send a program.

First I ran the receiver program so I could point my remote control at the receiver diode and then get the codes for each button on the remote as I pushed it. Then I pasted the codes into the web server sketch and tweaked it to allow me to communicate with the server via WiFi and then have the IR Blaster send these codes to the TV and cable box. I rewrote portions of the code to make this all work in the manner I preferred.

One initial roadblock is that the simple NEC Codes didn't seem to work on my TV or cable box, and I later discovered that my cable box didn't use the NEC protocol anyway, but rather something called GICable. Thus I ended up using the longer raw codes as described in the Sparkfun Hookup Guide and had to rewrite some portions of the Arduino sketch as a result. Maybe I could look at the documentation for the IR Blaster Arduino library a little more to see if I could send simpler codes, but the example code only showed NEC format and raw format.

Once everything was working, I wrote a simple app for my iPhone that allowed me to have logos for the various cable stations that I could push and send the corresponding request to the web server (which would then send the IR raw code via the WiFi blaster) as well as pretty buttons for the volume and channel controls and the on/off buttons for the TV and cable box. Now I only have to use one control (the iPhone) to control both devices.

Of course for a few more $$ I could have bought a fully-assembled and enclosed IR blaster from any number of suppliers, but I would have been tied to their own control software. All told it took me about a day or two of coding and experimenting to make everything work the way I wanted it to.