I’m getting sick of fixing my TV remotes. Universal remotes are all over priced monsters. So instead I thought I’d wack together an IR blaster from the spare parts draw.

I thought it would be easy, infrared remotes use decades old technology. I wanted to use an ESP8266 I had laying around for its WiFi. Surely its a popular project with millions of guides and examples to work off?

Wasting nothing, I wanted to use the lil’ temperture sensors that my obsolete Corsair fan controller game with

Somehow it took me way too long to determine that they are 25k NTC Thermistors. Mainly because many fancy thermistor libraries for arduino out there support a huge list of types, with no indication of what is the most popular.

After this feat of detective work, I can basically hand the rest of this post to adafruit’s fantastic guide on how to use it surprisingly accurately with an actual algorithm to get a temperature in Celsius. For hardware, chuck in in series with a normal resistor to create a voltage divider, and use the analog pins to take measurements at the midpoint.

I’ve got a whole bunch of fancy Noctua PWM fans in my PC I want to control the speed of. How do I boss them around? The most authoritative source of how these fans communicate is from an Intel specification. Even better is a whitepaper by Noctua themselves that describes every detail you could ever want to know.

Okay so at least we aren’t going to be reverse engineering these fans. What exactly do they want on that PWM input pin?