When you need to match paint colors, one of the tools you’ll reach for is a deck of reference colors. Another might be a colorimeter. But what if you want both? [hallko1234] created just that by reverse-engineering and then patching a CR4501 colorimeter.
It starts with a problem: every time [hallko1234] needed to check a color, he had to take a reading, write it down, run to the office, match it with a table, and then walk all the way back. That sounds like too much effort. The natural solution, of course, is to automate the process.
So he did. The CR4501 will happily give you its entire firmware over the debug port, after which it was time for analysis in Ghidra. Some hiccups, brickings and accidental erasure of calibration data later, he finally had a working version. The end result is a simple screen that, after every time you measure, displays the closest RAL color code and how close it is.
On the off chance someone else has the same colorimeter, he even made an online tool to install it for you.
FYI most of the color meters, photometers, spectrometers, whatever, from China – are not full spectrum devices. They’re a couple of sensors of narrow band which it then extrapolates into a spectrum. You can’t use them for testing flashlights or LED bulbs or anything else. They’re totally bunk.
Just like the Chinese scales that see something get weighed for roughly 5g or 50g or 100g and cheat, displaying exactly that even value, guessing the user is attempting to verify the calibration.
China gonna China, figuring out every way it can to cheat.
Yeah well, cheap, cheap, and cheap. Pick any two.
For the low, low price of a $128.
Which is shockingly low for a color guessing machine that gets even close.
If I said you could buy a used car for $150 you wouldn’t say “yeah that’s not pocket money cheap. *rolls eyes.”
You would say “A car for $150? What’s wrong with it? That isn’t enough money for a functional car.”
A normal colorimeter for this purpose is like $2k-$10k.
<$150 makes me ask how it is cheating, and what the obvious downsides are.
It might be perfectly usable for some tasks though, which is great!