It won’t be feasible to change the MCPCB design again before production.
The inner tube issue is already solved, I think, but we’re waiting on test results to be sure.
Voodoo.
And probably more classroom theory than I’m using. When it oscillates, the oscillations are very regular, suggesting that it probably has a more formal design than what I’m using, or at least a much better signal-to-noise ratio on the sensor data. And probably more “I” with less “D”.
What I’m doing is a form of PID, but it’s less of a proper academic “Hogwarts/Brakebills” PID and more of a hedge witch “street” PID.
I have a H17F in a solid copper host with some serious thermal mass, and did some testing on its thermal response. This plot shows the H17F and an early version of Anduril from ~10 months ago. I found that DrJones’ method appeared to drop 1 PWM level every 0.5 seconds or so, until the FET was no longer active, then drop 1 PWM level every 2 seconds or so on the 7x7135 channel, until it was no longer overheating. It took about 8 minutes to stabilize, because the adjustment was very slow. Very smooth though, and it seemed okay in such a solid host. Bumps on its graph were where I accidentally moved the light while checking its surface temperature.
Meanwhile, Anduril stabilized in about a minute. These results are not directly comparable though, due to being in different hosts with different power levels. So at some point I should probably compare them in the same host to find out if the H17F can speed up when necessary.
On the FW3A, there was a spare pin so it actually has an “optic nerve” built in to be able to use the LED as a light sensor. But the way it’s designed probably wouldn’t work for temperature for a variety of reasons. Mostly, the reading is designed to auto-center on zero over time, so edges are visible but absolute levels are not.
The first prototype will likely soon become a dev host for optical sensor features. Those aren’t planned for release, but perhaps in a later version. Configuring a flashlight from a computer screen is a neat trick, but it’s mostly not very practical so I haven’t prioritized it.