After tweaking some control loop parameters and adding a hard-limit for the temperature (heater cut-off + resetting the error term, effectively restarting the loop), the massive temperature overshoots are a thing of the past.
I declare this a success.
“Some changes (video will come later):”
- Improved button response
- Display meaningful error message if the wand is not connected (FAN)
- Added persistent temperature set-point storage
- Tweaked the control loop some more :-)
- Display set-point once temperature is within +- 4°C (removes annoying noise on display)
I also had to fix one of the safety-earth wires. To be fair, it probably fatigued due to me dismantling the device many many times.