This is my new controller.
The log:
The PID parameters used were tuned by using 2 gallons of water. I should’ve tuned with 5 gallon water, but I wanted to check the effectivity of PID parameters. The result seems to be OK. However, the temperature stability seems to be vulnerable to pump actions. The first turbulence was caused by adding malt, which was expected. The second turbulence at the beginning of MashOut was caused by adjustment of the flow rate of wort. The others were caused by turning on the pump.
What does it mean? Well, that means the temperature difference of the mash might be bigger than I have thought. Therefore, I will setup a multiple sensor for next brew.