HPACS
Hot Plate Automatic Control System Videos: https://youtu.be/TlVIJFjHHOQ and https://youtu.be/JZ1UPQ5lsyg
For a bit more details look here: https://www.instructables.com/Hot-Plate-Automatic-Control-System-HPACS/
If you like then please
Purpose
This project aims at providing a simple intuitive way of understanding how to do Automatic PID tuning using a heater. What I have made is based on the Åström–Hägglund method for deriving parameters using bang-bang control to reveal system characteristics and subsequenctly chose parameters based on this knowledge. There is nothing secret to it and info can be found here: https://en.wikipedia.org/wiki/PID_controller#Loop_tuning And for chosing parameters you can read a bit here: https://en.wikipedia.org/wiki/Ziegler%E2%80%93Nichols_method
To make it nice a Nextion 3.2" HMI interface is added for user input and displaying different variables real-time. BUT I also made a Serial terminal version of the library which makes the project way cheaper !
The real background story is that partly I promised my dad to make a temperature control for melting bees wax, partly I wanted to refresh my basic control theory and finally I wanted to look into auto tuning of PID controllers. On the side I also managed to use it for Sous Vide making nice steaks and Bearnaise sauce as part of the testing !
Arduino based
The code is implemented on an Arduino Mega and uses two of the 16-bit timers for "PWM" and control loop. Furthermore, a Nextion 3.2" basic HMI panel is used on the HMI version of the code. I am not a software engineer so my coding may not be optimal or directly intuitive to others...
Dependencies
I use a couple of libraries in the code: "DallasTemperature", "EEPROMex", "ITEADLIB_Arduino_Nextion-master" and the more commonly known "OneWire".
Hardware/BOM
I use:
- A cheap WASCO Hot Plate
- A cheap SS-relay
- A Dallas onewire temperature sensor
- An Arduino Mega
- (Optional) A Nextion 3.2" HMI interface/display
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Find more of my work here:
https://youtube.com/user/wan46696
https://www.instructables.com/member/nicengineering/
License note: However, I have found the buttons for the HMI here: https://www.uihere.com/free-graphics/off-and-on-button-set-ai-eps-file-131170 Where it says "For Personal Use" under licensing - I.e. no commercialization of HPACS unless you change those buttons ;) Also the disk icon and the hot surface warning I found somewhere at some point - but I can't seem to find them again...