A heating platform that is simpler to make and has higher power.

    This project's physical verification uses a modular construction, suitable for beginners with modest requirements.
    Based on the STM32F103C8T6 minimum system board, it controls the PTC heating plate power by adjusting the PWM duty cycle to control the SSR solid-state relay. A MAX6675 temperature sensor module with a K-type thermocouple is used for temperature measurement, and PID temperature control is implemented.
    The PID code has been adjusted and works stably on this system. For boards with different power ratings, PID tuning tips are as follows: increase the P value if the PWM change is too slow or the temperature rise is too slow; increase the D value if the temperature exceeds the set temperature by too much; increase the I value if the measured temperature fluctuates too much around the set temperature (the I value is almost unnecessary to adjust, as the effect is not significant).
    Ensure the accuracy of the measured temperature. Fix the K-type thermocouple to the PTC heating plate with thermally conductive adhesive, ensuring a bare-head K-type thermocouple is used.
    The PTC heating plate power and size can be freely replaced according to your needs. PID parameters need to be adjusted; the PID tuning uses USMART code from Zhengdian Atomic for easy debugging. A tutorial is attached. (There are discounts available for 21 yuan)
    SSR solid-state relays can control AC via DC. Theoretically, the power of the SSR solid-state relay selected can drive the same power of the PTC heating plate! (There are many discounts around 5 yuan, and you can buy it for 1 to 3 yuan)
    There is only one type of MAX6675 module on the market. For K-type thermocouples, be sure to choose the bare head type for more accurate temperature measurement. When using silicone rubber to attach K-type thermocouples, be careful to apply the glue layer by layer, otherwise the glue inside will not dry easily and will flow out when heated~~~ (There are cheaper options for 10.3 yuan) Rotary encoder module (4 yuan) Breadboard (2.31 yuan) Tactile buttons (1 yuan for 20 pieces)
Project cost: approximately 54.52 yuan (Since I needed to make a board for integration for the event, I took advantage of the free board making coupon from JLCPCB)
    The code uses the standard library, which uses relevant code from Jiangxie Technology and Zhengdian Atom.
Related videos are available on Bilibili: https://www.bilibili.com/video/BV1ej83edEfj/
Code link: High-power heating station: JLCPCB open source link: https://oshwhub.com/qq2568884002/simpler-and-higher-power-heating (gitee.com)
 
 
In addition, there is a very simple solution that does not require manual power-off temperature control: a temperature control switch. It has a purely mechanical structure, requires no code, and the temperature fluctuates within 30 degrees Celsius. If multiple temperature settings are needed, a switch can be added to switch between different temperature controls (just kidding).