Warmin up resistor with PID controller

[bartes19]

Posted on December 05, 2015 at 14:30

How you can warm up resistor. I have the task of warming up resistor to set the temperature with PID controller via usart. Please help !

microcontoller: STM32F411RE

[Andrei Chichak]

Posted on December 05, 2015 at 19:14

Is this a project for a class?

[bartes19]

Posted on December 06, 2015 at 14:02

No this is a project for me to pass the semester

I have to warming up resistor by transistor

[megahercas6]

Posted on December 06, 2015 at 17:14

I will be buying STM32F411, so i could help.

I don't know exact how it must be done, but i would place NTC thermistor connected to ADC to read temperature ( i have programs for this) and use PWM signal and n-ch mosfet to put some energy into load resistor. NTC must be thermally coupled with resistor you are warming up.

For uart, it is very easy, simply get FT232 uart converter, use STM32 examples on interrupt UART, so you send single number for temperature (like 255=100C, 0 = 10C)  or be smarter and use larger string for more resolution/control

Tricky part PID, it is very hard not to overshoot your target and get into oscillation, even i struggle to do this ( basically, you can't take heat, only give, that is problem, you will need adaptive PID or be smart how you implement it)