I'm using the stm32f429 discovery, I made a PWM control and tested it with a potentiometer and it worked as expected with 1mhz. Now I need to do the temperature control, I'm using a MAX31865 with PT100 and heating a resistance with the PWM output (this part is working very well) now for the PID it's not working right, I'm using:
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "MATH/MATH.h"//MAP
#include "MAX31865_lib.h"//MAX31865 PT100
#include "arm_math.h"//PID
/* USER CODE BEGIN 0 */
unsigned long Millis;
unsigned long TempoMillis;
unsigned long TempoMillis1;
uint16_t potenPWM;
uint16_t potenMAP;
extern bool MAX31865_Sensor_Error;
float PT100_Temperature = 0.0f;
uint16_t INT_PT100_Temperature;
//********************PWM CONTROL BY POTENTIOMETER USING ADC IT********************
// void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)
// {
// potenMAP = HAL_ADC_GetValue(&hadc1);
/*If continuousconversion mode is DISABLED uncomment below*/
//HAL_ADC_Start_IT (&hadc1);
// }
/* PID error */
float pid_error;
float PID_Temperatura_setpoint = 75.50;
float Tempetura_current;
float duty;
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_TIM1_Init();
MX_TIM2_Init();
MX_ADC1_Init();
MX_SPI1_Init();
/* USER CODE BEGIN 2 */
MAX31865_Init(3);
HAL_TIM_Base_Start(&htim1);
HAL_TIM_PWM_Start(&htim2, TIM_CHANNEL_1);
HAL_ADC_Start_IT (&hadc1);
//*************************************PID********************************************
/* ARM PID Instance, float_32 format */
arm_pid_instance_f32 PID;
/* Set PID parameters */
/* Set this for your needs */
PID.Kp = 100; /* Proporcional */
PID.Ki = 15; /* Integral */
PID.Kd = 0; /* Derivative */
/* Initialize PID system, float32_t format */
arm_pid_init_f32(&PID, 1);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
Millis = __HAL_TIM_GET_COUNTER(&htim1);
if(Millis - TempoMillis >= 500)
{
PT100_Temperature = MAX31865_Get_Temperature();
if (PT100_Temperature >= 0) {
PT100_Temperature = PT100_Temperature + 1.77;
} else {
PT100_Temperature = -PT100_Temperature + 1.77;
}
TempoMillis = Millis;
}
//****************PWM CONTROL BY POTENTIOMETER_Conversion_Or_IT********************
//HAL_ADC_Start(&hadc1);
// HAL_ADC_PollForConversion(&hadc1, 100);
//potenMAP = HAL_ADC_GetValue(&hadc1);
//potenPWM = MAP(potenMAP, 0, 4095, 0, 1000);
// __HAL_TIM_SET_COMPARE(&htim2,TIM_CHANNEL_1,potenPWM);
//****************************************PID****************************************
Tempetura_current = PT100_Temperature;
pid_error = (PID_Temperatura_setpoint - Tempetura_current);
duty = arm_pid_f32(&PID, pid_error);
if(duty<0){
duty=0;
}
if(duty >1000){
duty =1000;
}
__HAL_TIM_SET_COMPARE(&htim2,TIM_CHANNEL_1,duty);
}
/* USER CODE END 3 */
}
I made a video to show how the PID is behaving:
