toaster-oven-bluepill/Core/Src/app.c

/**
 * Main task
 */

#include <stdio.h>
#include <string.h>
#include "FreeRTOS.h"
#include "task.h"

#include "main.h"
#include "app.h"

#include "ufb/framebuffer.h"
#include "iwdg.h"
#include "tim.h"
#include "adc.h"
#include "oled.h"
#include "ufb/fb_text.h"

/* DMA dest */
static volatile uint16_t adc_values[4];

const float V_REFINT = 1.23f;

#define AVERAGEBUF_DEPTH 16
#define OVENTEMP_HISTORY_DEPTH 10

static struct App {
  bool heating;
  int16_t set_temp;
  int16_t wheel_normed;
  float oven_temp;
  float soc_temp;
  float v_sensor;
  uint16_t wheel;
  bool push;
  uint16_t adc_averagebuf[AVERAGEBUF_DEPTH * 4];
  uint8_t averagebuf_ptr;
  float adc_averages[4];
  float oventemp_history[OVENTEMP_HISTORY_DEPTH];
  uint8_t oventemp_history_ptr;
} s_app = {};

#define TSENSE_LOOKUP_LEN 101
#define TSENSE_T_STEP 5.0f
#define TSENSE_T_MIN 0.0f
#define TSENSE_T_MAX 500.0f
static const float TSENSE_LOOKUP[TSENSE_LOOKUP_LEN] = {
        0.092678405931418f,
        0.0943174479327356f,
        0.095948157844312f,
        0.0975706768542549f,
        0.0991848957506647f,
        0.100791037522732f,
        0.102388993070241f,
        0.103978983136042f,
        0.105560980458654f,
        0.107135039851509f,
        0.108701215616829f,
        0.110259642413441f,
        0.111810211533421f,
        0.113353137226489f,
        0.114888310929339f,
        0.11641594480226f,
        0.117936009906507f,
        0.119448557132363f,
        0.120953636903929f,
        0.122451377845456f,
        0.12394167187544f,
        0.125424725109556f,
        0.126900429638119f,
        0.128368989630084f,
        0.129830374697352f,
        0.131284632150064f,
        0.132731808872517f,
        0.134172027901771f,
        0.135605181883591f,
        0.13703146935069f,
        0.138450783142958f,
        0.139863319976468f,
        0.14126904821384f,
        0.142668011892657f,
        0.144060254660872f,
        0.145445894373796f,
        0.146824824486877f,
        0.14819723645253f,
        0.149563023938454f,
        0.150922376699229f,
        0.15227526202401f,
        0.153621720954182f,
        0.15496179417407f,
        0.156295594725426f,
        0.157623016940038f,
        0.158944245649448f,
        0.160259175412251f,
        0.16156798947087f,
        0.162870654195634f,
        0.164167207880495f,
        0.165457688491696f,
        0.166742204592451f,
        0.168020651444079f,
        0.169293207677971f,
        0.170559768793747f,
        0.171820511933356f,
        0.173075402684405f,
        0.174324476817747f,
        0.175567769803026f,
        0.176805386030345f,
        0.178037221732226f,
        0.179263449725904f,
        0.180483966491086f,
        0.181698943447122f,
        0.182908345518766f,
        0.184112206156428f,
        0.185310558533273f,
        0.186503503145257f,
        0.187690937227925f,
        0.188873028139146f,
        0.190049673368296f,
        0.191221038959601f,
        0.192387089280576f,
        0.193547855644572f,
        0.194703369109397f,
        0.195853726532112f,
        0.196998826174689f,
        0.19813883026229f,
        0.199273637315452f,
        0.200403408323351f,
        0.201528107189346f,
        0.20264776325594f,
        0.203762405629782f,
        0.204872127762998f,
        0.205976828960191f,
        0.207076666615101f,
        0.208171540293999f,
        0.209261606226334f,
        0.210346827933364f,
        0.211427232937629f,
        0.212502848543705f,
        0.213573765013592f,
        0.214639882704581f,
        0.215701354457324f,
        0.216758080892489f,
        0.217810213752734f,
        0.218857716249547f,
        0.219900614222686f,
        0.220938933310224f,
        0.221972760781578f,
        0.223001998051553f,
};

static float val_to_c(float val)
{
    // TODO use binary search.. lol
    for (int i = 1; i < TSENSE_LOOKUP_LEN; i++) {
        float cur = TSENSE_LOOKUP[i];
        if (cur >= val) {
            float prev = TSENSE_LOOKUP[i - 1];

            float ratio = (val - prev) / (cur - prev);
            return TSENSE_T_MIN + ((float) i + ratio) * TSENSE_T_STEP;
        }
    }
    return TSENSE_T_MAX;
}

void calculate_analog_values()
{
    uint32_t sums[4] = {};
    for (int i = 0; i < AVERAGEBUF_DEPTH * 4; i += 4) {
        sums[0] += s_app.adc_averagebuf[i];
        sums[1] += s_app.adc_averagebuf[i + 1];
        sums[2] += s_app.adc_averagebuf[i + 2];
        sums[3] += s_app.adc_averagebuf[i + 3];
    }
    s_app.adc_averages[0] = (float) sums[0] / AVERAGEBUF_DEPTH;
    s_app.adc_averages[1] = (float) sums[1] / AVERAGEBUF_DEPTH;
    s_app.adc_averages[2] = (float) sums[2] / AVERAGEBUF_DEPTH;
    s_app.adc_averages[3] = (float) sums[3] / AVERAGEBUF_DEPTH;

    /* r_pt100, r_ref, internal_temp, v_ref_int */
    float refint = s_app.adc_averages[3];
    float scale = V_REFINT / refint;

    const float avg_slope = 4.3f * scale;
    const float v25 = 1.43f;
    const float v_tsen = s_app.adc_averages[2] * scale;

    s_app.soc_temp = (v25 - v_tsen) / avg_slope + 25.f;
    s_app.v_sensor = s_app.adc_averages[0] * scale; // good for debug/tuning


    // using a voltage divider, so assuming the reference resistor is measured well,
    // we can just use the ratio and the exact voltage value is not important.
    float actual_temp = val_to_c(s_app.adc_averages[0] / s_app.adc_averages[1]);

    s_app.oventemp_history[s_app.oventemp_history_ptr] = actual_temp;
    s_app.oventemp_history_ptr = (s_app.oventemp_history_ptr + 1) % OVENTEMP_HISTORY_DEPTH;

    float sum = 0;
    for (int i = 0; i < OVENTEMP_HISTORY_DEPTH; i++) {
        sum += s_app.oventemp_history[i];
    }
    sum /= OVENTEMP_HISTORY_DEPTH;
    s_app.oven_temp = sum;
}

void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef *hadc)
{
    // notify
    memcpy((void *) &s_app.adc_averagebuf[s_app.averagebuf_ptr * 4], (const void *) adc_values, 8);
    s_app.averagebuf_ptr = (s_app.averagebuf_ptr + 1) % AVERAGEBUF_DEPTH;
}

static void hw_init()
{
    HAL_ADCEx_Calibration_Start(&hadc1);

    /* Start periodic reading of the ADC channels */
    HAL_ADC_Start_DMA(&hadc1, (uint32_t *) (void *) adc_values, 4);

    /* Enable the rotary encoder */
    HAL_TIM_Encoder_Start(&htim4, TIM_CHANNEL_ALL);

    /* Enable buzzer PWM */
    HAL_TIM_PWM_Start(&htim2, TIM_CHANNEL_1);

    /* Prepare the framebuffer and OLED interface */
    oled_init();
    fb_clear();
}

void app_main_task(void *argument)
{
    hw_init();

    /* Infinite loop */
    for (;;) {
        //HAL_GPIO_TogglePin(LED_GPIO_Port, LED_Pin);

//        printf("Knob %d (P=%d), ADC %.2f %.2f %.2f %.2f, oven %.2f°C, soc %.2f°C, divider %.3f V  \r\n",
//               (int) s_app.wheel, s_app.push,
//               s_app.adc_averages[0], s_app.adc_averages[1], s_app.adc_averages[2], s_app.adc_averages[3],
//
//                s_app.oven_temp,
//                s_app.soc_temp,
//                s_app.v_sensor
//        );

        calculate_analog_values();

        for (int i = 0; i < 50; i++) {
            uint16_t old_wheel = s_app.wheel;
            s_app.wheel = htim4.Instance->CNT;

            int16_t wheel_change = (int16_t)(s_app.wheel - old_wheel);

            if (wheel_change != 0) {
                s_app.wheel_normed += wheel_change;
                if (s_app.wheel_normed < 0) {
                    s_app.wheel_normed = 0;
                }
                if (s_app.wheel_normed > 500) {
                    s_app.wheel_normed = 500;
                }

                s_app.set_temp = (s_app.wheel_normed / 2) * 5;
            }

            s_app.push = 0 == HAL_GPIO_ReadPin(KNOB_PUSH_GPIO_Port, KNOB_PUSH_Pin);

            if (wheel_change != 0 || i == 0) {
                fb_clear();

                char tmp[100];

                sprintf(tmp, "Mereni: %d°C", (int) s_app.oven_temp);
                fb_text(10, 10, tmp, 0, 1);

                sprintf(tmp, "   Cil: %d°C", s_app.set_temp);
                fb_text(10, 25, tmp, 0, 1);

                if (s_app.heating) {
                    fb_frame(0, 0, FBW, FBH, 2, 1);
                }

                fb_blit();
            }

            vTaskDelay(10);
        }

        // regulation

        float set_f = (float) s_app.set_temp;

        if (!s_app.heating && s_app.oven_temp < set_f - 5.0f) { /* hysteresis */
            s_app.heating = true;
        }
        if (s_app.heating && s_app.oven_temp >= set_f) {
            s_app.heating = false;
        }

        HAL_GPIO_WritePin(HEATER_GPIO_Port, HEATER_Pin, s_app.heating);

        /*
        // beep
        htim2.Instance->ARR = 12000 + (int16_t)s_app.wheel * 100;
        htim2.Instance->CCR1 = htim2.Instance->ARR/2;
        vTaskDelay(50);
        htim2.Instance->ARR = 0;
         */

        // feed dogs
        HAL_IWDG_Refresh(&hiwdg);
    }
}