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"

// TODO averaging
static volatile uint16_t adc_values[4];
static volatile uint16_t adc_values_snapshot[4];

const float r_current_sensor = 98.2f; // Ohm TODO measure

static struct App {
  float oven_temp;
  float soc_temp;
  float v_sensor;
  float v_current_reference;
  float sensor_current;
  float r_sensor;
  uint16_t wheel;
  bool push;
} 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] = {
        100.0f, 101.9527f, 103.9025f, 105.8495f, 107.7935f, 109.7347f, 111.6729f, 113.6083f, 115.5408f, 117.4704f, 119.3971f, 121.321f,
        123.2419f, 125.16f, 127.0751f, 128.9874f, 130.8968f, 132.8033f, 134.7069f, 136.6077f, 138.5055f, 140.4005f, 142.2925f, 144.1817f,
        146.068f, 147.9514f, 149.8319f, 151.7096f, 153.5843f, 155.4562f, 157.3251f, 159.1912f, 161.0544f, 162.9147f, 164.7721f, 166.6267f,
        168.4783f, 170.3271f, 172.1729f, 174.0159f, 175.856f, 177.6932f, 179.5275f, 181.359f, 183.1875f, 185.0132f, 186.8359f, 188.6558f,
        190.4728f, 192.2869f, 194.0981f, 195.9065f, 197.7119f, 199.5145f, 201.3141f, 203.1109f, 204.9048f, 206.6958f, 208.4839f, 210.2692f,
        212.0515f, 213.831f, 215.6075f, 217.3812f, 219.152f, 220.9199f, 222.6849f, 224.4471f, 226.2063f, 227.9627f, 229.7161f, 231.4667f,
        233.2144f, 234.9592f, 236.7011f, 238.4402f, 240.1763f, 241.9096f, 243.6399f, 245.3674f, 247.092f, 248.8137f, 250.5325f, 252.2485f,
        253.9615f, 255.6717f, 257.3789f, 259.0833f, 260.7848f, 262.4834f, 264.1791f, 265.872f, 267.5619f, 269.249f, 270.9331f, 272.6144f,
        274.2928f, 275.9683f, 277.6409f, 279.3107f, 280.9775f
};

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

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

void calculate_analog_values() {
    /* r_pt100, r_ref, internal_temp, v_ref_int */
    uint16_t refint = adc_values_snapshot[3];
    const float vrefint = 1.2f;
    float scale = vrefint / (float)refint;

    const float avg_slope = 4.3f;
    const float v25 = 1.43f;
    const float v_tsen = (float) adc_values_snapshot[2] * scale;

    s_app.soc_temp = (v25 - v_tsen) / avg_slope + 25.f;
    s_app.v_sensor = (float)adc_values_snapshot[0] * scale;
    s_app.v_current_reference = (float)(adc_values_snapshot[1] - adc_values_snapshot[0]) * scale;

    s_app.sensor_current = s_app.v_current_reference / r_current_sensor;
    s_app.r_sensor = s_app.v_sensor / s_app.sensor_current;
    s_app.oven_temp = r_to_c(s_app.r_sensor);
}

void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)
{
    // notify
    memcpy((void*) adc_values_snapshot, (const void*) adc_values, 8);
}

static void hw_init()
{
    /* 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 */
    bool invert = 0;
    for(;;)
    {
        HAL_GPIO_TogglePin(LED_GPIO_Port, LED_Pin);

        s_app.wheel = htim4.Instance->CNT;
        s_app.push = 0 == HAL_GPIO_ReadPin(KNOB_PUSH_GPIO_Port, KNOB_PUSH_Pin);

        calculate_analog_values();

        printf("Knob %d (P=%d), ADC %d %d %d %d, oven %.2f°C, soc %.2f°C, vPt %.3fV, v_iref %.3f, I %.6fA, rPt %.2f Ohm  \r\n",
               (int) s_app.wheel, s_app.push,
               adc_values[0], adc_values[1], adc_values[2], adc_values[3],

                s_app.oven_temp,
                s_app.soc_temp,
                s_app.v_sensor,
                s_app.v_current_reference,
                s_app.sensor_current,
                s_app.r_sensor
        );

        invert = !invert;

        fb_clear();
        if (s_app.push) {
            fb_rect(s_app.wheel % FBW, 0, 15, 15, 1);
        } else {
            if (invert) {
                fb_frame(s_app.wheel % FBW, 0, 15, 15, 2, 1);
            } else {
                fb_frame(s_app.wheel % FBW, 0, 15, 15, 1, 1);
            }
        }
        fb_blit();

        vTaskDelay(250);

        // 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);
    }
}