change measurement method to resistor divider, slightly questionable and off by 10 degrees but that's probably good enough for baking bread

BluepillTrouba.ioc

@@ -11,10 +11,10 @@ ADC1.Rank-0\#ChannelRegularConversion=1
 ADC1.Rank-1\#ChannelRegularConversion=2
 ADC1.Rank-2\#ChannelRegularConversion=3
 ADC1.Rank-3\#ChannelRegularConversion=4
-ADC1.SamplingTime-0\#ChannelRegularConversion=ADC_SAMPLETIME_239CYCLES_5
+ADC1.SamplingTime-0\#ChannelRegularConversion=ADC_SAMPLETIME_41CYCLES_5
-ADC1.SamplingTime-1\#ChannelRegularConversion=ADC_SAMPLETIME_239CYCLES_5
+ADC1.SamplingTime-1\#ChannelRegularConversion=ADC_SAMPLETIME_41CYCLES_5
-ADC1.SamplingTime-2\#ChannelRegularConversion=ADC_SAMPLETIME_239CYCLES_5
+ADC1.SamplingTime-2\#ChannelRegularConversion=ADC_SAMPLETIME_41CYCLES_5
-ADC1.SamplingTime-3\#ChannelRegularConversion=ADC_SAMPLETIME_239CYCLES_5
+ADC1.SamplingTime-3\#ChannelRegularConversion=ADC_SAMPLETIME_41CYCLES_5
 ADC1.master=1
 Dma.ADC1.0.Direction=DMA_PERIPH_TO_MEMORY
 Dma.ADC1.0.Instance=DMA1_Channel1
@@ -105,6 +105,7 @@ NVIC.SavedSvcallIrqHandlerGenerated=true
 NVIC.SavedSystickIrqHandlerGenerated=true
 NVIC.SysTick_IRQn=true\:15\:0\:false\:false\:false\:true\:false\:true\:true
 NVIC.TIM1_UP_IRQn=true\:15\:0\:false\:false\:true\:false\:false\:true\:true
+NVIC.TIM4_IRQn=true\:5\:0\:false\:false\:true\:true\:true\:true\:true
 NVIC.TimeBase=TIM1_UP_IRQn
 NVIC.TimeBaseIP=TIM1
 NVIC.UsageFault_IRQn=true\:0\:0\:false\:false\:true\:false\:false\:false\:true
@@ -207,18 +208,19 @@ ProjectManager.TargetToolchain=Makefile
 ProjectManager.ToolChainLocation=
 ProjectManager.UnderRoot=false
 ProjectManager.functionlistsort=1-SystemClock_Config-RCC-false-HAL-false,2-MX_GPIO_Init-GPIO-false-HAL-true,3-MX_IWDG_Init-IWDG-false-HAL-true,4-MX_USART1_UART_Init-USART1-false-HAL-true,5-MX_ADC1_Init-ADC1-false-HAL-true,6-MX_SPI1_Init-SPI1-false-HAL-true,7-MX_DMA_Init-DMA-false-HAL-true,8-MX_TIM4_Init-TIM4-false-HAL-true,9-MX_TIM2_Init-TIM2-false-HAL-true
-RCC.ADCFreqValue=12000000
+RCC.ADCFreqValue=2250000
-RCC.ADCPresc=RCC_ADCPCLK2_DIV6
+RCC.ADCPresc=RCC_ADCPCLK2_DIV8
 RCC.AHBFreq_Value=72000000
 RCC.APB1CLKDivider=RCC_HCLK_DIV2
 RCC.APB1Freq_Value=36000000
 RCC.APB1TimFreq_Value=72000000
-RCC.APB2Freq_Value=72000000
+RCC.APB2CLKDivider=RCC_HCLK_DIV4
-RCC.APB2TimFreq_Value=72000000
+RCC.APB2Freq_Value=18000000
+RCC.APB2TimFreq_Value=36000000
 RCC.FCLKCortexFreq_Value=72000000
 RCC.FamilyName=M
 RCC.HCLKFreq_Value=72000000
-RCC.IPParameters=ADCFreqValue,ADCPresc,AHBFreq_Value,APB1CLKDivider,APB1Freq_Value,APB1TimFreq_Value,APB2Freq_Value,APB2TimFreq_Value,FCLKCortexFreq_Value,FamilyName,HCLKFreq_Value,MCOFreq_Value,PLLCLKFreq_Value,PLLMCOFreq_Value,PLLMUL,PLLSourceVirtual,RTCClockSelection,RTCFreq_Value,SYSCLKFreq_VALUE,SYSCLKSource,TimSysFreq_Value,USBFreq_Value,VCOOutput2Freq_Value
+RCC.IPParameters=ADCFreqValue,ADCPresc,AHBFreq_Value,APB1CLKDivider,APB1Freq_Value,APB1TimFreq_Value,APB2CLKDivider,APB2Freq_Value,APB2TimFreq_Value,FCLKCortexFreq_Value,FamilyName,HCLKFreq_Value,MCOFreq_Value,PLLCLKFreq_Value,PLLMCOFreq_Value,PLLMUL,PLLSourceVirtual,RTCClockSelection,RTCFreq_Value,SYSCLKFreq_VALUE,SYSCLKSource,TimSysFreq_Value,USBFreq_Value,VCOOutput2Freq_Value
 RCC.MCOFreq_Value=72000000
 RCC.PLLCLKFreq_Value=72000000
 RCC.PLLMCOFreq_Value=36000000
@@ -242,7 +244,7 @@ SH.S_TIM4_CH1.ConfNb=1
 SH.S_TIM4_CH2.0=TIM4_CH2,Encoder_Interface
 SH.S_TIM4_CH2.ConfNb=1
 SPI1.BaudRatePrescaler=SPI_BAUDRATEPRESCALER_8
-SPI1.CalculateBaudRate=9.0 MBits/s
+SPI1.CalculateBaudRate=2.25 MBits/s
 SPI1.Direction=SPI_DIRECTION_2LINES
 SPI1.IPParameters=VirtualType,Mode,Direction,BaudRatePrescaler,CalculateBaudRate
 SPI1.Mode=SPI_MODE_MASTER
@@ -251,7 +253,8 @@ TIM2.Channel-PWM\ Generation1\ CH1=TIM_CHANNEL_1
 TIM2.IPParameters=Channel-PWM Generation1 CH1,Prescaler
 TIM2.Prescaler=2
 TIM4.IC2Filter=15
-TIM4.IPParameters=IC2Filter
+TIM4.IPParameters=IC2Filter,Prescaler
+TIM4.Prescaler=0
 USART1.IPParameters=VirtualMode,Mode
 USART1.Mode=MODE_TX_RX
 USART1.VirtualMode=VM_ASYNC

Core/Inc/stm32f1xx_it.h

@@ -54,6 +54,7 @@ void UsageFault_Handler(void);
 void DebugMon_Handler(void);
 void DMA1_Channel1_IRQHandler(void);
 void TIM1_UP_IRQHandler(void);
+void TIM4_IRQHandler(void);
 /* USER CODE BEGIN EFP */
 
 /* USER CODE END EFP */

Core/Src/adc.c

@@ -59,7 +59,7 @@ void MX_ADC1_Init(void)
   */
   sConfig.Channel = ADC_CHANNEL_0;
   sConfig.Rank = ADC_REGULAR_RANK_1;
-  sConfig.SamplingTime = ADC_SAMPLETIME_239CYCLES_5;
+  sConfig.SamplingTime = ADC_SAMPLETIME_41CYCLES_5;
   if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
   {
     Error_Handler();

Core/Src/app.c

@@ -15,22 +15,27 @@
 #include "tim.h"
 #include "adc.h"
 #include "oled.h"
+#include "ufb/fb_text.h"
 
-// TODO averaging
+/* DMA dest */
 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
+const float V_REFINT = 1.23f;
+
+#define AVERAGEBUF_DEPTH 32
 
 static struct App {
   float oven_temp;
   float soc_temp;
   float v_sensor;
-  float v_current_reference;
+//  float v_current_reference;
-  float sensor_current;
+//  float sensor_current;
-  float r_sensor;
+//  float r_sensor;
   uint16_t wheel;
   bool push;
+  uint16_t adc_averagebuf[AVERAGEBUF_DEPTH * 4];
+  uint8_t averagebuf_ptr;
+  float adc_averages[4];
 } s_app = {};
 
 #define TSENSE_LOOKUP_LEN 101
@@ -38,25 +43,117 @@ static struct App {
 #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,
+        0.092678405931418f,
-        123.2419f, 125.16f, 127.0751f, 128.9874f, 130.8968f, 132.8033f, 134.7069f, 136.6077f, 138.5055f, 140.4005f, 142.2925f, 144.1817f,
+        0.0943174479327356f,
-        146.068f, 147.9514f, 149.8319f, 151.7096f, 153.5843f, 155.4562f, 157.3251f, 159.1912f, 161.0544f, 162.9147f, 164.7721f, 166.6267f,
+        0.095948157844312f,
-        168.4783f, 170.3271f, 172.1729f, 174.0159f, 175.856f, 177.6932f, 179.5275f, 181.359f, 183.1875f, 185.0132f, 186.8359f, 188.6558f,
+        0.0975706768542549f,
-        190.4728f, 192.2869f, 194.0981f, 195.9065f, 197.7119f, 199.5145f, 201.3141f, 203.1109f, 204.9048f, 206.6958f, 208.4839f, 210.2692f,
+        0.0991848957506647f,
-        212.0515f, 213.831f, 215.6075f, 217.3812f, 219.152f, 220.9199f, 222.6849f, 224.4471f, 226.2063f, 227.9627f, 229.7161f, 231.4667f,
+        0.100791037522732f,
-        233.2144f, 234.9592f, 236.7011f, 238.4402f, 240.1763f, 241.9096f, 243.6399f, 245.3674f, 247.092f, 248.8137f, 250.5325f, 252.2485f,
+        0.102388993070241f,
-        253.9615f, 255.6717f, 257.3789f, 259.0833f, 260.7848f, 262.4834f, 264.1791f, 265.872f, 267.5619f, 269.249f, 270.9331f, 272.6144f,
+        0.103978983136042f,
-        274.2928f, 275.9683f, 277.6409f, 279.3107f, 280.9775f
+        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 r_to_c(float r){
+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 >= r) {
+        if (cur >= val) {
             float prev = TSENSE_LOOKUP[i-1];
 
-            float ratio = (r - prev) / (cur - prev);
+            float ratio = (val - prev) / (cur - prev);
             return TSENSE_T_MIN + ((float) i + ratio) * TSENSE_T_STEP;
         }
     }
@@ -64,32 +161,45 @@ static float r_to_c(float r){
 }
 
 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 */
-    uint16_t refint = adc_values_snapshot[3];
+    float refint = s_app.adc_averages[3];
-    const float vrefint = 1.2f;
+    float scale = V_REFINT / refint;
-    float scale = vrefint / (float)refint;
 
-    const float avg_slope = 4.3f;
+    const float avg_slope = 4.3f * scale;
     const float v25 = 1.43f;
-    const float v_tsen = (float) adc_values_snapshot[2] * scale;
+    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 = (float)adc_values_snapshot[0] * scale;
+    s_app.v_sensor = s_app.adc_averages[0] * scale; // good for debug/tuning
-    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;
+    // using a voltage divider, so assuming the reference resistor is measured well,
-    s_app.r_sensor = s_app.v_sensor / s_app.sensor_current;
+    // we can just use the ratio and the exact voltage value is not important.
-    s_app.oven_temp = r_to_c(s_app.r_sensor);
+    s_app.oven_temp = val_to_c(s_app.adc_averages[0] / s_app.adc_averages[1]);
 }
 
 void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)
 {
     // notify
-    memcpy((void*) adc_values_snapshot, (const void*) adc_values, 8);
+    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);
 
@@ -119,17 +229,14 @@ void app_main_task(void *argument)
 
         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",
+//        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,
+//               (int) s_app.wheel, s_app.push,
-               adc_values[0], adc_values[1], adc_values[2], adc_values[3],
+//               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.oven_temp,
-                s_app.soc_temp,
+//                s_app.soc_temp,
-                s_app.v_sensor,
+//                s_app.v_sensor
-                s_app.v_current_reference,
+//        );
-                s_app.sensor_current,
-                s_app.r_sensor
-        );
 
         invert = !invert;
 
@@ -143,9 +250,15 @@ void app_main_task(void *argument)
                 fb_frame(s_app.wheel % FBW, 0, 15, 15, 1, 1);
             }
         }
+
+        char tmp[100];
+        sprintf(tmp, "%d°C", (int) s_app.oven_temp);
+
+        fb_text(0, 20, tmp, 0, 1);
+
         fb_blit();
 
-        vTaskDelay(250);
+        vTaskDelay(100);
 
         // beep
         htim2.Instance->ARR = 12000 + (int16_t)s_app.wheel * 100;

Core/Src/main.c

@@ -163,7 +163,7 @@ void SystemClock_Config(void)
   RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
   RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
   RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
-  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
+  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV4;
 
   if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
   {
@@ -171,7 +171,7 @@ void SystemClock_Config(void)
   }
   PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_RTC|RCC_PERIPHCLK_ADC;
   PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSE;
-  PeriphClkInit.AdcClockSelection = RCC_ADCPCLK2_DIV6;
+  PeriphClkInit.AdcClockSelection = RCC_ADCPCLK2_DIV8;
   if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
   {
     Error_Handler();

Core/Src/stm32f1xx_hal_timebase_tim.c

@@ -57,7 +57,7 @@ HAL_StatusTypeDef HAL_InitTick(uint32_t TickPriority)
   HAL_RCC_GetClockConfig(&clkconfig, &pFLatency);
 
   /* Compute TIM1 clock */
-  uwTimclock = HAL_RCC_GetPCLK2Freq();
+  uwTimclock = 2*HAL_RCC_GetPCLK2Freq();
   /* Compute the prescaler value to have TIM1 counter clock equal to 1MHz */
   uwPrescalerValue = (uint32_t) ((uwTimclock / 1000000U) - 1U);
 

Core/Src/stm32f1xx_it.c

@@ -57,6 +57,7 @@
 
 /* External variables --------------------------------------------------------*/
 extern DMA_HandleTypeDef hdma_adc1;
+extern TIM_HandleTypeDef htim4;
 extern TIM_HandleTypeDef htim1;
 
 /* USER CODE BEGIN EV */
@@ -190,6 +191,20 @@ void TIM1_UP_IRQHandler(void)
   /* USER CODE END TIM1_UP_IRQn 1 */
 }
 
+/**
+  * @brief This function handles TIM4 global interrupt.
+  */
+void TIM4_IRQHandler(void)
+{
+  /* USER CODE BEGIN TIM4_IRQn 0 */
+
+  /* USER CODE END TIM4_IRQn 0 */
+  HAL_TIM_IRQHandler(&htim4);
+  /* USER CODE BEGIN TIM4_IRQn 1 */
+
+  /* USER CODE END TIM4_IRQn 1 */
+}
+
 /* USER CODE BEGIN 1 */
 
 /* USER CODE END 1 */

Core/Src/tim.c

@@ -164,6 +164,9 @@ void HAL_TIM_Encoder_MspInit(TIM_HandleTypeDef* tim_encoderHandle)
     GPIO_InitStruct.Pull = GPIO_PULLUP;
     HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
 
+    /* TIM4 interrupt Init */
+    HAL_NVIC_SetPriority(TIM4_IRQn, 5, 0);
+    HAL_NVIC_EnableIRQ(TIM4_IRQn);
   /* USER CODE BEGIN TIM4_MspInit 1 */
 
   /* USER CODE END TIM4_MspInit 1 */
@@ -230,6 +233,8 @@ void HAL_TIM_Encoder_MspDeInit(TIM_HandleTypeDef* tim_encoderHandle)
     */
     HAL_GPIO_DeInit(GPIOB, KNOB_B_Pin|KNOB_A_Pin);
 
+    /* TIM4 interrupt Deinit */
+    HAL_NVIC_DisableIRQ(TIM4_IRQn);
   /* USER CODE BEGIN TIM4_MspDeInit 1 */
 
   /* USER CODE END TIM4_MspDeInit 1 */

Makefile

@@ -1,5 +1,5 @@
 ##########################################################################################################################
-# File automatically-generated by tool: [projectgenerator] version: [3.16.0] date: [Wed Feb 22 23:22:04 CET 2023] 
+# File automatically-generated by tool: [projectgenerator] version: [3.16.0] date: [Thu Feb 23 00:46:03 CET 2023]
 ##########################################################################################################################
 
 # ------------------------------------------------
@@ -174,8 +174,8 @@ LDSCRIPT = STM32F103CBTx_FLASH.ld
 # libraries
 LIBS = -lc -lm -lnosys
 LIBDIR =
-LDFLAGS = $(MCU)  -T$(LDSCRIPT) $(LIBDIR) $(LIBS) -Wl,-Map=$(BUILD_DIR)/$(TARGET).map,--cref -Wl,--gc-sections
+LDFLAGS = $(MCU) -specs=nano.specs -T$(LDSCRIPT) $(LIBDIR) $(LIBS) -Wl,-Map=$(BUILD_DIR)/$(TARGET).map,--cref -Wl,--gc-sections
-# -specs=nano.specs
+#
 
 # default action: build all
 all: $(BUILD_DIR)/$(TARGET).elf $(BUILD_DIR)/$(TARGET).hex $(BUILD_DIR)/$(TARGET).bin