feat(hepa-uv): add tachometer support to read hepa fan rpm.

hepa-uv/firmware/hepa_control_task/hepa_control_hardware.cpp

@@ -6,4 +6,8 @@ using namespace hepa_control_hardware;
 
 void HepaControlHardware::set_hepa_fan_speed(uint32_t duty_cycle) {
     set_hepa_fan_pwm(duty_cycle);
+}
+
+uint32_t HepaControlHardware::get_hepa_fan_rpm() {
+    return get_hepa_fan_rpm();
 }

hepa-uv/firmware/hepa_hardware.c

@@ -1,6 +1,67 @@
 #include "hepa-uv/firmware/hepa_hardware.h"
+#include "hepa-uv/firmware/utility_gpio.h"
+#include "common/firmware/errors.h"
 #include "timer_hardware.h"
 
+TIM_HandleTypeDef htim2;
+TIM_MasterConfigTypeDef sMasterConfig = {0};
+TIM_IC_InitTypeDef sConfigIC = {0};
+
+void tachometer_gpio_init(void) {
+    /* Peripheral clock enable */
+    __HAL_RCC_GPIOA_CLK_ENABLE();
+    __GPIOA_CLK_ENABLE();
+    /* HEPA_FG GPIO Configuration
+    PA5     ------> TIM2_CH1
+    */
+    GPIO_InitTypeDef GPIO_InitStruct = {0};
+    GPIO_InitStruct.Pin = HEPA_FG_MCU_PIN;
+    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
+    GPIO_InitStruct.Pull = GPIO_NOPULL;
+    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
+    GPIO_InitStruct.Alternate = GPIO_AF1_TIM2;
+    HAL_GPIO_Init(HEPA_FG_MCU_PORT, &GPIO_InitStruct);
+}
+
+static void TIM2_Tachometer_Init(void) {
+    htim2.Instance = TIM2;
+    htim2.State = HAL_TIM_STATE_RESET;
+    htim2.Init.Prescaler = 2;
+    htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
+    htim2.Init.Period = 4.294967295E9;
+    htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
+    htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
+    if (HAL_TIM_Base_Init(&htim2) != HAL_OK) {
+        Error_Handler();
+    }
+    /* Initialize Input Capture mode */
+    if (HAL_TIM_IC_Init(&htim2) != HAL_OK) {
+        Error_Handler();
+    }
+    sMasterConfig.MasterOutputTrigger = TIM_TRGO_ENABLE;
+    sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
+    if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) !=
+        HAL_OK) {
+        Error_Handler();
+    }
+    /* Initialize TIM2 input capture channel */
+    sConfigIC.ICPolarity = TIM_INPUTCHANNELPOLARITY_RISING;
+    sConfigIC.ICSelection = TIM_ICSELECTION_DIRECTTI;
+    sConfigIC.ICPrescaler = TIM_ICPSC_DIV4;
+    sConfigIC.ICFilter = 0;
+    if (HAL_TIM_IC_ConfigChannel(&htim2, &sConfigIC, TIM_CHANNEL_1) != HAL_OK) {
+        Error_Handler();
+    }
+    /* The update event of the enable timer is interrupted */
+    __HAL_TIM_ENABLE_IT(&htim2, TIM_IT_UPDATE);
+    /* Start the input capture measurement */
+    HAL_TIM_IC_Start_IT(&htim2, TIM_CHANNEL_1);
+
+    // /* TIM2 interrupt Init */
+    HAL_NVIC_SetPriority(TIM2_IRQn, 5, 0);
+    HAL_NVIC_EnableIRQ(TIM2_IRQn);
+}
+
 static uint32_t clamp(uint32_t val, uint32_t min, uint32_t max) {
     if (val < min) return min;
     if (val > max) return max;
@@ -9,5 +70,45 @@ static uint32_t clamp(uint32_t val, uint32_t min, uint32_t max) {
 
 void set_hepa_fan_pwm(uint32_t duty_cycle) {
     // calculate the pulse width from the duty cycle
-    htim3.Instance->CCR1 = clamp(duty_cycle, 0, 100) * htim3.Init.Period / 100;
+    uint32_t clamped_dc = clamp(duty_cycle, 0, 100) * htim3.Init.Period / 100;
+    htim3.Instance->CCR1 = clamped_dc;
+}
+
+uint32_t val1 = 0;
+uint32_t val2 = 0;
+uint32_t tach_period = 0;
+uint8_t captured_val1 = 0;
+
+uint32_t get_hepa_fan_rpm(void) {
+    if (tach_period == 0) return 0;
+    uint32_t rpm = ((uint32_t)HEPA_TACHOMETER_TIMER_FREQ * 60) \
+        / ((uint32_t)tach_period);
+    return rpm;
 }
+
+void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim) {
+    if (htim == &htim2) {
+        uint32_t count = __HAL_TIM_GET_COUNTER((TIM_HandleTypeDef*)htim);
+        if (captured_val1 == 0) {
+            val1 = count;
+            captured_val1 = 1;
+        } else {
+            val2 = count;
+        }
+
+        if (val2 > val1) {
+            tach_period = val2 - val1;
+            captured_val1 = 0;
+            __HAL_TIM_SET_COUNTER(htim, 0);
+        } else {
+            tach_period = 0;
+        }
+
+        __HAL_TIM_CLEAR_FLAG(htim, TIM_FLAG_UPDATE);
+    }
+}
+
+void initialize_tachometer() {
+    tachometer_gpio_init();
+    TIM2_Tachometer_Init();
+}

hepa-uv/firmware/main_rev1.cpp

@@ -25,6 +25,7 @@
 #include "hepa-uv/firmware/hepa_control_hardware.hpp"
 #include "hepa-uv/firmware/led_control_hardware.hpp"
 #include "hepa-uv/firmware/utility_gpio.h"
+#include "hepa-uv/firmware/hepa_hardware.h"
 #include "i2c/firmware/i2c_comms.hpp"
 #include "timer_hardware.h"
 
@@ -155,6 +156,7 @@ auto main() -> int {
     RCC_Peripheral_Clock_Select();
     utility_gpio_init();
     initialize_pwm_hardware();
+    initialize_tachometer();
     // set push button leds white
     led_hardware.set_button_led_power(HEPA_BUTTON, 0, 0, 0, 50);
     led_hardware.set_button_led_power(UV_BUTTON, 0, 0, 0, 50);

hepa-uv/firmware/stm32g4xx_it.c

@@ -43,6 +43,7 @@
 /* Private functions ---------------------------------------------------------*/
 
 /* External variables --------------------------------------------------------*/
+extern TIM_HandleTypeDef htim2;
 DMA_HandleTypeDef hdma_spi1_tx;
 DMA_HandleTypeDef hdma_spi1_rx;
 
@@ -135,6 +136,12 @@ void EXTI15_10_IRQHandler(void) {
     }
 }
 
+/**
+ * @brief This function handles TIM2 global interrupt.
+ */
+__attribute__((section(".ccmram")))
+void TIM2_IRQHandler(void) { HAL_TIM_IRQHandler(&htim2); }
+
 /**
  * @brief This function handles DMA1 channel2 global interrupt.
  */

hepa-uv/firmware/stm32g4xx_it.h

@@ -46,6 +46,7 @@ void FDCAN1_IT0_IRQHandler(void);
 void EXTI2_IRQHandler(void);
 void EXTI9_5_IRQHandler(void);
 void EXTI15_10_IRQHandler(void);
+void TIM2_IRQHandler(void);
 
 #ifdef __cplusplus
 }

hepa-uv/firmware/timer_hardware.c

@@ -31,6 +31,8 @@ uint32_t calc_prescaler(uint32_t timer_clk_freq, uint32_t counter_clk_freq) {
 void HAL_TIM_Base_MspInit(TIM_HandleTypeDef* htim) {
     if(htim->Instance == TIM1) {
         __HAL_RCC_TIM1_CLK_ENABLE();
+    } else if(htim->Instance == TIM2) {
+        __HAL_RCC_TIM2_CLK_ENABLE();
     } else if(htim->Instance == TIM3) {
         __HAL_RCC_TIM3_CLK_ENABLE();
     } else if(htim->Instance == TIM8) {

hepa-uv/firmware/timer_hardware.h

@@ -22,11 +22,13 @@ extern "C" {
 
 extern TIM_HandleTypeDef htim1;
 extern TIM_HandleTypeDef htim3;
+extern TIM_HandleTypeDef htim2;
 extern TIM_HandleTypeDef htim8;
 extern TIM_HandleTypeDef htim16;
 extern TIM_HandleTypeDef htim20;
 
 extern TIM_OC_InitTypeDef htim1_sConfigOC;
+extern TIM_OC_InitTypeDef htim2_sConfigOC;
 extern TIM_OC_InitTypeDef htim3_sConfigOC;
 extern TIM_OC_InitTypeDef htim8_sConfigOC;
 extern TIM_OC_InitTypeDef htim16_sConfigOC;

hepa-uv/firmware/utility_gpio.c

@@ -141,20 +141,20 @@ void uv_on_off_output_init() {
  */
 static void nvic_priority_enable_init() {
     /* EXTI interrupt init DOOR_OPEN_MCU : PC7*/
-    // PC7 -> GPIO_EXTI6 (EXTI9_5_IRQn)
+    // PC7 -> GPIO_EXTI7 (EXTI9_5_IRQn)
     HAL_NVIC_SetPriority(EXTI9_5_IRQn, 5, 0);
     HAL_NVIC_EnableIRQ(EXTI9_5_IRQn);
 
     /* EXTI interrupt init REED_SW_MCU : PC11*/
     /* EXTI interrupt init HEPA_NO_MCU : PB10*/
     // PC11 -> GPIO_EXTI11 (EXTI15_10_IRQn)
     // PB11 -> GPIO_EXTI11 (EXTI15_10_IRQn)
-    HAL_NVIC_SetPriority(EXTI15_10_IRQn, 5, 0);
+    HAL_NVIC_SetPriority(EXTI15_10_IRQn, 6, 0);
     HAL_NVIC_EnableIRQ(EXTI15_10_IRQn);
 
     /* EXTI interrupt init UV_NO_MCU : PC2*/
     // PC2 -> GPIO_EXTI2 (EXTI2_IRQn)
-    HAL_NVIC_SetPriority(EXTI2_IRQn, 5, 0);
+    HAL_NVIC_SetPriority(EXTI2_IRQn, 6, 0);
     HAL_NVIC_EnableIRQ(EXTI2_IRQn);
 }
 

include/hepa-uv/core/interfaces.hpp

@@ -32,5 +32,6 @@ class HepaControlInterface {
     virtual ~HepaControlInterface() = default;
 
     virtual auto set_hepa_fan_speed(uint32_t duty_cycle) -> void = 0;
+    virtual auto get_hepa_fan_rpm() -> uint32_t = 0;
 };
-}  // namespace hepa_control
+}  // namespace hepa_control

include/hepa-uv/firmware/hepa_control_hardware.hpp

@@ -14,6 +14,7 @@ class HepaControlHardware : public hepa_control::HepaControlInterface {
     ~HepaControlHardware() final = default;
 
     void set_hepa_fan_speed(uint32_t duty_cycle) final;
+    uint32_t get_hepa_fan_rpm() final;
 };
 
 }  // namespace hepa_control_hardware

include/hepa-uv/firmware/hepa_hardware.h

@@ -8,7 +8,11 @@
 extern "C" {
 #endif  // __cplusplus
 
+#define HEPA_TACHOMETER_TIMER_FREQ (20000U)
+
+void initialize_tachometer();
 void set_hepa_fan_pwm(uint32_t duty_cycle);
+uint32_t get_hepa_fan_rpm();
 
 #ifdef __cplusplus
 }  // extern "C"