fix: 🐛 Fix TMS halt and temperature calculations. (#277)

* fix: 🐛 Fix TMS halt and temperature calculations.

Previously, TMS would appear to crash upon boot. This was caused by the `HAL_CAN_RxFifo0MsgPendingCallback` interrupt being triggered when the BMS sent CAN messages, even though the TMS does not care about them. TMS did not call `HAL_CAN_GetRxMessage()` in the interrupt to clear the interrupt flag, so the interrupt continued to fire, preventing the main code from running. This commit fixes the problem by handling the messages. Also fixes the temperature calculation which is now explicitly calculated from the sensor datasheet table and the physical hardware circuit.

* clean up interrupt callback

* Only toggle green on Update() and remove unused import

firmware/mcal/stm32f767/periph/can.h

@@ -15,12 +15,12 @@ namespace mcal::stm32f767::periph {
 
 class CanBase : public shared::periph::CanBase {
 public:
-    CanBase(CAN_HandleTypeDef* hcan) : hcan_(hcan){};
+    CanBase(CAN_HandleTypeDef* hcan) : hcan_(hcan) {};
 
     void Setup() {
-        HAL_CAN_ActivateNotification(hcan_, kCanRxActiveInterruptFifo0);
         ConfigFilters();
         HAL_CAN_Start(hcan_);
+        HAL_CAN_ActivateNotification(hcan_, kCanRxActiveInterruptFifo0);
     }
 
     void Send(const shared::can::RawCanMsg& can_tx_msg) override {

firmware/projects/EV5/TMS/inc/app.h

@@ -25,22 +25,23 @@
 class TempSensor {
 public:
     TempSensor(shared::periph::ADCInput& adc,
-               shared::util::Mapper<float>& adc_to_temp)
-        : adc_(adc), adc_to_temp_(adc_to_temp), rolling_temperature_() {}
+               const shared::util::Mapper<float>& volt_to_temp)
+        : adc_(adc), volt_to_temp_(volt_to_temp), rolling_temperature_() {}
 
 private:
     shared::periph::ADCInput& adc_;
 
     /// @brief Mapping from raw ADC value to temperature [degC]
-    shared::util::Mapper<float>& adc_to_temp_;
+    const shared::util::Mapper<float>& volt_to_temp_;
 
     static constexpr int moving_average_length_ = 20;
     shared::util::MovingAverage<float, moving_average_length_>
         rolling_temperature_;
 
     float Read() {
         uint32_t adc_value = adc_.Read();
-        float temperature = adc_to_temp_.Evaluate(float(adc_value));
+        float volt = static_cast<float>(adc_value) * 3.3f / 4095.0f;
+        float temperature = volt_to_temp_.Evaluate(volt);
         return temperature;
     }
 

firmware/projects/EV5/TMS/main.cc

@@ -13,7 +13,9 @@
 #include "shared/periph/gpio.h"
 #include "shared/periph/pwm.h"
 #include "shared/util/algorithms/arrays.h"
+#include "shared/util/mappers/linear_map.h"
 #include "shared/util/mappers/lookup_table.h"
+#include "shared/util/mappers/mapper.h"
 #include "veh_can_messages.h"
 #include "veh_msg_registry.h"
 
@@ -27,54 +29,76 @@ extern "C" {
 void UpdateTask(void* argument);
 }
 
-const float temp_lut_data[][2] = {
+namespace tempsensor {
+
+/// This table is directly copied from Table 4 of the temperature sensor
+/// datasheet. `datasheets/energus/Datasheet_with_VTC6_rev_A(2021-10-26).pdf`
+const float ts_table[][2] = {
     // clang-format off
-    {2475, 120},
-	{2480, 115},
-	{2485, 110},
-	{2491, 105},
-	{2496, 100},
-	{2501,  95},
-	{2512,  90},
-	{2517,  85},
-	{2528,  80},
-	{2543,  75},
-	{2554,  70},
-	{2570,  65},
-	{2586,  60},
-	{2607,  55},
-	{2628,  50},
-	{2649,  45},
-	{2675,  40},
-	{2707,  35},
-	{2739,  30},
-	{2771,  25},
-	{2802,  20},
-	{2839,  15},
-	{2871,  10},
-	{2903,   5},
-	{2934,   0},
-	{2966,  -5},
-	{2987, -10},
-	{3014, -15},
-	{3029, -20},
-	{3045, -25},
-	{3056, -30},
-	{3066, -35},
-    {3077, -40},
+    {1.30f, 120.0f},
+    {1.31f, 115.0f},
+    {1.32f, 110.0f},
+    {1.33f, 105.0f},
+    {1.34f, 100.0f},
+    {1.35f,  95.0f},
+    {1.37f,  90.0f},
+    {1.38f,  85.0f},
+    {1.40f,  80.0f},
+    {1.43f,  75.0f},
+    {1.45f,  70.0f},
+    {1.48f,  65.0f},
+    {1.51f,  60.0f},
+    {1.55f,  55.0f},
+    {1.59f,  50.0f},
+    {1.63f,  45.0f},
+    {1.68f,  40.0f},
+    {1.74f,  35.0f},
+    {1.80f,  30.0f},
+    {1.86f,  25.0f},
+    {1.92f,  20.0f},
+    {1.99f,  15.0f},
+    {2.05f,  10.0f},
+    {2.11f,   5.0f},
+    {2.17f,   0.0f},
+    {2.23f,  -5.0f},
+    {2.27f, -10.0f},
+    {2.32f, -15.0f},
+    {2.35f, -20.0f},
+    {2.38f, -25.0f},
+    {2.40f, -30.0f},
+    {2.42f, -35.0f},
+    {2.44f, -40.0f}
     // clang-format on
 };
+constexpr int lut_length = (sizeof(ts_table)) / (sizeof(ts_table[0]));
+const shared::util::LookupTable<lut_length> volt_ts_to_degC{ts_table};
+
+/// Calculate the voltage at the temperature sensor from the voltage at the STM.
+/// They are not equal because there is a non-unity gain buffer between them.
+/// V_STM = 1.44 + 0.836 * V_TS / 2
+/// So the inverse is
+/// V_TS = 2 * (V_STM - 1.44) / 0.836 = 2/0.836 * V_STM - 2*1.44/0.836
+const shared::util::LinearMap<float> volt_stm_to_volt_ts{
+    2.0f / 0.836f,
+    -2.0f * 1.44f / 0.836f,
+};
+
+/// Compose the two maps to get the final map from the STM voltage to the
+/// temperature in degrees C.
+const shared::util::CompositeMap<float> volt_stm_to_degC{
+    volt_ts_to_degC,      // outer (second) function
+    volt_stm_to_volt_ts,  // inner (first) function
+};
+
+}  // namespace tempsensor
 
+/// Spin the fan faster when the acculumator is hotter.
 const float fan_lut_data[][2] = {
     {-1, 0},
     {0, 30},
     {50, 100},
 };
 
-constexpr int temp_lut_length =
-    (sizeof(temp_lut_data)) / (sizeof(temp_lut_data[0]));
-shared::util::LookupTable<temp_lut_length> temp_adc_lut{temp_lut_data};
-
 constexpr int fan_lut_length =
     (sizeof(fan_lut_data) / (sizeof(fan_lut_data[0])));
 shared::util::LookupTable<fan_lut_length> fan_temp_lut{fan_lut_data};
@@ -99,12 +123,12 @@ DebugIndicator debug_green{bindings::debug_led_green};
 DebugIndicator debug_red{bindings::debug_led_red};
 
 TempSensor temp_sensors[] = {
-    TempSensor{bindings::temp_sensor_adc_1, temp_adc_lut},
-    TempSensor{bindings::temp_sensor_adc_2, temp_adc_lut},
-    TempSensor{bindings::temp_sensor_adc_3, temp_adc_lut},
-    TempSensor{bindings::temp_sensor_adc_4, temp_adc_lut},
-    TempSensor{bindings::temp_sensor_adc_5, temp_adc_lut},
-    TempSensor{bindings::temp_sensor_adc_6, temp_adc_lut},
+    TempSensor{bindings::temp_sensor_adc_1, tempsensor::volt_stm_to_degC},
+    TempSensor{bindings::temp_sensor_adc_2, tempsensor::volt_stm_to_degC},
+    TempSensor{bindings::temp_sensor_adc_3, tempsensor::volt_stm_to_degC},
+    TempSensor{bindings::temp_sensor_adc_4, tempsensor::volt_stm_to_degC},
+    TempSensor{bindings::temp_sensor_adc_5, tempsensor::volt_stm_to_degC},
+    TempSensor{bindings::temp_sensor_adc_6, tempsensor::volt_stm_to_degC},
 };
 
 const int kSensorCount = 6;
@@ -122,7 +146,6 @@ void Update() {
     static uint8_t high_thermistor_idx;
 
     debug_green.Toggle();
-    debug_red.Toggle();
 
     veh_can_bus.Update();
     ts_manager.Update();

firmware/projects/EV5/TMS/platforms/stm32f767/bindings.cc

@@ -1,6 +1,8 @@
 /// @author Blake Freer
 /// @date 2023-12-25
 
+#include <stdio.h>
+
 #include <string>
 
 // cubemx files
@@ -59,17 +61,28 @@ shared::periph::ADCInput& temp_sensor_adc_6 = mcal::temp_sensor_adc_6;
 shared::periph::PWMOutput& fan_controller_pwm = mcal::fan_controller_pwm;
 shared::periph::DigitalOutput& debug_led_green = mcal::debug_led_green;
 shared::periph::DigitalOutput& debug_led_red = mcal::debug_led_red;
-//  shared::periph::DigitalOutput& debug_led_red = mcal::debug_led_nucleo;
+// shared::periph::DigitalOutput& debug_led_red = mcal::debug_led_nucleo;
 
 shared::periph::CanBase& veh_can_base = mcal::veh_can_base;
 
 void Initialize() {
-    SystemClock_Config();
     HAL_Init();
+    SystemClock_Config();
     MX_ADC1_Init();
     MX_TIM4_Init();
     MX_GPIO_Init();
     MX_CAN2_Init();
+
+    mcal::veh_can_base.Setup();
 }
 
 }  // namespace bindings
+
+void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef* hcan) {
+    CAN_RxHeaderTypeDef RxHeader;
+    uint8_t RxData[8];
+
+    // TMS doesn't care about any Rx messages but we need to call this to
+    // clear the interrupt flag.
+    HAL_CAN_GetRxMessage(hcan, CAN_RX_FIFO0, &RxHeader, RxData);
+}

firmware/shared/util/mappers/mapper.h

@@ -34,7 +34,8 @@ class CompositeMap : public Mapper<Tf, U> {
      * @param g Inner function.
      * @note Evaulates `f(g(x))`, so `g` is applied before `f`.
      */
-    CompositeMap(Mapper<Tf, Tg>& f, Mapper<Tg, U>& g) : f_(f), g_(g) {}
+    CompositeMap(const Mapper<Tf, Tg>& f, const Mapper<Tg, U>& g)
+        : f_(f), g_(g) {}
 
     /**
      * @brief Evaluates `f(g(x))`.