Added altimeter .hpp and .cpp files

Altimeter/Inc/altimeter.hpp

@@ -0,0 +1,166 @@
+#ifndef INC_ALTIMETER_HPP_
+#define INC_ALTIMETER_HPP_
+
+#include "stm32l5xx_hal.h"
+#include "cmsis_os.h"
+#include <cstdint>
+#include <cmath>
+
+
+#define RESET 0x1E
+
+/*PROM Addresses */
+#define PROM_READ_ADDRESS_0 0xA0
+#define PROM_READ_ADDRESS_1 0xA2
+#define PROM_READ_ADDRESS_2 0xA4
+#define PROM_READ_ADDRESS_3 0xA6
+#define PROM_READ_ADDRESS_4 0xA8
+#define PROM_READ_ADDRESS_5 0xAA
+#define PROM_READ_ADDRESS_6 0xAC
+#define PROM_READ_ADDRESS_7 0xAE
+
+
+/*digital pressure/temperature commands at different sampling rates*/
+#define CONVERT_D1_OSR_256 0x40
+#define CONVERT_D1_OSR_512 0x42
+#define CONVERT_D1_OSR_1024 0x44
+#define CONVERT_D1_OSR_2048 0x46
+#define CONVERT_D1_OSR_4096 0x48
+#define CONVERT_D2_OSR_256 0x50
+#define CONVERT_D2_OSR_512 0x52
+#define CONVERT_D2_OSR_1024 0x54
+#define CONVERT_D2_OSR_2048 0x56
+#define CONVERT_D2_OSR_4096 0x58
+
+#define ADC_READ 0x0
+
+#define TIMEOUT 1 << 31
+
+typedef struct cal_coeffs{
+ uint16_t sens;
+ uint16_t off;
+ uint16_t tcs;
+ uint16_t tco;
+ uint16_t t_ref;
+ uint16_t temp_sens;
+}cal_coeffs;
+
+
+
+/* To get temperature/pressure/altitude values, call (step 1) AltDevice, then (step 2) AltInit once.
+ * Then before getting (step 4) pressure/temp/altitude, (step 3) calculateTempPres should be called beforehand.
+ * */
+
+class AltDevice{
+public:
+ /**
+ * Constructor for the AltDevice class
+ *
+ * @param ps_port -> protocol select port
+ * @param ps_pin -> protocol select pin
+ *
+ * @return none
+ */
+ AltDevice(GPIO_TypeDef *ps_port, uint16_t ps_pin);
+
+ /**
+ * This function sends the reset command, populates the cal_coeffs
+ * struct members with the calibration coefficients in the sensor PROM,
+ * and gets the current elevation above sea level.
+ *
+ * @param ps_port -> protocol select port
+ * @param ps_pin -> protocol select pin
+ * @param spi_handle -> hspix handle
+ *
+ * @return none
+ */
+ void altInit(SPI_HandleTypeDef *spi_handle, GPIO_TypeDef *cs_port, uint16_t cs_pin);
+
+ /**
+ * Calculates datasheet variable values needed for temperature and pressure,
+ * and calculates temperature and pressure. It
+ *
+ * @param ps_port -> protocol select port
+ * @param ps_pin -> protocol select pin
+ * @param spi_handle -> hspix handle
+ *
+ * @return none
+ */
+ void calculateTempPres(SPI_HandleTypeDef *spi_handle, GPIO_TypeDef *cs_port, uint16_t cs_pin);
+
+
+ /**
+ * @return the current pressure value
+ */
+ float getPressure();
+
+ /**
+ * @return the current temperature value
+ */
+ float getTemperature();
+
+ /**
+ * @return the current altitude above sea level.
+ */
+ float getAltAboveSeaLvl();
+
+ /**
+ * @return the current altitude above zero point.
+ */
+ float getAltitude();
+
+
+private:
+ cal_coeffs coeffs_;
+ float base_elev_;
+ float height_;
+ float temp_;
+ float pres_;
+
+ /**
+ * Sends the reset command to the barometer.
+ *
+ * @param ps_port -> protocol select port
+ * @param ps_pin -> protocol select pin
+ * @param spi_handle -> hspix handle
+ *
+ * @return none
+ */
+ void reset(SPI_HandleTypeDef *spi_handle, GPIO_TypeDef *cs_port, uint16_t cs_pin);
+
+ /**
+ * Populates the struct with calibration coefficients.
+ *
+ * @param ps_port -> protocol select port
+ * @param ps_pin -> protocol select pin
+ * @param spi_handle -> hspix handle
+ *
+ * @return none
+ */
+ void getConvCoeffs(SPI_HandleTypeDef *spi_handle, GPIO_TypeDef *cs_port, uint16_t cs_pin);
+
+ /**
+ * Reads user-specified calibration coefficient from the PROM
+ *
+ * @param ps_port -> protocol select port
+ * @param ps_pin -> protocol select pin
+ * @param spi_handle -> hspix handle
+ *
+ * @return calibration data
+ */
+ uint16_t promRead(SPI_HandleTypeDef *spi_handle, GPIO_TypeDef *cs_port, uint16_t cs_pin, uint8_t address);
+
+ /**
+ * Reads uncompenssated temperature/pressure value from altimeter.
+ *
+ * @param ps_port -> protocol select port
+ * @param ps_pin -> protocol select pin
+ * @param spi_handle -> hspix handle
+ *
+ * @return uncompensated pressure/temperature value
+ */
+ uint32_t uncompensatedPressureTemperature(SPI_HandleTypeDef *spi_handle, GPIO_TypeDef *cs_port, uint16_t cs_pin, uint8_t conversion_command);
+};
+
+
+#endif /* INC_ALTIMETER_HPP_ */

Altimeter/Src/altimeter.cpp

@@ -0,0 +1,166 @@
+#include <altimeter.hpp>
+
+
+AltDevice::AltDevice(GPIO_TypeDef *ps_port, uint16_t ps_pin){
+ HAL_GPIO_WritePin(ps_port, ps_pin, GPIO_PIN_RESET);
+}
+
+void AltDevice::altInit(SPI_HandleTypeDef *spi_handle, GPIO_TypeDef *cs_port, uint16_t cs_pin){
+ reset(spi_handle, cs_port, cs_pin);
+ getConvCoeffs(spi_handle, cs_port, cs_pin);
+
+ /*Get the average of 100 readings*/
+
+ float reading_sum = 0.0f;
+ for(int i = 0; i < 100; i++){
+ calculateTempPres(spi_handle, cs_port, cs_pin);
+ reading_sum += getAltAboveSeaLvl();
+ }
+
+ base_elev_ = reading_sum / 100.0f;
+}
+
+void AltDevice::reset(SPI_HandleTypeDef *spi_handle, GPIO_TypeDef *cs_port, uint16_t cs_pin){
+
+ HAL_GPIO_WritePin(cs_port, cs_pin, GPIO_PIN_SET);
+ HAL_GPIO_WritePin(cs_port, cs_pin, GPIO_PIN_RESET);
+
+ uint8_t send_reset[3] = {RESET, 0xFF, 0xFF};
+ uint8_t receive_data[3];
+
+ HAL_SPI_TransmitReceive(spi_handle, send_reset, receive_data, 3, TIMEOUT);
+ osDelay(3);
+
+ HAL_GPIO_WritePin(cs_port, cs_pin, GPIO_PIN_SET);
+}
+
+void AltDevice::getConvCoeffs(SPI_HandleTypeDef *spi_handle, GPIO_TypeDef *cs_port, uint16_t cs_pin){
+ coeffs_.sens = promRead(spi_handle, cs_port, cs_pin, PROM_READ_ADDRESS_1);
+ coeffs_.off = promRead(spi_handle, cs_port, cs_pin, PROM_READ_ADDRESS_2);
+ coeffs_.tcs = promRead(spi_handle, cs_port, cs_pin, PROM_READ_ADDRESS_3);
+ coeffs_.tco = promRead(spi_handle, cs_port, cs_pin, PROM_READ_ADDRESS_4);
+ coeffs_.t_ref = promRead(spi_handle, cs_port, cs_pin, PROM_READ_ADDRESS_5);
+ coeffs_.temp_sens = promRead(spi_handle, cs_port, cs_pin, PROM_READ_ADDRESS_6);
+}
+
+
+uint16_t AltDevice::promRead(SPI_HandleTypeDef *spi_handle, GPIO_TypeDef *cs_port, uint16_t cs_pin, uint8_t address){
+ HAL_GPIO_WritePin(cs_port, cs_pin, GPIO_PIN_SET);
+ HAL_GPIO_WritePin(cs_port, cs_pin, GPIO_PIN_RESET);
+
+ uint8_t send_read_command[3] = {address, 0xFF, 0xFF};
+ uint8_t coefficient_val[3];
+
+ HAL_SPI_TransmitReceive(spi_handle, send_read_command, coefficient_val, 3, TIMEOUT);
+
+ HAL_GPIO_WritePin(cs_port, cs_pin, GPIO_PIN_SET);
+
+ //Grab conversion coefficients.
+ uint16_t conversion_coefficient = (coefficient_val[1] << 8) | (coefficient_val[2]);
+
+ return conversion_coefficient;
+}
+
+
+
+uint32_t AltDevice::uncompensatedPressureTemperature(SPI_HandleTypeDef *spi_handle, GPIO_TypeDef *cs_port, uint16_t cs_pin, uint8_t conversion_command){
+
+ uint8_t digital_pres_temp[1] = {conversion_command};
+ uint8_t receive_buffer[1];
+
+ HAL_GPIO_WritePin(cs_port, cs_pin, GPIO_PIN_SET);
+ HAL_GPIO_WritePin(cs_port, cs_pin, GPIO_PIN_RESET);
+
+ /* send the digital pressure or temperature with the command */
+ HAL_SPI_TransmitReceive(spi_handle, digital_pres_temp, receive_buffer, 1, TIMEOUT);
+ HAL_GPIO_WritePin(cs_port, cs_pin, GPIO_PIN_SET);
+
+ /* at least 8.22 ms delay required for ADC conversion.*/
+ osDelay(9);
+
+ uint8_t tx_buffer[4] = {ADC_READ, 0xFF, 0xFF, 0xFF};
+ uint8_t rx_buffer[4];
+
+ HAL_GPIO_WritePin(cs_port, cs_pin, GPIO_PIN_RESET);
+
+ /*Start adc conversion to get value */
+ HAL_SPI_TransmitReceive(spi_handle, tx_buffer, rx_buffer, 4, TIMEOUT);
+
+ HAL_GPIO_WritePin(cs_port, cs_pin, GPIO_PIN_SET);
+
+ //get 24-bit uncompensated pressure or temperature value value.
+ uint32_t uncompensated_value = (rx_buffer[1] << 16 | rx_buffer[2] << 8 | rx_buffer[3]);
+
+ return uncompensated_value;
+}
+
+
+void AltDevice::calculateTempPres(SPI_HandleTypeDef *spi_handle, GPIO_TypeDef *cs_port, uint16_t cs_pin){
+
+
+ uint32_t digital_temperature = uncompensatedPressureTemperature(spi_handle, cs_port, cs_pin, CONVERT_D2_OSR_256);
+ uint32_t digital_pressure = uncompensatedPressureTemperature(spi_handle, cs_port, cs_pin, CONVERT_D1_OSR_256);
+
+ float dt = digital_temperature - (float)coeffs_.t_ref * 256.0f;
+ float temp = 2000 + dt * (float) coeffs_.temp_sens / pow(2, 23);
+
+
+ float off = coeffs_.off * 65536.0f + (coeffs_.tco * dt) / 128.0f;
+ float sens = coeffs_.sens * 32768.0f + (coeffs_.tcs * dt) / 256.0f;
+
+ /*Second order temperature compensation */
+ if(temp < 2000){
+ float t2 = (dt*dt) / 2147483648.0f;
+ float off2 = 5.0f * pow((temp - 2000), 2) / 2.0f;
+ float sens2 = 5.0f * pow((temp - 2000), 2) / 4.0f;
+
+
+ if(temp < 1500){
+ off2 = off2 + 7 * pow((temp + 1500), 2);
+ sens2 = sens2 + 11 * pow((temp + 1500), 2) / 2;
+ }
+
+ temp = temp - t2;
+ off = off - off2;
+ sens = sens - sens2;
+
+ }
+
+ float pressure = (digital_pressure * (sens / 2097152.0f) - off) / 32768.0f;
+ pressure /= 100.0f;
+ temp /= 100.0f;
+
+ pres_ = pressure;
+ temp_ = temp;
+}
+
+
+float AltDevice::getPressure(){
+ return pres_;
+}
+
+float AltDevice::getTemperature(){
+ return temp_;
+}
+
+float AltDevice::getAltAboveSeaLvl(){
+
+ float reference_temp = 288.15f; /* Ref temperature in Kelvins */
+ float temp_lapse_rate = 0.0065f;
+ float exp_gmrl = 5.2558;
+
+ float reference_pressure = 101325.0f; /* in Pa */
+ float current_pressure = getPressure() * 100.0f;
+ float exponent = (log(current_pressure) - log(reference_pressure)) / exp_gmrl;
+
+ float height = reference_temp/temp_lapse_rate * (1 - pow(M_E, exponent));
+
+ return height;
+}
+
+
+float AltDevice::getAltitude(){
+ height_ = getAltAboveSeaLvl();
+ return {height_ - base_elev_};
+}
+