Basic untested LIS3MDLTR magnetometer singleton driver functionality

Components/LIS3MDLTRDriver.cpp

@@ -0,0 +1,153 @@
+/*
+ * IMUDriver.cpp
+ *
+ *  Created on: Aug 31, 2024
+ *      Author: goada
+ */
+
+#include <LIS3MDLTRDriver.h>
+
+/* @brief Initialize the driver. Must be called before any other functions can be used.
+ * @param hspi_ Pointer to the SPI handle
+ * @param cs_gpio_ GPIO port for the chip select pin (GPIOA, GPIOB ...)
+ * @param cs_pin_ Pin number for the chip select
+ */
+void LIS3MDLTR_Driver::Init(SPI_HandleTypeDef* hspi_, GPIO_TypeDef* cs_gpio_, uint16_t cs_pin_) {
+	hspi = hspi_;
+	initialized = true;
+	SetCSPin(cs_gpio_, cs_pin_);
+	CSHigh();
+
+	uint8_t ID = GetRegister(LIS3MDLTR_REG::WHO_AM_I);
+	if(ID != LIS3MDLTR_ID) {
+		// couldn't get chip ID
+		initialized = false;
+		return;
+	}
+	// Enable temp and max speed
+	SetRegister(LIS3MDLTR_REG::CTRL_REG1, 0b11111110);
+
+	// Leave power-down mode
+	SetRegister(LIS3MDLTR_REG::CTRL_REG3, 0b00000000);
+
+	// High-performance z axis
+	SetRegister(LIS3MDLTR_REG::CTRL_REG4, 0b00001100);
+
+}
+
+/* @brief Sets a single 8-bit register.
+ * @param reg The register to set. Constants contained in ICM20948_REG namespace.
+ * @param val Value to set the register to.
+ * @return Success
+ */
+bool LIS3MDLTR_Driver::SetRegister(LIS3MDLTR_REGISTER_t reg, uint8_t val) {
+	assert(initialized);
+
+	uint8_t data[2] = {(uint8_t)(0b00000000 | (reg&0x3F)),val};
+	CSLow();
+	HAL_StatusTypeDef r = HAL_SPI_Transmit(hspi, data, 2, 1000);
+	CSHigh();
+	return r == HAL_OK;
+
+}
+
+/* @brief Gets a single 8-bit register.
+ * @param reg The register to get. Constants contained in ICM20948_REG namespace.
+ * @return Value read from the register.
+ */
+uint8_t LIS3MDLTR_Driver::GetRegister(LIS3MDLTR_REGISTER_t reg) {
+	assert(initialized);
+	uint8_t data[2] = {(uint8_t)(0b10000000 | (reg&0x3F)),SPI_DUMMY_BYTE};
+	uint8_t incoming[2] = {0,0};
+	CSLow();
+	HAL_SPI_TransmitReceive(hspi, data, incoming, 2, 1000);
+	CSHigh();
+	return incoming[1];
+}
+
+/* @brief Reads multiple successive registers in a row.
+ * @param startreg The register that the readings should start at.
+ * @param numBytes Number of bytes to read.
+ * @param out Address of buffer to receive data. Must be numBytes long.
+ */
+void LIS3MDLTR_Driver::GetMultipleRegisters(LIS3MDLTR_REGISTER_t startreg, int numBytes,
+		uint8_t *out) {
+	assert(initialized);
+
+	uint8_t transmit[numBytes+1] = {SPI_DUMMY_BYTE};
+	transmit[0] = (uint8_t)(0b11000000 | (startreg&0x3f));
+
+	CSLow();
+	HAL_SPI_TransmitReceive(hspi, transmit, out, numBytes+1, 1000);
+	CSHigh();
+}
+
+
+/* @brief Extract IMU data from a raw byte buffer (such as from ReadAllSensorRegs) into a struct.
+ * @param temp Buffer includes temperature data
+ * @return Struct containing extracted data
+ */
+const LIS3MDLTR_DATA_t LIS3MDLTR_Driver::GetDataFromBuf(const uint8_t *buf, bool mag, bool temp) {
+	LIS3MDLTR_DATA_t out;
+	size_t i = 0;
+
+	//both little-endian
+	if(mag) {
+		out.mag.x = (buf[i]) | (buf[1+1]<<8);
+		out.mag.y = (buf[i+2]) | (buf[1+3]<<8);
+		out.mag.z = (buf[i+4]) | (buf[1+5]<<8);
+	}
+	if(temp) {
+		out.temp = (buf[i]) | (buf[i+1]<<8);
+		i += 2;
+	}
+
+	return out;
+
+}
+
+/* @brief Reads all 8 sensor registers in order. (mag, temp)
+ * @param out Raw bytes read from registers. Must be 8 bytes long
+ */
+void LIS3MDLTR_Driver::GetMeasurements(uint8_t* out) {
+	GetMultipleRegisters(LIS3MDLTR_REG::OUTX_L, 8, out);
+}
+
+
+LIS3MDLTR_Driver::LIS3MDLTR_Driver() {
+}
+
+LIS3MDLTR_Driver::~LIS3MDLTR_Driver() {
+}
+
+void LIS3MDLTR_Driver::CSLow() {
+	assert(initialized);
+	HAL_GPIO_WritePin(cs_gpio, cs_pin, GPIO_PIN_RESET);
+}
+
+void LIS3MDLTR_Driver::SetCSPin(GPIO_TypeDef* gpio, uint16_t pin) {
+	cs_gpio = gpio;
+	cs_pin = pin;
+}
+
+void LIS3MDLTR_Driver::EnableTemp() {
+	SetRegister(LIS3MDLTR_REG::CTRL_REG1, GetRegister(LIS3MDLTR_REG::CTRL_REG1) | 0b10000000);
+}
+
+void LIS3MDLTR_Driver::DisableTemp() {
+	SetRegister(LIS3MDLTR_REG::CTRL_REG1, GetRegister(LIS3MDLTR_REG::CTRL_REG1) & 0b01111111);
+}
+
+void LIS3MDLTR_Driver::CSHigh() {
+	assert(initialized);
+	HAL_GPIO_WritePin(cs_gpio, cs_pin, GPIO_PIN_SET);
+}
+/* @brief Gets the temperature. Must have temperature enabled with EnableTemp.
+ * @return Temperature in Celsius.
+ */
+uint16_t GetTemp() {
+	uint8_t tempbyte[2];
+	GetMultipleRegisters(LIS3MDLTR_REG::OUT_TEMP_L,2,tempbyte);
+	uint16_t temp = (tempbyte[0])|(tempbyte[1]<<8);
+	return 25+temp/8;
+}

Components/LIS3MDLTRDriver.h

@@ -0,0 +1,98 @@
+/*
+ * IMUDriver.h
+ *
+ *  Created on: Aug 31, 2024
+ *      Author: goada
+ */
+
+#ifndef LIS3MDLTRDRIVER_H_
+#define LIS3MDLTRDRIVER_H_
+
+#include "stm32h7xx.h"
+
+constexpr uint8_t SPI_DUMMY_BYTE = 0x00;
+constexpr uint8_t LIS3MDLTR_ID = 0b00111101;
+
+typedef uint8_t LIS3MDLTR_REGISTER_t;
+
+struct MAG_t {
+	int16_t x;
+	int16_t y;
+	int16_t z;
+};
+
+struct LIS3MDLTR_DATA_t {
+	MAG_t mag;
+	int16_t temp;
+};
+
+/* @brief Singleton SPI driver for the LIS3MDLTR magnetometer.
+ * Must call Init before using any other functions besides SetCSPin.
+ * SPI max clock speed 10MHz.
+ */
+class LIS3MDLTR_Driver {
+public:
+	LIS3MDLTR_Driver();
+	~LIS3MDLTR_Driver();
+
+	static LIS3MDLTR_Driver& Inst() {
+		static LIS3MDLTR_Driver inst;
+		return inst;
+	}
+
+	void Init(SPI_HandleTypeDef* hspi, GPIO_TypeDef* cs_gpio_, uint16_t cs_pin_);
+
+	bool SetRegister(LIS3MDLTR_REGISTER_t reg, uint8_t val);
+	uint8_t GetRegister(LIS3MDLTR_REGISTER_t reg);
+	void GetMultipleRegisters(LIS3MDLTR_REGISTER_t startreg, int numBytes, uint8_t* out);
+	void GetMeasurements(uint8_t* out);
+
+	void EnableTemp();
+	void DisableTemp();
+
+	uint16_t GetTemp();
+
+	LIS3MDLTR_Driver(const LIS3MDLTR_Driver&) = delete;
+	LIS3MDLTR_Driver& operator=(const LIS3MDLTR_Driver&) = delete;
+
+	const LIS3MDLTR_DATA_t GetDataFromBuf(const uint8_t *buf, bool mag = true, bool temp = true);
+
+	void SetCSPin(GPIO_TypeDef* gpio, uint16_t pin);
+
+private:
+	bool initialized = false;
+	SPI_HandleTypeDef* hspi = nullptr;
+	GPIO_TypeDef* cs_gpio;
+	uint16_t cs_pin;
+
+	void CSLow();
+	void CSHigh();
+
+};
+
+// Constant addresses for registers in the LIS3MDLTR magnetometer
+namespace LIS3MDLTR_REG {
+
+	constexpr LIS3MDLTR_REGISTER_t WHO_AM_I  = 0x0F;
+
+	constexpr LIS3MDLTR_REGISTER_t CTRL_REG1  = 0x20;
+	constexpr LIS3MDLTR_REGISTER_t CTRL_REG2  = 0x21;
+	constexpr LIS3MDLTR_REGISTER_t CTRL_REG3  = 0x22;
+	constexpr LIS3MDLTR_REGISTER_t CTRL_REG4  = 0x23;
+	constexpr LIS3MDLTR_REGISTER_t CTRL_REG5  = 0x24;
+
+	constexpr LIS3MDLTR_REGISTER_t STATUS_REG    = 0x27;
+
+	constexpr LIS3MDLTR_REGISTER_t OUT_TEMP_L    = 0x2E;
+	constexpr LIS3MDLTR_REGISTER_t OUT_TEMP_H    = 0x2F;
+
+	constexpr LIS3MDLTR_REGISTER_t OUTX_L    = 0x28;
+	constexpr LIS3MDLTR_REGISTER_t OUTX_H    = 0x29;
+	constexpr LIS3MDLTR_REGISTER_t OUTY_L    = 0x2A;
+	constexpr LIS3MDLTR_REGISTER_t OUTY_H    = 0x2B;
+	constexpr LIS3MDLTR_REGISTER_t OUTZ_L    = 0x2C;
+	constexpr LIS3MDLTR_REGISTER_t OUTZ_H    = 0x2D;
+
+}
+
+#endif /* LIS3MDLTRDRIVER_H_ */