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src/bme280.h

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+/**
+ * @file bme280.h
+ * @author marisa (marisa@fwmari.net)
+ * @brief BME280 helper
+ * @version 0.1
+ * @date 2024-05-06
+ *
+ * @copyright Copyright (c) 2024
+ *
+ */
+
+#pragma once
+
+#include <driver/i2c_master.h>
+#include <stdint.h>
+
+enum BME280Regs {
+  // Start of first calibration data registers
+  REG_CALIB00 = 0x88,
+
+  // Temperature calibration data registers
+  REG_T1 = 0x88,
+  REG_T2 = 0x8A,
+  REG_T3 = 0x8C,
+
+  // Pressure calibration data registers
+  REG_P1 = 0x8E,
+  REG_P2 = 0x90,
+  REG_P3 = 0x92,
+  REG_P4 = 0x94,
+  REG_P5 = 0x96,
+  REG_P6 = 0x98,
+  REG_P7 = 0x9A,
+  REG_P8 = 0x9C,
+  REG_P9 = 0x9E,
+
+  // Humidity calibration data registers
+  REG_H1 = 0xA1,
+  REG_H2 = 0xE1,
+  REG_H3 = 0xE3,
+  REG_E4 = 0xE4,
+  REG_E5 = 0xE5,
+  REG_E6 = 0xE6,
+  REG_H6 = 0xE7,
+
+  // Start of second calibration data registers
+  REG_CALIB26 = 0xE1,
+
+  // System registers
+  REG_CHIP_ID   = 0xD0,
+  REG_RESET     = 0xE0,
+  REG_CTRL_HUM  = 0xF2,
+  REG_STATUS    = 0xF3,
+  REG_CTRL_MEAS = 0xF4,
+  REG_CONFIG    = 0xF5,
+
+  // Start of raw data registers
+  REG_RAWDATA = 0xF7,
+  REG_P_MSB   = 0xF7,
+  REG_P_LSB   = 0xF8,
+  REG_P_XLSB  = 0xF9,
+  REG_T_MSB   = 0xFA,
+  REG_T_LSB   = 0xFB,
+  REG_T_XLSB  = 0xFC,
+  REG_H_MSB   = 0xFD,
+  REG_H_LSB   = 0xFE,
+};
+
+struct BME280CalibParams {
+  // Temperature trimming parameters
+  uint16_t t1;
+  int16_t  t2, t3;
+
+  // Pressure trimming parameters
+  uint16_t p1;
+  int16_t  p2, p3, p4, p5, p6, p7, p8, p9;
+
+  // Humidity trimming params
+  uint8_t h1;
+  int16_t h2;
+  int8_t  h3, h4, h5, h6;
+};
+
+struct BME280Reading {
+  double tempC, humidity, pressurehPa;
+};
+
+enum BME280Oversampling {
+  OVSP_X1 = 1,
+  OVSP_X2,
+  OVSP_X4,
+  OVSP_X8,
+  OVSP_X16,
+};
+
+struct BME280 {
+  struct BME280CalibParams calibParams;
+  enum BME280Oversampling  oversampling;
+  i2c_master_dev_handle_t  i2cHandle;
+};
+
+/**
+ * @brief Initializes BME280 struct. Creates i2c handle, sets oversampling and calibParams
+ *
+ * @param bme
+ */
+void BME280Init(struct BME280 *bme, enum BME280Oversampling oversampling);
+
+struct BME280Reading BME280Read(struct BME280 *bme);