humidity sensor SPI data readout

Core/Inc/bme280.h

@@ -0,0 +1,54 @@
+/*
+ * bme280.h
+ *
+ *  Created on: Jul. 23, 2022
+ *      Author: bossm
+ */
+
+#ifndef INC_BME280_H_
+#define INC_BME280_H_
+
+#include "main.h"
+#define MAX_RAW_HUM_BYTES 3
+#define MAX_RAW_TEMP_BYTES 3
+#define SPI_BUFF_LEN 5
+#define DOUBLE_BYTE_LEN 2
+
+const uint8_t ctrl_meas = 0x74;
+const uint8_t ctrl_hum = 0x72;
+const uint8_t config = 0x75;
+const uint8_t status = 0xF3;
+const uint8_t hum_msb = 0xFD;
+const uint8_t temp_msb = 0xFA;
+const uint8_t dig_h1_addr = 0xA1;
+const uint8_t dig_h2_addr = 0xE1;
+const uint8_t dig_h3_addr = 0xE3;
+const uint8_t dig_h4_addr = 0xE4;
+const uint8_t dig_h5_addr = 0xE5;
+const uint8_t dig_h6_addr = 0xE7;
+const uint8_t dig_t1_addr = 0x88;
+const uint8_t dig_t2_addr = 0x8A;
+const uint8_t dig_t3_addr = 0x8C;
+
+typedef int32_t bme280_s32_t;
+typedef uint32_t bme280_u32_t;
+bme280_s32_t t_fine, adc_t, adc_h;
+void bme280CompensateT(bme280_s32_t adc_t);
+bme280_u32_t bme280CompensateH(bme280_s32_t adc_h);
+
+uint8_t t1[DOUBLE_BYTE_LEN];
+uint16_t dig_t1;
+int8_t t2[DOUBLE_BYTE_LEN], t3[DOUBLE_BYTE_LEN], h2[DOUBLE_BYTE_LEN];
+int16_t dig_t2, dig_t3, dig_h2, dig_h4, dig_h5, dig_h4_ls[DOUBLE_BYTE_LEN], dig_h5_ls[DOUBLE_BYTE_LEN];
+unsigned char dig_h1, dig_h3, h6;
+char dig_h6;
+
+uint8_t spi_buff[SPI_BUFF_LEN];
+uint8_t hum_osrs = 0x1; //enable humidity with x1 oversampling
+uint8_t meas_val = 0x21; //set forced mode and turn off pressure
+uint8_t filter_off = 0x0;
+uint8_t hum_raw_val[MAX_RAW_HUM_BYTES];
+uint8_t temp_raw_val[MAX_RAW_TEMP_BYTES];
+HAL_StatusTypeDef ret;
+
+#endif /* INC_BME280_H_ */

Core/Src/bme280.c

@@ -0,0 +1,166 @@
+/*
+ * bme280.c
+ *
+ *  Created on: Jul. 23, 2022
+ *      Author: bossm
+ */
+
+#include "bme280.h"
+#include <string.h>
+
+bme280_u32_t bme280(SPI_HandleTypeDef hspi2){
+	//select mode 0
+	HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_RESET);
+	HAL_GPIO_WritePin(GPIOB, GPIO_PIN_10, GPIO_PIN_SET);
+
+	//write settings
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&ctrl_hum, 1, 100);
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&hum_osrs, 1, 100);
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&ctrl_meas, 1, 100);
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&meas_val, 1, 100);
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&config, 1, 100);
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&filter_off, 1, 100);
+	HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_SET);
+
+	memset(spi_buff, 0, sizeof(spi_buff));
+	spi_buff[0]=1;
+
+	//check status
+	while(spi_buff[0] & (1<<3)){ //bit masking need bit 3
+		HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_RESET);
+		HAL_GPIO_WritePin(GPIOB, GPIO_PIN_10, GPIO_PIN_SET);
+		HAL_SPI_Transmit(&hspi2, (uint8_t *)&status, 1, 100);
+		HAL_SPI_Receive(&hspi2, (uint8_t *)spi_buff, 1, 100);
+		HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_SET);
+	}
+
+	//read hum data
+	HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_RESET);
+	HAL_GPIO_WritePin(GPIOB, GPIO_PIN_10, GPIO_PIN_SET);
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&hum_msb, 1, 100);
+	ret = HAL_SPI_Receive(&hspi2, (uint8_t *)hum_raw_val, 2, 100);
+	while(ret != HAL_OK){
+		ret = HAL_SPI_Receive(&hspi2, (uint8_t *)hum_raw_val, 2, 100);
+	}
+	HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_SET);
+	adc_h = (hum_raw_val[1]>>8)|(hum_raw_val[0]);
+
+	//read temp data
+	HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_RESET);
+	HAL_GPIO_WritePin(GPIOB, GPIO_PIN_10, GPIO_PIN_SET);
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&temp_msb, 1, 100);
+	ret = HAL_SPI_Receive(&hspi2, (uint8_t *)temp_raw_val, 1, 100);
+	while(ret != HAL_OK){
+		ret = HAL_SPI_Receive(&hspi2, (uint8_t *)temp_raw_val, 1, 100);
+	}
+	HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_SET);
+
+	//correct temp data
+	adc_t = (temp_raw_val[2] >> 24)|(temp_raw_val[1] >> 21)|temp_raw_val[0];
+
+	//read data
+	HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_RESET);
+	HAL_GPIO_WritePin(GPIOB, GPIO_PIN_10, GPIO_PIN_SET);
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&dig_t1_addr, 1, 100);
+	ret = HAL_SPI_Receive(&hspi2, (uint8_t *)t1, 2, 100);
+	while(ret != HAL_OK){
+		ret = HAL_SPI_Receive(&hspi2, (uint8_t *)t1, 2, 100);
+	}
+
+	dig_t1 = (t1[1] << 8) | t1[0];
+
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&dig_t2_addr, 1, 100);
+	ret = HAL_SPI_Receive(&hspi2, (uint8_t *)t2, 2, 100);
+	while(ret != HAL_OK){
+		ret = HAL_SPI_Receive(&hspi2, (uint8_t *)t2, 2, 100);
+	}
+
+	dig_t2 = (int)(t2[1] << 8) | (int) t2[0];
+
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&dig_t3_addr, 1, 100);
+	ret = HAL_SPI_Receive(&hspi2, (uint8_t *)t3, 2, 100);
+	while(ret != HAL_OK){
+		ret = HAL_SPI_Receive(&hspi2, (uint8_t *)t3, 2, 100);
+	}
+
+	dig_t3 = (int) ((t3[1] << 8) | t3[0]);
+
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&dig_h1_addr, 1, 100);
+	ret = HAL_SPI_Receive(&hspi2, (unsigned char *)&dig_h1, 1, 100);
+	while(ret != HAL_OK){
+		ret = HAL_SPI_Receive(&hspi2, (unsigned char *)&dig_h1, 1, 100);
+	}
+
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&dig_h2_addr, 1, 100);
+	ret = HAL_SPI_Receive(&hspi2, (uint8_t *)h2, 2, 100);
+	while(ret != HAL_OK){
+		ret = HAL_SPI_Receive(&hspi2, (uint8_t *)h2, 2, 100);
+	}
+
+	dig_h2 = (int) ((h2[1] << 8) | h2[0]);
+
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&dig_h3_addr, 1, 100);
+	ret = HAL_SPI_Receive(&hspi2, (unsigned char *)&dig_h3, 1, 100);
+	while(ret != HAL_OK){
+		ret = HAL_SPI_Receive(&hspi2, (unsigned char *)&dig_h3, 1, 100);
+	}
+
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&dig_h4_addr, 1, 100);
+	ret = HAL_SPI_Receive(&hspi2, (uint8_t *)dig_h4_ls, 2, 100);
+	while(ret != HAL_OK){
+		ret = HAL_SPI_Receive(&hspi2, (uint8_t *)dig_h4_ls, 2, 100);
+	}
+
+	dig_h4_ls[1] = dig_h4_ls[1] & 0xF;
+	dig_h4 = (int) (dig_h4_ls[0] | dig_h4_ls[1]);
+
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&dig_h5_addr, 1, 100);
+	ret = HAL_SPI_Receive(&hspi2, (uint8_t *)dig_h5_ls, 2, 100);
+	while(ret != HAL_OK){
+		ret = HAL_SPI_Receive(&hspi2, (uint8_t *)dig_h5_ls, 2, 100);
+	}
+
+	dig_h5_ls[0] = (dig_h5_ls[0] & 0xF000) >> 12;
+	dig_h5_ls[1] = dig_h5_ls[1] << 8;
+	dig_h5 = (int) (dig_h5_ls[1] | dig_h5_ls[0]);
+
+	HAL_SPI_Transmit(&hspi2, (uint8_t *)&dig_h6_addr, 1, 100);
+	ret = HAL_SPI_Receive(&hspi2, (unsigned char *)&h6, 1, 100);
+	while(ret != HAL_OK){
+		ret = HAL_SPI_Receive(&hspi2, (unsigned char *)&h6, 1, 100);
+	}
+
+	dig_h6 = (char) h6;
+
+	HAL_GPIO_WritePin(GPIOB, GPIO_PIN_12, GPIO_PIN_SET);
+
+	return bme280CompensateH(adc_h);
+}
+
+// Returns temperature in DegC, resolution is 0.01 DegC. Output value of “5123” equals 51.23 DegC.
+// t_fine carries fine temperature as global value
+void bme280CompensateT(bme280_s32_t adc_t){
+	bme280_s32_t var1, var2;
+	var1 = ((((adc_t>>3) - ((bme280_s32_t)dig_t1<<1))) * ((bme280_s32_t)dig_t2)) >> 11;
+	var2 = (((((adc_t>>4) - ((bme280_s32_t)dig_t1)) * ((adc_t>>4) - ((bme280_s32_t)dig_t1))) >> 12) *
+	((bme280_s32_t)dig_t3)) >> 14;
+	t_fine = var1 + var2;
+	//T = (t_fine * 5 + 128) >> 8;
+	//return T;
+}
+
+// Returns humidity in %RH as unsigned 32 bit integer in Q22.10 format (22 integer and 10 fractional bits).
+// Output value of “47445” represents 47445/1024 = 46.333 %RH
+bme280_u32_t bme280CompensateH(bme280_s32_t adc_h){
+	bme280CompensateT(adc_t);
+	bme280_s32_t v_x1_u32r;
+	v_x1_u32r = (t_fine - ((bme280_s32_t)76800));
+	v_x1_u32r = (((((adc_h << 14) - (((bme280_s32_t)dig_h4) << 20) - (((bme280_s32_t)dig_h5) * v_x1_u32r)) +
+	((bme280_s32_t)16384)) >> 15) * (((((((v_x1_u32r * ((bme280_s32_t)dig_h6)) >> 10) * (((v_x1_u32r *
+	((bme280_s32_t)dig_h3)) >> 11) + ((bme280_s32_t)32768))) >> 10) + ((bme280_s32_t)2097152)) *
+	((bme280_s32_t)dig_h2) + 8192) >> 14));
+	v_x1_u32r = (v_x1_u32r - (((((v_x1_u32r >> 15) * (v_x1_u32r >> 15)) >> 7) * ((bme280_s32_t)dig_h1)) >> 4));
+	v_x1_u32r = (v_x1_u32r < 0 ? 0 : v_x1_u32r);
+	v_x1_u32r = (v_x1_u32r > 419430400 ? 419430400 : v_x1_u32r);
+	return (bme280_u32_t)(v_x1_u32r>>12);
+}