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-rw-r--r--src/temperature/bmp085.c245
1 files changed, 245 insertions, 0 deletions
diff --git a/src/temperature/bmp085.c b/src/temperature/bmp085.c
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+++ b/src/temperature/bmp085.c
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+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Matthias P. Braendli, Maximilien Cuony
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+*/
+
+#include "FreeRTOS.h"
+#include "task.h"
+#include "bmp085.h"
+#include "i2c.h"
+#include "debug.h"
+#include <stdio.h>
+
+const uint8_t mode = BMP085_MODE_ULTRAHIGHRES;
+
+static int init_ok = 0;
+static bmp085_calib_data_t bmp085_coeffs;
+
+static int bmp085_raw_temp(int32_t *raw_temp);
+static int bmp085_raw_pressure(int32_t *raw_pressure);
+static int read_u16(uint8_t reg, uint16_t *value);
+static int read_s16(uint8_t reg, int16_t *value);
+
+int read_u16(uint8_t reg, uint16_t *value)
+{
+ int success = 0;
+ if (i2c_transaction_start()) {
+ success = i2c_read_from(BMP085_ADDRESS, reg, (uint8_t*)value, 2) > 0;
+ i2c_transaction_end();
+ }
+ else {
+ debug_print("read_u16 no transaction!\n");
+ }
+ return success;
+}
+
+int read_s16(uint8_t reg, int16_t *value) {
+ uint16_t v;
+ int success = read_u16(reg, &v);
+ *value = (int16_t)v;
+ return success;
+}
+
+static void print_s16(const char *hdr, int16_t value) {
+ char t[32];
+ snprintf(t, 32, "%s=%d\n", hdr, value);
+ debug_print(t);
+}
+
+static void print_s32(const char *hdr, int32_t value) {
+ char t[32];
+ snprintf(t, 32, "%s=%ld\n", hdr, value);
+ debug_print(t);
+}
+
+static void print_u16(const char *hdr, uint16_t value) {
+ char t[32];
+ snprintf(t, 32, "%s=%d\n", hdr, value);
+ debug_print(t);
+}
+
+int bmp085_init() {
+ uint8_t id = 0;
+
+ int success = 0;
+ if (i2c_transaction_start()) {
+ success = i2c_read_from(BMP085_ADDRESS, BMP085_REGISTER_CHIPID, &id, 1) > 0;
+ i2c_transaction_end();
+ }
+ else {
+ debug_print("bmp085_init no transaction");
+ }
+
+ if (success == 0 || id != 0x55) {
+ return 0;
+ }
+
+ success &= read_s16(BMP085_REGISTER_CAL_AC1, &bmp085_coeffs.ac1);
+ success &= read_s16(BMP085_REGISTER_CAL_AC2, &bmp085_coeffs.ac2);
+ success &= read_s16(BMP085_REGISTER_CAL_AC3, &bmp085_coeffs.ac3);
+ success &= read_u16(BMP085_REGISTER_CAL_AC4, &bmp085_coeffs.ac4);
+ success &= read_u16(BMP085_REGISTER_CAL_AC5, &bmp085_coeffs.ac5);
+ success &= read_u16(BMP085_REGISTER_CAL_AC6, &bmp085_coeffs.ac6);
+ success &= read_s16(BMP085_REGISTER_CAL_B1, &bmp085_coeffs.b1);
+ success &= read_s16(BMP085_REGISTER_CAL_B2, &bmp085_coeffs.b2);
+ success &= read_s16(BMP085_REGISTER_CAL_MB, &bmp085_coeffs.mb);
+ success &= read_s16(BMP085_REGISTER_CAL_MC, &bmp085_coeffs.mc);
+ success &= read_s16(BMP085_REGISTER_CAL_MD, &bmp085_coeffs.md);
+
+ print_s16("AC1", bmp085_coeffs.ac1);
+ print_s16("AC2", bmp085_coeffs.ac2);
+ print_s16("AC3", bmp085_coeffs.ac3);
+ print_u16("AC4", bmp085_coeffs.ac4);
+ print_u16("AC5", bmp085_coeffs.ac5);
+ print_u16("AC6", bmp085_coeffs.ac6);
+ print_s16("B1", bmp085_coeffs.b1);
+ print_s16("B2", bmp085_coeffs.b2);
+ print_s16("MB", bmp085_coeffs.mb);
+ print_s16("MC", bmp085_coeffs.mc);
+ print_s16("MD", bmp085_coeffs.md);
+
+ init_ok = success;
+ return success;
+}
+
+
+int bmp085_raw_temp(int32_t *raw_temp)
+{
+ int success = 1;
+ const uint8_t data[2] = {BMP085_REGISTER_CONTROL, BMP085_COMMAND_READTEMP};
+ if (i2c_transaction_start()) {
+ success &= i2c_write(BMP085_ADDRESS, data, 2);
+ i2c_transaction_end();
+ }
+ else {
+ return 0;
+ }
+
+ vTaskDelay(15 / portTICK_PERIOD_MS);
+
+ uint16_t t;
+ success &= read_u16(BMP085_REGISTER_TEMPDATA, &t);
+ *raw_temp = t;
+ return success;
+}
+
+int bmp085_raw_pressure(int32_t *raw_pressure)
+{
+ int success = 1;
+
+ const uint8_t data[2] = {BMP085_REGISTER_CONTROL, BMP085_COMMAND_READPRESSURE | (mode << 6)};
+ if (i2c_transaction_start()) {
+ success &= i2c_write(BMP085_ADDRESS, data, 2);
+ i2c_transaction_end();
+ }
+ else {
+ return 0;
+ }
+
+ int delay = 0;
+ switch (mode) {
+ case BMP085_MODE_ULTRALOWPOWER:
+ delay = 5;
+ break;
+ case BMP085_MODE_STANDARD:
+ delay = 8;
+ break;
+ case BMP085_MODE_HIGHRES:
+ delay = 14;
+ break;
+ case BMP085_MODE_ULTRAHIGHRES:
+ default:
+ delay = 26;
+ break;
+ }
+ vTaskDelay(3*delay / portTICK_PERIOD_MS);
+
+ uint8_t p8;
+ uint16_t p16;
+ int32_t p32;
+
+ success &= read_u16(BMP085_REGISTER_PRESSUREDATA, &p16);
+ p32 = (uint32_t)p16 << 8;
+
+ if (i2c_transaction_start()) {
+ success &= i2c_read_from(BMP085_ADDRESS, BMP085_REGISTER_PRESSUREDATA+2, &p8, 1) > 0;
+ i2c_transaction_end();
+ }
+ p32 += p8;
+ p32 >>= (8 - mode);
+ *raw_pressure = p32;
+ return success;
+}
+
+int bmp085_get_temp_pressure(int32_t *temperature_deciDeg, int32_t *pressure_Pa)
+{
+ if (!init_ok) {
+ return 0;
+ }
+
+ int32_t compp = 0;
+ int32_t x1, x2, b5, b6, x3, b3, p;
+ uint32_t b4, b7;
+
+ int32_t ut = 0;
+ int success = bmp085_raw_temp(&ut);
+ print_s32("ut", ut);
+ int32_t up = 0;
+ success &= bmp085_raw_pressure(&up);
+ print_s32("up", up);
+
+ /* Temperature compensation */
+ int32_t X1 = (ut - (int32_t)bmp085_coeffs.ac6) * ((int32_t)bmp085_coeffs.ac5) >> 15;
+ int32_t X2 = ((int32_t)bmp085_coeffs.mc << 11) / (X1+(int32_t)bmp085_coeffs.md);
+ b5 = X1 + X2;
+ int32_t temp = (b5 + 8) >> 4;
+ *temperature_deciDeg = temp;
+
+ /* Pressure compensation */
+ b6 = b5 - 4000;
+ x1 = (bmp085_coeffs.b2 * ((b6 * b6) >> 12)) >> 11;
+ x2 = (bmp085_coeffs.ac2 * b6) >> 11;
+ x3 = x1 + x2;
+ b3 = (((((int32_t) bmp085_coeffs.ac1) * 4 + x3) << mode) + 2) >> 2;
+ x1 = (bmp085_coeffs.ac3 * b6) >> 13;
+ x2 = (bmp085_coeffs.b1 * ((b6 * b6) >> 12)) >> 16;
+ x3 = ((x1 + x2) + 2) >> 2;
+ b4 = (bmp085_coeffs.ac4 * (uint32_t) (x3 + 32768)) >> 15;
+ b7 = ((uint32_t) (up - b3) * (50000 >> mode));
+
+ if (b7 < 0x80000000) {
+ p = (b7 << 1) / b4;
+ }
+ else {
+ p = (b7 / b4) << 1;
+ }
+
+ x1 = (p >> 8) * (p >> 8);
+ x1 = (x1 * 3038) >> 16;
+ x2 = (-7357 * p) >> 16;
+ compp = p + ((x1 + x2 + 3791) >> 4);
+
+ /* Assign compensated pressure value */
+ *pressure_Pa = compp;
+
+ return success;
+}
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