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BLE_HTS_Demo
This BLE_HTS_Demo program enables you to collect Temperature and Humidity data reading from sensor and transmit to collector device such as smartphone.
Below documents teach you how to install app that can connect and read data from our DELTA-DFCM-NNN40 development board. There are two versions, Android and iPhone.
/media/uploads/Marcomissyou/ios_app_for_environment_sensor_0518.pdf
/media/uploads/Marcomissyou/android_app_for_environment_sensor.pdf
hts221.cpp
- Committer:
- silviaChen
- Date:
- 2017-07-18
- Revision:
- 10:5220f45c8ec1
- Parent:
- 9:2ff66a3d164a
File content as of revision 10:5220f45c8ec1:
/* Copyright (c) 2009 Nordic Semiconductor. All Rights Reserved. * * The information contained herein is property of Nordic Semiconductor ASA. * Terms and conditions of usage are described in detail in NORDIC * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT. * * Licensees are granted free, non-transferable use of the information. NO * WARRANTY of ANY KIND is provided. This heading must NOT be removed from * the file. *df */ #include <stdbool.h> #include <stdint.h> #include <mbed.h> #include "hts221.h" I2C i2c(SDA, SCL); //SDA, SCL /*lint ++flb "Enter library region" */ static const char expected_who_am_i = 0xBCU; //!< Expected value to get from WHO_AM_I register. uint8_t H0_rH_x2; uint8_t H1_rH_x2; uint16_t T0_degC_x8; uint16_t T1_degC_x8; int16_t H0_T0_OUT; int16_t H1_T0_OUT; int16_t T0_OUT; int16_t T1_OUT; float T0_DegC_cal; float T1_DegC_cal; float H0_RH_cal; float H1_RH_cal; bool hts221_init(void) { bool transfer_succeeded = true; i2c.frequency(400000); hts221_register_write(0x10 , TRes_4 << 3 | HRes_5); hts221_register_write(0x20 , PD_On | BDU_Off | ODR_1Hz); // Control register 1 hts221_register_write(0x21 , NoBoot | HeaterOff | No_OS); // Control register 2 hts221_register_write(0x22 , DRDY_H | PP_OD_PP | DRDY_NON); // Control register 3 // Read and verify product ID transfer_succeeded &= hts221_verify_product_id(); return transfer_succeeded; } bool hts221_verify_product_id(void) { char who_am_i[1]; hts221_register_read(ADDRESS_WHO_AM_I, &who_am_i[0], 1); if (who_am_i[0] != expected_who_am_i) return false; else return true; } void hts221_register_write(uint8_t register_address, uint8_t value) { char w2_data[2]; w2_data[0] = register_address; w2_data[1] = value; i2c.write(HTS221_WriteADDE, w2_data, 2); } void hts221_register_read(char register_address, char *destination, uint8_t number_of_bytes) { i2c.write(HTS221_WriteADDE, ®ister_address, 1, 1); i2c.read(HTS221_WriteADDE, destination, number_of_bytes); //Note by Tsungta, API may have a bug //runaboud read function added by Tsungta /* if (number_of_bytes == 1) { i2c.write(HTS221_WriteADDE, ®ister_address, 1, 1); i2c.write(HTS221_ReadADDE); *destination = i2c.read(0); i2c.stop(); } else { register_address |= 0x80; i2c.write(HTS221_WriteADDE, ®ister_address, 1, 1); i2c.write(HTS221_ReadADDE); while (number_of_bytes-- > 0) *destination++ = i2c.read(0); i2c.stop(); }*/ } void HTS221_Calib(void) { char cal_data[16]; hts221_register_read(0xB0, cal_data, 16); H0_rH_x2 = cal_data[0]; H1_rH_x2 = cal_data[1]; T0_degC_x8 = ((cal_data[5] & 0x03) << 8) + cal_data[2]; //MSB + LSB in T1_degC_x8 = ((cal_data[5] & 0x0C) << 6) + cal_data[3]; // MSB H0_T0_OUT = (cal_data[7] << 8) + cal_data[6]; H1_T0_OUT = (cal_data[11] << 8) + cal_data[10]; T0_OUT = (cal_data[13] << 8) + cal_data[12]; T1_OUT = (cal_data[15] << 8) + cal_data[14]; // convert negative 2's complement values to native negative value if (H0_T0_OUT&0x8000) H0_T0_OUT = -(0x8000-(0x7fff&H0_T0_OUT)); if (H1_T0_OUT&0x8000) H1_T0_OUT = -(0x8000-(0x7fff&H1_T0_OUT)); //((~H1_T0_OUT)+1);// if (T0_OUT&0x8000) T0_OUT = -(0x8000-(0x7fff&T0_OUT)); if (T1_OUT&0x8000) T1_OUT = -(0x8000-(0x7fff&T1_OUT)); T0_DegC_cal = (float) T0_degC_x8/8; T1_DegC_cal = (float) T1_degC_x8/8; H0_RH_cal = (float) H0_rH_x2/2; H1_RH_cal = (float) H1_rH_x2/2; } void HTS221_ReadTempHumi( float *pTemp , float *pHumi) { char sensor_data[4]; int16_t H_OUT; int16_t T_OUT; hts221_register_read(0xA8, sensor_data, 4); H_OUT = (sensor_data[1] << 8) + sensor_data[0]; T_OUT = (sensor_data[3] << 8) + sensor_data[2]; // convert negative 2's complement values to native negative value if (H_OUT&0x8000) H_OUT = -(0x8000-(0x7fff&H_OUT)); //((~H_OUT)+1);; if (T_OUT&0x8000) T_OUT = -(0x8000-(0x7fff&T_OUT)); *pTemp = linear_interpolation(T0_OUT, T0_DegC_cal, T1_OUT, T1_DegC_cal, T_OUT); *pHumi = linear_interpolation(H0_T0_OUT, H0_RH_cal, H1_T0_OUT, H1_RH_cal, H_OUT); // Constraint for measurement after calibration if ((int)*pHumi>MaxHumi-1 | (int)*pHumi==-72) *pHumi = MaxHumi; if ((int)*pHumi<MinHumi ) *pHumi = MinHumi; if ((int)*pTemp>MaxTemp-1) *pHumi = MaxTemp; if ((int)*pHumi<MinTemp ) *pHumi = MinTemp ; } float linear_interpolation(int16_t x0, float y0, int16_t x1, float y1, float mes) { float a = (float) ((y1 - y0) / (x1 - x0)); float b = (float) -a*x0 + y0; float cal = (float) a * mes + b; return cal; } /*lint --flb "Leave library region" */