ds1775_c.cpp

00001 /*******************************************************************************
00002 * Copyright (C) 2019 Maxim Integrated Products, Inc., All Rights Reserved.
00003 *
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00010 *
00011 * The above copyright notice and this permission notice shall be included
00012 * in all copies or substantial portions of the Software.
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00016 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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00021 *
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00025 *
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00032 */
00033 #include "ds1775.h"
00034 #include "ds1775_c.h"
00035 #include "mbed.h" 
00036 // #include "USBSerial.h"
00037 
00038 
00039 /******************************************************************************/
00040 /*  C version for DS1775 driver                                             */
00041 /******************************************************************************/
00042 
00043 /* @var ds1775_write_address, ds1775_read_address
00044  * @brief I2C address
00045  */
00046 uint8_t ds1775_write_address, ds1775_read_address;
00047 
00048 int ds1775_init(uint8_t slave_address)
00049 {
00050     ds1775_write_address = (slave_address <<1);
00051     ds1775_read_address = ((slave_address << 1) | 1);
00052     return DS1775_NO_ERROR;
00053 }
00054  
00055 /******************************************************************************/
00056 int ds1775_read_cfg_reg(uint8_t *value, I2C &i2c_bus)
00057 {
00058     int32_t ret;
00059     char data[1] = {0};
00060     char reg = DS1775_REG_CONFIGURATION;
00061 
00062     /* write to the Register Select, true is for repeated start */
00063     ret = i2c_bus.write(ds1775_write_address, &reg, 1, true);
00064     if (ret == 0) {
00065         ret = i2c_bus.read(ds1775_read_address, data, 1, false);
00066         if (ret == 0) {
00067             *value = data[0];
00068             return DS1775_NO_ERROR;
00069         } else {
00070             printf("%s: failed to read data: ret: %d\r\n", __func__, ret);
00071             }
00072     } else {                
00073         printf("%s: failed to write to Register Select: ret: %d\r\n",
00074             __func__, ret);
00075     }
00076     return DS1775_ERROR;
00077 }
00078 
00079 
00080 /******************************************************************************/
00081 int ds1775_read_reg16(int16_t *value, char reg, I2C &i2c_bus) 
00082 {
00083     int32_t ret;
00084     char data[2] = {0, 0};
00085     ds1775_raw_data tmp;
00086      
00087     if (reg == DS1775_REG_TEMPERATURE || 
00088         reg == DS1775_REG_THYST_LOW_TRIP || reg == DS1775_REG_TOS_HIGH_TRIP) {
00089         /* write to the Register Select, true is for repeated start */
00090         ret = i2c_bus.write(ds1775_write_address, &reg, 1, true);
00091         /* read the two bytes of data */
00092         if (ret == 0) {
00093             ret = i2c_bus.read(ds1775_read_address, data, 2, false);
00094             if (ret == 0) {
00095                 tmp.msb = data[0];
00096                 tmp.lsb = data[1];
00097                 *value = tmp.swrd;
00098                 return DS1775_NO_ERROR;
00099             } else {
00100                 printf(
00101                     "%s: failed to read data: ret: %d\r\n", __func__, ret);
00102             }
00103         } else {                
00104             printf("%s: failed to write to Register Select: ret: %d\r\n",
00105                 __func__, ret);
00106         }
00107     } else {
00108         printf("%s: register address is not correct: register: %d\r\n",
00109                 __func__, reg);
00110     }                
00111     return DS1775_ERROR;
00112 }
00113 
00114 float ds1775_read_reg_as_temperature(uint8_t reg, I2C &i2c_bus)
00115 {
00116     ds1775_raw_data tmp;
00117     float temperature;
00118     if (reg == DS1775_REG_TEMPERATURE ||
00119         reg == DS1775_REG_THYST_LOW_TRIP || reg == DS1775_REG_TOS_HIGH_TRIP) {
00120         ds1775_read_reg16(&tmp.swrd, reg, i2c_bus);
00121         temperature = (float)tmp.swrd;  /* values are 2's complement */
00122         temperature *= DS1775_CF_LSB;
00123         return temperature;
00124     } else {
00125         printf("%s: register is invalid, %d r\n", __func__, reg);
00126         return 0;
00127     }
00128 }
00129 
00130 
00131 /******************************************************************************/
00132 int ds1775_write_reg16(int16_t value, char reg, I2C &i2c_bus) 
00133 {
00134     int32_t ret;
00135     char cmd[3];
00136     ds1775_raw_data tmp;
00137 
00138     if (reg >= DS1775_REG_THYST_LOW_TRIP && reg <= DS1775_REG_MAX) {
00139         cmd[0] = reg;
00140         tmp.swrd = value;
00141         cmd[1] = tmp.msb;
00142         cmd[2] = tmp.lsb;
00143         ret = i2c_bus.write(ds1775_write_address, cmd, 3, false);
00144         if (ret == 0) {
00145             return DS1775_NO_ERROR;
00146         } else {
00147             printf("%s: I2C write error %d\r\n",__func__, ret);
00148             return DS1775_ERROR;
00149         }
00150     } else {
00151         printf("%s: register value invalid %x\r\n",__func__, reg);
00152         return DS1775_ERROR;
00153     }
00154 }
00155 
00156 
00157 int ds1775_write_cfg_reg(uint8_t cfg, I2C &i2c_bus)
00158 {
00159     int32_t ret;
00160     char cmd[2];
00161 
00162     cmd[0] = DS1775_REG_CONFIGURATION;
00163     cmd[1] = cfg;
00164     ret = i2c_bus.write(ds1775_write_address, cmd, 2, false);
00165     if (ret == 0) {
00166         return DS1775_NO_ERROR;
00167     } else {
00168         printf("%s: I2C write error %d\r\n",__func__, ret);
00169         return DS1775_ERROR;
00170     }
00171 }
00172 
00173 
00174 int ds1775_write_trip_low_thyst(float temperature, I2C &i2c_bus)
00175 {
00176     ds1775_raw_data raw;
00177     temperature /= DS1775_CF_LSB;
00178     raw.swrd = int16_t(temperature);
00179     return ds1775_write_reg16(raw.swrd, DS1775_REG_THYST_LOW_TRIP, i2c_bus);
00180 }
00181 
00182 
00183 int ds1775_write_trip_high_tos(float temperature, I2C &i2c_bus)
00184 {
00185     ds1775_raw_data raw;
00186     temperature /= DS1775_CF_LSB;
00187     raw.swrd = int16_t(temperature);
00188     return ds1775_write_reg16(raw.swrd, DS1775_REG_TOS_HIGH_TRIP, i2c_bus);
00189 }
00190 
00191 
00192 float ds1775_celsius_to_fahrenheit(float temp_c)
00193 {
00194     float temp_f;
00195     temp_f = ((temp_c * 9)/5) + 32;
00196     return temp_f;
00197 }