hdc1080.h

00001 /*
00002   By Joseph Ellsworth CTO of A2WH
00003   Take a look at A2WH.com Producing Water from Air using Solar Energy
00004   March-2016 License: https://developer.mbed.org/handbook/MIT-Licence
00005   Please contact us http://a2wh.com for help with custom design projects.
00006 
00007   See Also:
00008     http://www.ti.com/lit/ds/symlink/hdc1080.pdf
00009     https://github.com/closedcube/ClosedCube_HDC1080_Arduino/blob/master/src/ClosedCube_HDC1080.cpp
00010     http://e.pavlin.si/2016/06/04/hdlc-like-data-link-via-rs485/
00011 */
00012 
00013 /**
00014 #include "mbed.h"
00015 #include <stdint.h>
00016 
00017 //Pin Defines for I2C Bus
00018 #define D_SDA                  PB_7 // specific for Nucleo-F303K8
00019 #define D_SCL                  PB_6 // specific for Nucleo-F303K8
00020 I2C hdc_i2c(D_SDA, D_SCL);
00021 #include "hdc1080.h"
00022 
00023 // Host PC Communication channels
00024 Serial pc(USBTX, USBRX); // tx, rx
00025 DigitalOut myled(LED1);
00026 
00027 int main()
00028 {
00029     pc.baud(9600);
00030     while(1) {
00031         printf("\r\\nHDC1080 Test\r\n");
00032         myled = !myled;
00033         hdc_begin();
00034         uint16_t manId = hdc_readManufactId();
00035         float tempC = hdc_readTemp();     
00036         float humid = hdc_readHumid();  
00037         unsigned long  serNum = hdc_readSerial();
00038         printf("manId=x%x, tempC=%0.3f humid=%0.3f serfNum=%ld\r\n",
00039           manId, tempC, humid, serNum);
00040         wait(3.0f);
00041     }
00042 }
00043 **/
00044 
00045 
00046 
00047 #ifndef hdc1080_h
00048 #define hdc1080_h
00049 #include "mbed.h"
00050 
00051 #define hdc_chip_addr (0x40 << 1) // Page #8.5.1.1 - 1000000
00052 // left shift 1 bit for 7 bit address required by
00053 // I2C library
00054 //#define hdc_chip_addr 0x40 // Page #8.5.1.1 - 1000000
00055 const int hdc_off_temp  = 0x00;
00056 const int hdc_off_humid = 0x01;
00057 const int hdc_off_config = 0x02;
00058 const int hdc_off_man_id = 0xFE;
00059 const int hdc_off_serial_first = 0xFB;
00060 const int hdc_off_serial_mid = 0xFC;
00061 const int hdc_off_serial_last = 0xFD;
00062 char hdc_comm = hdc_off_man_id;
00063 const float hdc_chip_error = -255;
00064 const unsigned long hdc_chip_err_l = 0;
00065 char hdc_buff[5];
00066 
00067 void hdc_begin()
00068 {
00069     //printf("hdc_begin\r\n");
00070     memset(hdc_buff,0,3);
00071     hdc_buff[0] = hdc_off_config;
00072     int res = hdc_i2c.write(hdc_chip_addr, hdc_buff, 2);
00073     #ifdef DEBUG3
00074     printf("hdc_begin write res=%d\r\n", res);
00075     #endif
00076 }
00077 
00078 uint16_t hdc_readData16(int chip_addr, int offset)
00079 {
00080     memset(hdc_buff,0,3);
00081     // send chip address onto buss
00082     hdc_buff[0] = offset;
00083     int res = hdc_i2c.write(chip_addr, hdc_buff, 1);
00084     if (res != 0) {
00085         #ifdef DEBUG3
00086         printf("error talking to chip %d offst=%d\r\n", chip_addr, offset);
00087         #endif
00088         return 0;
00089     }
00090     // read data from chip
00091     wait(0.015);
00092     memset(hdc_buff,0,3);
00093     res = hdc_i2c.read(hdc_chip_addr, hdc_buff,2);
00094     if (res != 0) {
00095         #ifdef DEBUG3
00096         printf("error reading chip %d offst=%d\r\n", chip_addr, offset);
00097         #endif
00098         return 0;
00099     }
00100     return  hdc_buff[0] << 8 | hdc_buff[1];
00101 }
00102 
00103 /* Read temperature from hdc_1080 chip.  Returns float
00104 containing the Celcius temperature or hdc_chip_error if
00105 error occurs reading the sensor */
00106 float hdc_readTemp()
00107 {
00108     uint16_t  rawT = hdc_readData16(hdc_chip_addr, hdc_off_temp);
00109     if (rawT == 0) {
00110         #ifdef DEBUG3
00111         printf("error reading hdc chip temp\r\n");
00112         #endif
00113         return hdc_chip_error;
00114     } else {
00115         float temp = ((float) rawT / pow(2.0f, 16.0f)) * 165.0f - 40.0f;
00116         #ifdef DEBUG3
00117         printf("temp=%0.3f\r\n", temp);
00118         #endif
00119         return temp;
00120     }
00121 }
00122 
00123 /* Read humidity from hdc_1080 chip.  Returns a float
00124 containing the humidity or hdc_chip_error if error 
00125 occurs reading the sensor */
00126 float hdc_readHumid()
00127 {
00128     uint16_t  rawH = hdc_readData16(hdc_chip_addr, hdc_off_humid);
00129     if (rawH == 0) {
00130         #ifdef DEBUG3
00131         printf("error reading hdc chip humid\r\n");
00132         #endif
00133         return hdc_chip_error;
00134     } else {
00135         float humid = ((float) rawH / pow(2.0f, 16.0f)) * 100.0f;
00136         #ifdef DEBUG3
00137         printf("humid humid=%0.3f\r\n", humid);
00138         #endif
00139         return humid;
00140     }
00141 }
00142 
00143 int hdc_readManufactId()
00144 {   
00145     uint16_t  rawid = hdc_readData16(hdc_chip_addr, hdc_off_man_id);
00146     if (rawid == 0) {
00147         #ifdef DEBUG3
00148         printf("error reading hdc chip manId\r\n");
00149         #endif
00150         return (int) hdc_chip_error;
00151     } else {  
00152         #ifdef DEBUG3      
00153         printf("man id=%x\r\n", (int) rawid);
00154         #endif
00155         return rawid;
00156     }    
00157 }
00158 
00159 unsigned long hdc_readSerial()
00160 {    
00161     wait(0.015);
00162     memset(hdc_buff,0,4);
00163     hdc_buff[0] = hdc_off_man_id;
00164     int res = hdc_i2c.write(hdc_chip_addr, hdc_buff, 1);
00165     if (res != 0) {      
00166       #ifdef DEBUG3
00167       printf("Error writing chip addr res=%d\r\n", res);
00168       #endif
00169       return (unsigned long) hdc_chip_err_l;
00170     }      
00171 
00172     wait(0.015);
00173     memset(hdc_buff,0,4);
00174     res = hdc_i2c.read(hdc_chip_addr, hdc_buff,4);
00175     if (res != 0) {
00176       #ifdef DEBUG3
00177       printf("Errot reading chip serial res=%d#\r\n", res);
00178       #endif
00179       return (unsigned long) hdc_chip_err_l;
00180     }
00181       
00182     unsigned long rawser = hdc_buff[0] << 16 | hdc_buff[1] << 8 | hdc_buff[0];
00183     #ifdef DEBUG3
00184     printf("ser=%lu\r\n", rawser);
00185     #endif
00186     return rawser;
00187 }
00188 
00189 #endif