![](/media/cache/img/default_profile.jpg.50x50_q85.jpg)
DHT testprogram
Revision 0:9ef709bfeb08, committed 2012-07-10
- Comitter:
- Wimpie
- Date:
- Tue Jul 10 13:11:23 2012 +0000
- Commit message:
Changed in this revision
diff -r 000000000000 -r 9ef709bfeb08 DHT/DHT.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/DHT/DHT.cpp Tue Jul 10 13:11:23 2012 +0000 @@ -0,0 +1,233 @@ +/* + * DHT Library for Digital-output Humidity and Temperature sensors + * + * Works with DHT11, DHT22 + * SEN11301P, Grove - Temperature&Humidity Sensor (Seeed Studio) + * SEN51035P, Grove - Temperature&Humidity Sensor Pro (Seeed Studio) + * AM2302 , temperature-humidity sensor + * HM2303 , Digital-output humidity and temperature sensor + * + * Copyright (C) Wim De Roeve + * based on DHT22 sensor library by HO WING KIT + * Arduino DHT11 library + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documnetation 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 + * furished 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 OR 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 "DHT.h" + +#define DHT_DATA_BIT_COUNT 41 + +DHT::DHT(PinName pin,int DHTtype) { + _pin = pin; + _DHTtype = DHTtype; + _firsttime=true; +} + +DHT::~DHT() { +} + +int DHT::readData() { + int i, j, retryCount,b; + unsigned int bitTimes[DHT_DATA_BIT_COUNT]; + + eError err = ERROR_NONE; + time_t currentTime = time(NULL); + + DigitalInOut DHT_io(_pin); + + for (i = 0; i < DHT_DATA_BIT_COUNT; i++) { + bitTimes[i] = 0; + } + + if (!_firsttime) { + if (int(currentTime - _lastReadTime) < 2) { + err = ERROR_NO_PATIENCE; + return err; + } + } else { + _firsttime=false; + _lastReadTime=currentTime; + } + retryCount = 0; + + do { + if (retryCount > 125) { + err = BUS_BUSY; + return err; + } + retryCount ++; + wait_us(2); + } while ((DHT_io==0)); + + + DHT_io.output(); + DHT_io = 0; + wait_ms(18); + DHT_io = 1; + wait_us(40); + DHT_io.input(); + + retryCount = 0; + do { + if (retryCount > 40) { + err = ERROR_NOT_PRESENT; + return err; + } + retryCount++; + wait_us(1); + } while ((DHT_io==1)); + + if (err != ERROR_NONE) { + return err; + } + + wait_us(80); + + for (i = 0; i < 5; i++) { + for (j = 0; j < 8; j++) { + + retryCount = 0; + do { + if (retryCount > 75) { + err = ERROR_DATA_TIMEOUT; + return err; + } + retryCount++; + wait_us(1); + } while (DHT_io == 0); + wait_us(40); + bitTimes[i*8+j]=DHT_io; + + int count = 0; + while (DHT_io == 1 && count < 100) { + wait_us(1); + count++; + } + } + } + DHT_io.output(); + DHT_io = 1; + for (i = 0; i < 5; i++) { + b=0; + for (j=0; j<8; j++) { + if (bitTimes[i*8+j+1] > 0) { + b |= ( 1 << (7-j)); + } + } + DHT_data[i]=b; + } + + if (DHT_data[4] == ((DHT_data[0] + DHT_data[1] + DHT_data[2] + DHT_data[3]) & 0xFF)) { + _lastReadTime = currentTime; + _lastTemperature=CalcTemperature(); + _lastHumidity=CalcHumidity(); + + } else { + err = ERROR_CHECKSUM; + } + + return err; + +} + +float DHT::CalcTemperature() { + int v; + + switch (_DHTtype) { + case DHT11: + v = DHT_data[2]; + return float(v); + case DHT22: + v = DHT_data[2] & 0x7F; + v *= 256; + v += DHT_data[3]; + v /= 10; + if (DHT_data[2] & 0x80) + v *= -1; + return float(v); + } + return 0; +} + +float DHT::ReadHumidity() { + return _lastHumidity; +} + +float DHT::ConvertCelciustoFarenheit(float celsius) { + return celsius * 9 / 5 + 32; +} + +float DHT::ConvertCelciustoKelvin(float celsius) { + return celsius + 273.15; +} + +// dewPoint function NOAA +// reference: http://wahiduddin.net/calc/density_algorithms.htm +float DHT::CalcdewPoint(float celsius, float humidity) { + float A0= 373.15/(273.15 + celsius); + float SUM = -7.90298 * (A0-1); + SUM += 5.02808 * log10(A0); + SUM += -1.3816e-7 * (pow(10, (11.344*(1-1/A0)))-1) ; + SUM += 8.1328e-3 * (pow(10,(-3.49149*(A0-1)))-1) ; + SUM += log10(1013.246); + float VP = pow(10, SUM-3) * humidity; + float T = log(VP/0.61078); // temp var + return (241.88 * T) / (17.558-T); +} + +// delta max = 0.6544 wrt dewPoint() +// 5x faster than dewPoint() +// reference: http://en.wikipedia.org/wiki/Dew_point +float DHT::CalcdewPointFast(float celsius, float humidity) +{ + float a = 17.271; + float b = 237.7; + float temp = (a * celsius) / (b + celsius) + log(humidity/100); + float Td = (b * temp) / (a - temp); + return Td; +} + +float DHT::ReadTemperature(eScale Scale) { + if (Scale == FARENHEIT) + return ConvertCelciustoFarenheit(_lastTemperature); + else if (Scale == KELVIN) + return ConvertCelciustoKelvin(_lastTemperature); + else + return _lastTemperature; +} + +float DHT::CalcHumidity() { + int v; + + switch (_DHTtype) { + case DHT11: + v = DHT_data[0]; + return float(v); + case DHT22: + v = DHT_data[0]; + v *= 256; + v += DHT_data[1]; + v /= 10; + return float(v); + } + return 0; +} + +
diff -r 000000000000 -r 9ef709bfeb08 DHT/DHT.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/DHT/DHT.h Tue Jul 10 13:11:23 2012 +0000 @@ -0,0 +1,94 @@ +/* + * DHT Library for Digital-output Humidity and Temperature sensors + * + * Works with DHT11, DHT21, DHT22 + * SEN11301P, Grove - Temperature&Humidity Sensor (Seeed Studio) + * SEN51035P, Grove - Temperature&Humidity Sensor Pro (Seeed Studio) + * AM2302 , temperature-humidity sensor + * RHT01,RHT02, RHT03 , Humidity and Temperature Sensor (Sparkfun) + * + * Copyright (C) Wim De Roeve + * based on DHT22 sensor library by HO WING KIT + * Arduino DHT11 library + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documnetation 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 + * furished 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 OR 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. + */ + +#ifndef MBED_DHT_H +#define MBED_DHT_H + +#include "mbed.h" + +enum eType{ + DHT11 = 11, + SEN11301P = 11, + RHT01 = 11, + DHT22 = 22, + AM2302 = 22, + SEN51035P = 22, + RHT02 = 22, + RHT03 = 22 + } ; + +enum eError { + ERROR_NONE = 0, + BUS_BUSY =1, + ERROR_NOT_PRESENT =2 , + ERROR_ACK_TOO_LONG =3 , + ERROR_SYNC_TIMEOUT = 4, + ERROR_DATA_TIMEOUT =5 , + ERROR_CHECKSUM = 6, + ERROR_NO_PATIENCE =7 +} ; + +typedef enum { + CELCIUS =0 , + FARENHEIT =1, + KELVIN=2 +} eScale; + + +class DHT { + +public: + + DHT(PinName pin,int DHTtype); + ~DHT(); + int readData(void); + float ReadHumidity(void); + float ReadTemperature(eScale Scale); + float CalcdewPoint(float celsius, float humidity); + float CalcdewPointFast(float celsius, float humidity); + +private: + time_t _lastReadTime; + float _lastTemperature; + float _lastHumidity; + PinName _pin; + bool _firsttime; + int _DHTtype; + int DHT_data[6]; + float CalcTemperature(); + float CalcHumidity(); + float ConvertCelciustoFarenheit(float); + float ConvertCelciustoKelvin(float); + +}; + +#endif
diff -r 000000000000 -r 9ef709bfeb08 Debug/DebugTrace.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Debug/DebugTrace.cpp Tue Jul 10 13:11:23 2012 +0000 @@ -0,0 +1,138 @@ +/* +* DebugTrace. Allows dumping debug messages/values to serial or +* to file. +* +* Copyright (C) <2009> Petras Saduikis <petras@petras.co.uk> +* +* This file is part of DebugTrace. +* +* DebugTrace is free software: you can redistribute it and/or modify +* it under the terms of the GNU General Public License as published by +* the Free Software Foundation, either version 3 of the License, or +* (at your option) any later version. +* +* DebugTrace is distributed in the hope that it will be useful, +* but WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +* GNU General Public License for more details. +* +* You should have received a copy of the GNU General Public License +* along with DebugTrace. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "DebugTrace.h" +#include <mbed.h> +#include <stdarg.h> +//#include <string.h> + +Serial logSerial(USBTX, USBRX); +//LocalFileSystem local("local"); + +//const char* FILE_PATH = "/sd/"; +//const char* EXTN = ".bak"; + +DebugTrace::DebugTrace(eLog on, eLogTarget mode)://, const char* fileName, int maxSize) : + enabled(on), logMode(mode) { //, maxFileSize(maxSize), currentFileSize(0), logFileStatus(0) + /* + // allocate memory for file name strings + int str_size = (strlen(fileName) + strlen(FILE_PATH) + strlen(EXTN) + 1) * sizeof(char); + logFile = (char*)malloc(str_size); + logFileBackup = (char*)malloc(str_size); + + // add path to log file name + strcpy(logFile, FILE_PATH); + strcat(logFile, fileName); + + // create backup file name + strcpy(logFileBackup, logFile); + strcpy(logFileBackup, strtok(logFileBackup, ".")); + strcat(logFileBackup, EXTN);*/ + // logSerial.baud(115200); +} + + +DebugTrace::~DebugTrace() { + // dust to dust, ashes to ashes + /*if (logFile != NULL) free(logFile); + if (logFileBackup != NULL) free(logFileBackup);*/ +} + +void DebugTrace::clear() { + // don't care about whether these fail + /*remove(logFile); + remove(logFileBackup);*/ +} + +void DebugTrace::backupLog() { + // delete previous backup file + /*if (remove(logFileBackup)) + { + // standard copy stuff + char ch; + FILE* to = fopen(logFileBackup, "wb"); + if (NULL != to) + { + FILE* from = fopen(logFile, "rb"); + if (NULL != from) + { + while(!feof(from)) + { + ch = fgetc(from); + if (ferror(from)) break; + + if(!feof(from)) fputc(ch, to); + if (ferror(to)) break; + } + } + + if (NULL != from) fclose(from); + if (NULL != to) fclose(to); + } + } + + // now delete the log file, so we are ready to start again + // even if backup creation failed - the show must go on! + logFileStatus = remove(logFile);*/ +} + +void DebugTrace::traceOut(const char* fmt, ...) { + if (enabled) { + va_list ap; // argument list pointer + va_start(ap, fmt); + + if (TO_SERIAL == logMode) { + vfprintf(logSerial, fmt, ap); + + } else { // TO_FILE + /*vfprintf(logSerial, fmt, ap); + if (0 == logFileStatus) // otherwise we failed to remove a full log file + { + // Write data to file. Note the file size may go over limit + // as we check total size afterwards, using the size written to file. + // This is not a big issue, as this mechanism is only here + // to stop the file growing unchecked. Just remember log file sizes may + // be some what over (as apposed to some what under), so don't push it + // with the max file size. + FILE* fp = fopen(logFile, "a"); + if (NULL == fp) + { + va_end(ap); + return; + } + int size_written = vfprintf(fp, fmt, ap); + fclose(fp); + + // check if we are over the max file size + // if so backup file and start again + currentFileSize += size_written; + if (currentFileSize >= maxFileSize) + { + backupLog(); + currentFileSize = 0; + } + }*/ + } + + va_end(ap); + } +}
diff -r 000000000000 -r 9ef709bfeb08 Debug/DebugTrace.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Debug/DebugTrace.h Tue Jul 10 13:11:23 2012 +0000 @@ -0,0 +1,51 @@ +/* +* DebugTrace. Allows dumping debug messages/values to serial or +* to file. +* +* Copyright (C) <2009> Petras Saduikis <petras@petras.co.uk> +* +* This file is part of DebugTrace. +* +* DebugTrace is free software: you can redistribute it and/or modify +* it under the terms of the GNU General Public License as published by +* the Free Software Foundation, either version 3 of the License, or +* (at your option) any later version. +* +* DebugTrace is distributed in the hope that it will be useful, +* but WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +* GNU General Public License for more details. +* +* You should have received a copy of the GNU General Public License +* along with DebugTrace. If not, see <http://www.gnu.org/licenses/>. +*/ + +#ifndef SNATCH59_DEBUGTRACE_H +#define SNATCH59_DEBUGTRACE_H + +enum eLog {OFF, ON}; +enum eLogTarget {TO_SERIAL, TO_FILE}; + +class DebugTrace +{ +public: + + DebugTrace(eLog on, eLogTarget mode);//, const char* fileName = "debuglog.txt", const int maxSize = 4194304); + ~DebugTrace(); + // char message[80]; + void clear(); + void traceOut(const char* fmt, ...); + +private: + eLog enabled; + eLogTarget logMode; + /* int maxFileSize; + int currentFileSize; + char* logFile; + char* logFileBackup; + int logFileStatus; // if things go wrong, don't write any more data to file*/ + + void backupLog(); +}; + +#endif
diff -r 000000000000 -r 9ef709bfeb08 main.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Tue Jul 10 13:11:23 2012 +0000 @@ -0,0 +1,28 @@ +#include "mbed.h" +#include "DHT.h" + +DigitalOut myled(LED1); + +DHT sensor(p23,SEN11301P); // Use the SEN11301P sensor + +int main() { + int err; + printf("\r\nDHT Test program"); + printf("\r\n******************\r\n"); + wait(1); // wait 1 second for device stable status + while (1) { + myled = 1; + err = sensor.readData(); + if (err == 0) { + printf("Temperature is %4.2f C \r\n",sensor.ReadTemperature(CELCIUS)); + printf("Temperature is %4.2f F \r\n",sensor.ReadTemperature(FARENHEIT)); + printf("Temperature is %4.2f K \r\n",sensor.ReadTemperature(KELVIN)); + printf("Humidity is %4.2f \r\n",sensor.ReadHumidity()); + printf("Dew point is %4.2f \r\n",sensor.CalcdewPoint(sensor.ReadTemperature(CELCIUS), sensor.ReadHumidity())); + printf("Dew point (fast) is %4.2f \r\n",sensor.CalcdewPointFast(sensor.ReadTemperature(CELCIUS), sensor.ReadHumidity())); + } else + printf("\r\nErr %i \n",err); + myled = 0; + wait(5); + } +} \ No newline at end of file
diff -r 000000000000 -r 9ef709bfeb08 mbed.bld --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Tue Jul 10 13:11:23 2012 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/737756e0b479