http://odroid.com/dokuwiki/doku.php?id=en:odroidoduinoone
DHT11 Sensor (Humidity / Temperature sensor)
http://www.micro4you.com/files/sensor/DHT11.pdf
Connections are (V)oltage, (S)ignal, (G)round
DHT11
<package>
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VS G
For project hooked to digital pin 3 on Arduino Uno
Download dht.cpp and dht.h from below link and copy them into “~/sketchbook/libraries/dht”.
http://playground.arduino.cc/Main/DHTLib
#include <LiquidCrystal.h>
#include <dht.h>
/*******************************************************
This program will test the LCD panel, the buttons
and the Humidity/Temperature sensor
Version : 0.1
Date : 20-Oct-2013
By Hardkernel
********************************************************/
// for Digital Humidity and Temperature sensor (DHT11)
dht DHT;
#define DHT11_PIN 3
// Global variables
unsigned long elapsed_time;
// select the pins used on the LCD panel
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);
// define some values used by the panel and buttons
int lcd_key = 0;
int adc_key_in = 0;
#define btnRIGHT 0
#define btnUP 1
#define btnDOWN 2
#define btnLEFT 3
#define btnSELECT 4
#define btnNONE 5
// read the buttons
int read_LCD_buttons()
{
adc_key_in = analogRead(0); // read the value from the sensor
// my buttons when read are centered at these valies: 0, 144, 329, 504, 741
// we add approx 50 to those values and check to see if we are close
if (adc_key_in > 1000) return btnNONE; // We make this the 1st option for speed reasons since it will be the most likely result
if (adc_key_in < 50) return btnRIGHT;
if (adc_key_in < 195) return btnUP;
if (adc_key_in < 380) return btnDOWN;
if (adc_key_in < 555) return btnLEFT;
if (adc_key_in < 790) return btnSELECT;
return btnNONE; // when all others fail, return this...
}
void setup()
{
// initialize serial communication at 115200 bits per second:
Serial.begin(115200);
lcd.begin(16, 2); // start the LCD library
lcd.setCursor(0,0);
lcd.print(" Hello, ODUINO! "); // print a simple message
// 1234567890123456
delay(1500); // Splash for 1.5 second
Serial.println("ODUINO TEST PROGRAM ");
Serial.println();
Serial.println("Type,\tstatus,\tHumidity (%),\tTemperature (C)");
elapsed_time = millis()/1000; // Returns the number of milliseconds since the Arduino board began running the current program.
}
void loop()
{
lcd.setCursor(0,1); // move to the begining of the second line
lcd.print("KEY :");
lcd.setCursor(6,1); // move to the begining of the second line
lcd_key = read_LCD_buttons(); // read the buttons
switch (lcd_key) // depending on which button was pushed, we perform an action
{
case btnRIGHT:
{
lcd.print("RIGHT ");
Serial.println("RIGHT ");
break;
}
case btnLEFT:
{
lcd.print("LEFT ");
Serial.println("LEFT ");
break;
}
case btnUP:
{
lcd.print("UP ");
Serial.println("UP ");
break;
}
case btnDOWN:
{
lcd.print("DOWN ");
Serial.println("DOWN ");
break;
}
case btnSELECT:
{
lcd.print("SELECT");
Serial.println("SELECT ");
break;
}
case btnNONE:
{
lcd.print("NONE ");
break;
}
}
// Read & Display the humidity / temperature data every 1 second (approx.)
if(elapsed_time != millis()/1000)
{
elapsed_time = millis()/1000;
Serial.print("DHT11, \t");
int chk = DHT.read11(DHT11_PIN);
switch (chk)
{
case DHTLIB_OK:
Serial.print("OK,\t");
break;
case DHTLIB_ERROR_CHECKSUM:
Serial.print("Checksum error,\t");
break;
case DHTLIB_ERROR_TIMEOUT:
Serial.print("Time out error,\t");
break;
default:
Serial.print("Unknown error,\t");
break;
}
// DISPLAY DATA
Serial.print(DHT.humidity,0);
Serial.print(",\t");
Serial.println(DHT.temperature,0);
lcd.setCursor(0,0); // move cursor to second line "1" and 9 spaces over
lcd.print("HUMI:");
lcd.print((int)(DHT.humidity));
lcd.print("%");
lcd.print(" TEM:");
lcd.print((int)(DHT.temperature));
lcd.print("C");
}
delay(50); // delay 50 msec.
}
