Hi,
I have just had some noobie success setting up a temperture sensor outputting to an LCD 
The example code requires a key press to refresh the reading.
Would anyone have a couple of mins to show how I might get the code to update the temperature display say every second (ie without a key press)? Also, is it possible to add degress (symbol)C after the reading on the dsiplay?
The kit I'm using is here: http://www.nuelectronics.com/estore/index.php?main_page=product_info&cPath=1&products_id=2
And the code is:
//example use of LCD4Bit_mod library
#include <LCD4Bit_mod.h>
#include <stdio.h>
#define TEMP_PIN 3
//create object to control an LCD.
//number of lines in display=1
LCD4Bit_mod lcd = LCD4Bit_mod(2);
void getCurrentTemp(char *temp);
//Key message
int adc_key_val[5] ={30, 150, 360, 535, 760 };
int NUM_KEYS = 5;
int adc_key_in;
int key=-1;
int oldkey=-1;
void setup() {
pinMode(13, OUTPUT); //we'll use the debug LED to output a heartbeat
// initialize DS18B20 datapin
digitalWrite(TEMP_PIN, LOW);
pinMode(TEMP_PIN, INPUT); // sets the digital pin as input (logic 1)
lcd.init();
//optionally, now set up our application-specific display settings, overriding whatever the lcd did in lcd.init()
//lcd.commandWrite(0x0F);//cursor on, display on, blink on. (nasty!)
lcd.clear();
lcd.printIn("Temperature is");
}
void loop() {
char temp_string[10];
adc_key_in = analogRead(0); // read the value from the sensor
key = get_key(adc_key_in); // convert into key press
if (key != oldkey) // if keypress is detected
{
delay(50); // wait for debounce time
adc_key_in = analogRead(0); // read the value from the sensor
key = get_key(adc_key_in); // convert into key press
if (key != oldkey)
{
oldkey = key;
getCurrentTemp(temp_string);
lcd.cursorTo(2, 0); //line=2, x=0
lcd.printIn(temp_string);
}
}
}
// Convert ADC value to key number
int get_key(unsigned int input)
{
int k;
for (k = 0; k < NUM_KEYS; k++)
{
if (input < adc_key_val[k])
{
return k;
}
}
if (k >= NUM_KEYS)
k = -1; // No valid key pressed
return k;
}
void OneWireReset(int Pin) // reset. Should improve to act as a presence pulse
{
digitalWrite(Pin, LOW);
pinMode(Pin, OUTPUT); // bring low for 500 us
delayMicroseconds(500);
pinMode(Pin, INPUT);
delayMicroseconds(500);
}
void OneWireOutByte(int Pin, byte d) // output byte d (least sig bit first).
{
byte n;
for(n=8; n!=0; n--)
{
if ((d & 0x01) == 1) // test least sig bit
{
digitalWrite(Pin, LOW);
pinMode(Pin, OUTPUT);
delayMicroseconds(5);
pinMode(Pin, INPUT);
delayMicroseconds(60);
}
else
{
digitalWrite(Pin, LOW);
pinMode(Pin, OUTPUT);
delayMicroseconds(60);
pinMode(Pin, INPUT);
}
d=d>>1; // now the next bit is in the least sig bit position.
}
}
byte OneWireInByte(int Pin) // read byte, least sig byte first
{
byte d, n, b;
for (n=0; n<8; n++)
{
digitalWrite(Pin, LOW);
pinMode(Pin, OUTPUT);
delayMicroseconds(5);
pinMode(Pin, INPUT);
delayMicroseconds(5);
b = digitalRead(Pin);
delayMicroseconds(50);
d = (d >> 1) | (b<<7); // shift d to right and insert b in most sig bit position
}
return(d);
}
void getCurrentTemp(char *temp)
{
int HighByte, LowByte, TReading, Tc_100, sign, whole, fract;
OneWireReset(TEMP_PIN);
OneWireOutByte(TEMP_PIN, 0xcc);
OneWireOutByte(TEMP_PIN, 0x44); // perform temperature conversion, strong pullup for one sec
OneWireReset(TEMP_PIN);
OneWireOutByte(TEMP_PIN, 0xcc);
OneWireOutByte(TEMP_PIN, 0xbe);
LowByte = OneWireInByte(TEMP_PIN);
HighByte = OneWireInByte(TEMP_PIN);
TReading = (HighByte << 8) + LowByte;
sign = TReading & 0x8000; // test most sig bit
if (sign) // negative
{
TReading = (TReading ^ 0xffff) + 1; // 2's comp
}
Tc_100 = (6 * TReading) + TReading / 4; // multiply by (100 * 0.0625) or 6.25
whole = Tc_100 / 100; // separate off the whole and fractional portions
fract = Tc_100 % 100;
/*
if(sign) temp[0]='-';
else temp[0]='+';
temp[1]= whole%100+'0';
temp[2]= (whole-100temp[1])%10 +'0' ;
temp[3]= whole-100temp[1]-10*temp[2] +'0';
temp[4]='.';
temp[5]=fract%10 +'0';
temp[6]=fract-temp[5]*10 +'0';
temp[7] = '\0';
*/
sprintf(temp, "%c%3d%c%2d", (sign==0)?'+':'-', whole, '.', fract);
}