Caratteristiche:
2 sensori 1-wire (ds1820) in modalita' parassita.
1 74HC595 shift register per utilizzare solo 3 wire per pilotare un display lcd
1 lcd standard 16x2
Librerie:
Onewire: http://www.pjrc.com/teensy/td_libs_OneWire.html
ShiftOut: http://www.instructables.com/id/LCD-Shi ... r-Arduino/
Lcd: http://www.instructables.com/id/LCD-Shi ... r-Arduino/
Sketch:
Codice: Seleziona tutto
#include <OneWire.h>
#include <Lcd.h>
#include <ShiftOut.h>
// DS18S20 Temperature chip i/o
OneWire ds(10); // on pin 10
ShiftOut sOut(8, 12, 11, 1);
Lcd lcd = Lcd(16, FUNCTION_4BIT | FUNCTION_2LINE | FUNCTION_5x11, &sOut);
void setup()
{
// initialize inputs/outputs
// start serial port
Serial.begin(9600);
lcd.set_ctrl_pins(CTRLPINS(1,2,3)); // RS->1, RW->2, E->3
lcd.set_data_pins(_4PINS(4,5,6,7)); // D4->4, D5->5, D6->6, D7->7
lcd.setup();
lcd.clear();
}
void loop()
{
int HighByte, LowByte, TReading, SignBit, Tc_100, Whole, Fract;
byte i;
byte present = 0;
byte data[12];
byte addr[8];
if ( !ds.search(addr)) {
// Serial.print("No more addresses.\n\n");
Serial.println("------------------");
ds.reset_search();
delay(8000);
//lcd.home();
lcd.clear();
return;
}
// Serial.print("R=");
// for( i = 0; i < 8; i++) {
// Serial.print(addr[i], HEX);
// Serial.print(" ");
// }
if ( OneWire::crc8( addr, 7) != addr[7]) {
Serial.print("CRC is not valid!\n");
return;
}
if ( addr[0] == 0x10) {
Serial.print("Device is a DS18S20 family device.");
}
else if ( addr[0] == 0x28) {
Serial.print("Device is a DS18B20 family device.");
}
else {
Serial.print("Device family is not recognized: 0x");
Serial.println(addr[0],HEX);
return;
}
ds.reset();
ds.select(addr);
ds.write(0x44,1); // start conversion, with parasite power on at the end
delay(1000); // maybe 750ms is enough, maybe not
// we might do a ds.depower() here, but the reset will take care of it.
present = ds.reset();
ds.select(addr);
ds.write(0xBE); // Read Scratchpad
// Serial.print("P=");
// Serial.print(present,HEX);
// Serial.print(" ");
for ( i = 0; i < 9; i++) { // we need 9 bytes
data[i] = ds.read();
// Serial.print(data[i], HEX);
// Serial.print(" ");
}
// Serial.print(" CRC=");
// Serial.print( OneWire::crc8( data, 8), HEX);
Serial.println();
//lcd.clear();
LowByte = data[0];
HighByte = data[1];
TReading = (HighByte << 8) + LowByte;
SignBit = TReading & 0x8000; // test most sig bit
if (SignBit) // 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;
Serial.print("Temperatura: ");
lcd.print("Temp.: ");
if (SignBit) // If its negative
{
Serial.print("-");
lcd.print("-");
}
Serial.print(Whole);
lcd.print(Whole);
Serial.print(".");
lcd.print(".");
if (Fract < 10)
{
Serial.print("0");
lcd.print("0");
}
Serial.print(Fract);
lcd.print(Fract);
Serial.println();
lcd.move_to(1,2);
//lcd.home();
//lcd.print((long)millis() / 1000);
}
La resistenza volante di pullup serve per l'alimentazione parassita dei DS1820 (fili rosso e nero volanti).
Temperatura esterna e interna (azz che freddo)
Notare anche il trimmer per la regolazione del contrasto.
saluti
ragno