Digital Temperature Sensor + Module Display

Using Arduino Sensors
#1

I merge two codes, display module and temperature sensor, but it gives error in the temperature reading.

#include <OneWire.h>
#include <TM74HC595Display.h>
#include <TimerOne.h> 

int DS18S20_Pin = 2; //DS18S20 Signal pin on digital 2
int SCLK = 7;
int RCLK = 6;
int DIO = 5;

TM74HC595Display disp(SCLK, RCLK, DIO);

//Temperature chip i/o
OneWire ds(DS18S20_Pin); // on digital pin 2

void setup(void) {

 Timer1.initialize(1500); // set a timer of length 1500
 Timer1.attachInterrupt(timerIsr); // attach the service routine here
Serial.begin(9600);
}

void loop(void) {
float temperature = getTemp(); //will take about 750ms to run
Serial.println(temperature);
disp.dispFloat(temperature, 2); //send float indicators
delay(10000);
//disp.clear();   //clear display
}


float getTemp(){
//returns the temperature from one DS18S20 in DEG Celsius

byte data[12];
byte addr[8];

if ( !ds.search(addr)) {
//no more sensors on chain, reset search
ds.reset_search();
return -1000;
}

if ( OneWire::crc8( addr, 7) != addr[7]) {
Serial.println("CRC is not valid!");
return -1000;
}

if ( addr[0] != 0x10 && addr[0] != 0x28) {
Serial.print("Device is not recognized");
return -1000;
}

ds.reset();
ds.select(addr);
ds.write(0x44,1); // start conversion, with parasite power on at the end

delay(750); // Wait for temperature conversion to complete

byte present = ds.reset();
ds.select(addr); 
ds.write(0xBE); // Read Scratchpad


for (int i = 0; i < 9; i++) { // we need 9 bytes
data[i] = ds.read();
}

ds.reset_search();

byte MSB = data[1];
byte LSB = data[0];

float tempRead = ((MSB << 8) | LSB); //using two's compliment
float TemperatureSum = tempRead / 16;

return TemperatureSum;

}
void timerIsr()
{
  disp.timerIsr();
}
#2

Post the error message.

#3

Did you try the temp sensor on it’s own first (before merging).
Try this sketch.
Leo…

// DS18B20 with 4k7 resistor between +5volt and ouput, connected to pin D6

#include <DallasTemperature.h>
#include <OneWire.h>

OneWire oneWire(6); // pin D6
DallasTemperature sensors(&oneWire);
float temp;

void setup() {
  Serial.begin(115200);
  Serial.println("DS18B20 thermometer");
  sensors.begin();
}

void loop() {
  sensors.requestTemperatures();
  temp = sensors.getTempCByIndex(0);
  Serial.print("Temp is ");
  Serial.print(temp, 4);
  Serial.println(" C");
}
#4

Error is -> Returns temperature -1000

#5

The code works with some settings, especially in the value “Timer1.initialize”, thanks!

#include <DallasTemperature.h>
#include <OneWire.h>
#include <TM74HC595Display.h>
#include <TimerOne.h>

OneWire oneWire(2); // pin D2
DallasTemperature sensors(&oneWire);
float temp;
int SCLK = 7;
int RCLK = 6;
int DIO = 5;
TM74HC595Display disp(SCLK, RCLK, DIO);

void setup() {
  Serial.begin(9600);
  Serial.println("DS18B20 thermometer");
  sensors.begin();
  Timer1.initialize(1000000); // set a timer of length 
  Timer1.attachInterrupt(timerIsr); // attach the service routine here
}

void loop() {
  sensors.requestTemperatures();
  temp = sensors.getTempCByIndex(0);
  Serial.print("Temp is ");
  Serial.print(temp, 4);
  Serial.println(" C");
  disp.dispFloat(temp, 2); //send float indicators
  delay(1000);
  disp.clear();   //clear display
}
void timerIsr()
{
  disp.timerIsr();
}
#6

Not sure which Arduino you're using, and what the libraries exactly do.
I might be wrong, but I would stay away from pin D2 and D3 (interrupt pins on an Uno).
Leo..

#7

Use the library DallasTemperature.h. It will make the code alot simpiler and easier to use

#8