/*
Multi Temp Sensor
Arduino | hardware-help
Wiring up multiple sensors (4 DHT22's etc) to 1 data pin using a register.

vito — 7/16/24 at 3:30 AM
I am attempting to use 74hc595 register to extend the number of 
available pins on the UNO board. The logic was to only have 1 sensor 
active at once and read them off all the same digital pin.

After building it, it doesn't work and from an oscilloscope,  I can 
see that the voltage drops to 5V to about 1V after connecting 2 DHTs 
to the register pins.
I can confirm that there is only one register output on at once  
however I guess the digital pins interact with each other when connect in parallel.
The images show the 2 signals at the digital pin when only 1 is connected vs 2. 

The circuit is basically Q0 and Q1 connected to the +Vcc on the DHT22 and the other wire grounded.

DS18B20 example from https://lastminuteengineers.com/multiple-ds18b20-arduino-tutorial/
*/

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

// Data wire is plugged into digital pin 2 on the Arduino
#define ONE_WIRE_BUS 2

// Setup a oneWire instance to communicate with any OneWire device
OneWire oneWire(ONE_WIRE_BUS);	

// Pass oneWire reference to DallasTemperature library
DallasTemperature sensors(&oneWire);

int deviceCount = 0;
float tempC;

void setup(void)
{
  sensors.begin();	// Start up the library
  Serial.begin(9600);
  
  // locate devices on the bus
  Serial.print("Locating devices...");
  Serial.print("Found ");
  deviceCount = sensors.getDeviceCount();
  Serial.print(deviceCount, DEC);
  Serial.println(" devices.");
  Serial.println("");
}

void loop(void)
{ 
  // Send command to all the sensors for temperature conversion
  sensors.requestTemperatures(); 
  
  // Display temperature from each sensor
  for (int i = 0;  i < deviceCount;  i++)
  {
    Serial.print("Sensor ");
    Serial.print(i+1);
    Serial.print(" : ");
    tempC = sensors.getTempCByIndex(i);
    Serial.print(tempC);
    Serial.print((char)176);//shows degrees character
    Serial.print("C  |  ");
    Serial.print(DallasTemperature::toFahrenheit(tempC));
    Serial.print((char)176);//shows degrees character
    Serial.println("F");
  }
  
  Serial.println("");
  delay(1000);
}