Arduino nano with MAX485 and DS18B20

[burimp]

Hi, i have three postions where i want to measure temperature with arduino nano with MAX485 and DS18B20 but i need some help with the software pls help!

[sterretje]

Which part of the software?

Reading the DS18B20?
Transferring the data?
Where must the measured data go to? Other Arduino? PC? ...?

[ruilviana]

1. " https://www.instructables.com/Arduino-Nano-and-Two-DS18B20-Temperature-Sensors-W/

2. https://www.instructables.com/RS485-Serial-Communication-Between-Arduino-Mega-an/

The web is full of examples. Just look for it.

[burimp]

@burimp

reading data from ds18b20 and sendin to a pc

reading data from ds18b20 and sendin to a pc

[GolamMostafa]

You may get familiar with the following facts of DS18B20 Digital Temp Sensor and then create your sketch:

1. More than one sensors can be connected with an input pin of the Arduino UNO; hence, it is a "One Wire Device".

2. The following lines are included in the sketch to tell that the sensor is connected with DPin-7. The Library named OneWire.h contains C++ codes for the methods that are applied on the object ds.

#include<OneWire.h>
OneWire ds(7);

3. Every sensor has its own 64-bit (8-byte) identification codes called ROM Code which is engraved in the ROM memory of the sensor at manufacturing time. The following lines/codes acquire the ROM Code and is saved in an array.

byte romCode[8];   
ds.reset();
ds.search(romCode);

4. The sensor can register a change of 0.0625⁰C of temperature.

5. The temperature sensing element of the sensor produces DC voltage proportional to the surrounding temperature. Execution of the following codes begins the analog-to-digital conversion proocess. The conversion takes about 750 ms time (maximum). After conversion, the 12-bit temperature value is stored within the upper two byte locations of the following 9-byte wide buffer known as Scratch Pad Memory (Fig-1).

ds.reset();
ds.select(romCode);
ds.write(0x44);
delay(750);

Figure-1:

6. The positional weights for the bits of the "Temp Signal" locations are given below (Fig-2). The Fig-2 has also explained the mechanism of computing temperature signal from the bits distributed over two 8-bit wide locations.

Figure-2:

7. Execution of the following codes brings/acquires the content of the buffer from the sensor and save it in an array.

byte myData[9];
ds.reset();
ds.select(romCode);
ds.write(0xBE);
ds.read_bytes(myData);

8. Connect the data/signal pin of your sensor with DPin-7 of UNO and connect a 4.7k pull-up resistor between DPin-7 and 5V/VCC. Do not forget to connect the VCC-pin and GND-pin of the sensor with 5V-pin and GND-pin of Arduino UNO.

9. Open IDE with the following two blank functions and insert the codes mentioned above at the appropriate places. Study/follow Fig-2 to compute the float type temperature value and show it on the Serial Monitor (at 1-sec interval) that comes on the desktop of the PC.

void setup()
{

}

void loop()
{

}