Long Distance Industrial IoT with Dallas Digital Thermometer DS18B20 with
Arduino UNO coupled to NRF radio for transmission of data to the other end at 1 Km distance
Main Features of the DS18B20 temperature sensor:
- It comes with factory embedded 64 bit address.
- It is a 1-wire digital temperature sensor with built in SoC (System on Chip).
- It comes with a sealed package that lets precisely measure temperatures with 12bit ADC with accuracy of ±0.5°C
- A DS18B20 is factory calibrated to output the right temperature.
- It is weather proof IP66 rated so it can be immersed in water or any liquid to measure temperature.
- It communicates on a common bus and several devices can be connected in parallel.
- The Sensor can measure the temperature between -55 to 125°C (-67°F to +257°F). The cable is jacketed in PVC.
- DS18B20 is a digital temperature sensor, so input doesn’t affect the output reading.
- DS18B20 is a digital sensor, there is no effect in any output value.
- each one has a unique 64-bit ID burned in at the factory to differentiate them.
- The sensor works from 3.0 to 5.0V,
- The high air data rate combined with two power saving modes makes the nRF24L01 module very suitable for ultra low power designs. The power consumption of this module is just around 12 milliamps during transmission (TX) which is even lower than a single led.
- Operating voltage is between 1.9V to 3.6V. All other pins on this board are 5V tolerant making it easy to connect to an Arduino without using a logic level converter. It has an integrated (on chip) voltage regulator
- The Range of this module as per its datasheet is 100m but it works up to 50 to 60 meters in real world conditions.
- The module has 125 independent RF channels giving the possibility to have a network of "125 independently working modems" in one place.
- Each channel can have up to "6 addresses or 6 data pipes" or in other words, each unit can communicate with up to 6 other units at the same time (1:6 star networks).
- The module is configured and operated through a Serial Peripheral Interface (SPI).
The sensor has 3 wires:
Black: GND
Red: VCC
Yellow: 1-Wire Data
In order to use the DS18B20 properly, two libraries will be necessary:
OneWire
DallasTemperature
Install both libraries in your Arduino IDE Library depository.
The frequency to read data: 1 second
How to build an Arduino wireless network, composed of multiple NRF24L01 transceiver modules: Let us first look at the advantages NRF24L:
– The module operates at a frequency of 2.4GHz, which is one of the ISM band which means it is open to use in most of the countries around the World.
– Data transfer rate is between 250kbps to 2Mbps baud.
– This module is designed for ultra low power wireless applications. It has 2 power saving modes operating at 22uA Standby-I mode and 900nA in power down mode – which makes these modules suitable for battery operated nodes.
