ESP8266 NodeMCU Interface DSB1820

Real-World Use

Where this is useful?

• Monitoring room or industrial temperature.
• IoT projects (send temperature to cloud like MQTT, Blynk, or ThingSpeak).
• Smart home automation (AC/fan control).
• Data logging for greenhouse or aquarium.

Code of ESP8266 NodeMCU Interface DSB1820

local ow_pin = 1 -- gpio-02
ds18b20.setup(ow_pin)

ds18b20.read(
    function(ind,rom,res,temp,tdec,par)
        print(ind,
            string.format("%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X",
                string.match(rom,"(%d+):(%d+):(%d+):(%d+):(%d+):(%d+):(%d+):(%d+)")
            ),
            res,temp,tdec,par
        )
        print("Temp : "..temp)
    end,{});

 

Explanation

• ow_pin = 1: Here you assign NodeMCU pin D1 (which maps to GPIO2) as the One-Wire bus pin for DS18B20.
• ds18b20.setup(ow_pin): Initializes the DS18B20 library to use that pin for communication.
• ds18b20.read(callback, {}): Reads temperature data from all connected DS18B20 sensors.
• The callback function is triggered for each sensor with these parameters:
• ind → Index of the sensor (if multiple sensors are connected).
• rom → Unique 64-bit ROM address of the DS18B20.
• res → Resolution setting of the sensor (9 to 12 bits).
• temp → Integer part of the measured temperature.
• tdec → Decimal part of temperature (precision after decimal point).
• par → Parasite power flag (1 if parasite powered, 0 otherwise).

Output of ESP8266 NodeMCU Interface DSB1820

1   28:FF:4C:60:91:16:05:3C   12   26   5   0
Temp : 26