6. Case 05: Water Temperature Detection

6.1. Introduction

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• Fishes are poikilotherm whose body temperature changes as the ambient water temperature changes, thus, the water temperature plays a vital role in the growth of fishes.

6.2. Function

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• Dectect the water temperature with the DS18B20 sensor and display them on OLED screen.

6.3. Products Link

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• 1 x microbit Smart Agriculture Kit

6.4. Picture

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6.5. Hardware Connection

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Connect DS18B20 to P1 and the OLED to IIC on IoT:bit.

6.6. Software Programming

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Click “Advanced” in the MakeCode to see more choices.

For programming, we need to add a package: click “Extensions” at the bottom of the MakeCode drawer and search with “iot-environment-kit” in the dialogue box to download it.

Notice: If you met a tip indicating that some codebases would be deleted due to incompatibility, you may continue as the tips say or create a new project in the menu.

6.7. Program

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Initialize the OLED screen as 128×64.

Set DS18B20 sensor to connect to P1 and save the returned value as variable “Temp”.

Clear the OLED screen and display the water temperature.

Link: https://makecode.microbit.org/_Jx2d4JgU6iWj

6.8. Result

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• The OLED displays the water temperature and refreshes every 5 seconds.