In this lesson, we will carry out an interesting experiment on how to read the data of Silde Potentiomenter module.
39.1 Components to be prepared
39.2 Silde Potentiomenter module
39.2.1 Silde Potentiomenter module
The similarity of the Slide Potentiometer Module and Potentiometer Module lies in: holding three terminals; changing the resistance between the changeable terminal and one end by changing the position of the slider. When the difference is: the Slide Potentiometer usually has a larger power (and size) and can be used directly as a load or connected in serial in the circuit of the load for current limiting. The potentiometer has a smaller power and size,and generally used for voltage sampling in signal circuit.
39.3 Low level and high level
In circuit, the form of binary (0 and 1) is presented as low level and high level.
Low level is generally equal to ground voltage (0V). High level is generally equal to the operating voltage of components.
The low level of Micro:bit is 0V and high level is 3.3V, as shown below. When IO port on Micro:bit outputs high level, low-power components can be directly driven,like LED.
39.4 Circuit
You should connect the components according to the following circuit diagram, and view the pictures with the function “Zoom in”:
39.5 MakeCode programming
In the following part, we will make use of the online MakeCode editor to complete the experiment in this lesson.
39.5.1 Start programming
(1) Log in to the website
1. You need to enter the URL in the address bar of Google Browser:
https://makecode.microbit.org/
2. After the website is successfully opened, the interface as shown below will appear:
(2) Import a project
1. In the HOME interface, click the "Import" button to import the external ".hex" file:
In the pop-up dialog box, select the "Import File", as shown in the following figure:
Click the "Choose File"
Find the code file for this lesson:
BBC_Microbit_Sensor\Code\Lesson_39\BlockCode
Select the file in ".hex" format and click the Open:
2. Notice whether the file has been loaded into the following window, and then click the "Go ahead!" button, as shown in the following figure:
3.You can see the following interface when successfully opening the file:
39.5.2 Run the program
1. After the program is written, connect micro:bit and PC with a Micro USB cable.
2. After micro:bit is connected to the computer, you need to first "Pair device". Click the 
button on the right of 
in the lower left corner, and then click the 
option, as shown in the following figure:
Then click 
in the lower right corner
Then the following dialog box will pop up, select 
, and then click 
After the device is successfully paired, the 
button changes to 
3. Start to download the program to the Micro:bit, click the button 
, and the program will be downloaded directly to the Micro:bit. Then wait for the download completion. When the download is successful, your Micro:bit will restart and run the program you have downloaded before.
4.Then click the button【Show Console Device】on the left, as shown below:
5.Then you will see the waveform below. Slide the Silde Potentiomenter module left and right slowly, and there will be some changes in the waveform.
[Note]
1.If no experimental phenomenon has been detected after clicking the button 
, you need to click the 
button on the right of the 
, and then click the 
, as shown in the following figure:
2. If no experimental phenomenon is observed, you should check whether the USB cable of Micro:bit is successfully connected. If not, please download the program again.
If you have problems, please send us an email: support@adeept.com
39.5.3 Learn the code program
The following instruction blocks will be applied in the program. Please see the description of the function as follows:
Read and print out the data of Silde Potentiomenter module.
39.6 Python programming
39.6.1 Run the program
1.Connect micro:bit and PC with a Micro USB cable.
2. Open the Mu Editor installed on the computer, and click the button [Load] in the upper left corner to open the source code program of this lesson:
Find the code file for this lesson:
BBC_Microbit_Sensor\Code\Lesson_39\PythonCode
Select the file in ".py" format and click the Open:
3.Click button【Flash】 to download the program to the Micro:bit. Click the button 
immediately (click the button 
when the Micro:bit indicator is flashing), and the output data will be read on the console, as shown below:
After downloading the program to Micro:bit successfully, click the button 
, and it will be blank on the console:
4.Slide the Silde Potentiomenter module left and right slowly, and the detected data will be output on the console, as shown below:
【Note】
1. If no data can be read on the console,click button【Flash】for a second time, and click the button 
immediately. If no data have been output yet, please repeat the above steps or check whether the wiring is connected correctly.
If you have problems, please send us an email: support@adeept.com
39.6.2 Learn the code program
The following is an explanation of the course code of this section.
（1）Read the data of Silde Potentiomenter module and print out the data.
11 12 13 14 15 | while True: # define slide potentiometer pin slide_potentiometer = pin0.read_analog() print(slide_potentiometer) sleep(100) |