Basic Edge Detection

This section describes how to use VisionFive 2 or VisionFive 2 Lite's GPIO pins to detect the signal of a button (that is, the rising edge and falling edge) through an example program with Python.

Hardware Setup

Connect pin ① and pin ② of the button to the breadboard first, and then connect pin ③ and pin ④ to VisionFive 2 or VisionFive 2 Lite. The following table and figure describe how to connect the button to the 40-pin GPIO Header:


Button	40-Pin GPIO Header
Button	Pin Number	Pin Name
Pin ④	37	GPIO60
Pin ③	39	GND

Run Demo Code

Perform the following steps on Debian of VisionFive 2 or VisionFive 2 Lite.

Locate the directory where the test code, basic_edge_detection.py, exists.
1. Source into the Python3 Virtual Environment.
```
source ./myvenv/bin/activate
```
2. Install the dependency.
```
python3 -m pip install pillow
```
3. Get the directory where VisionFive.gpio exists.
```
python3 -m pip show VisionFive.gpio
```
  Note: The output depends on how the application is installed.
4. Enter the VisionFive.gpio directory.
```
cd <VisionFive.gpio directory>
```
5. Enter the sample-code directory.
```
cd ./VisionFive/sample-code/
```
Under the sample-code directory, execute the following command to run the demo code.
```
sudo python  basic_edge_detection.py
```
Alternatively, you can also run the following command.
```
sudo python3  basic_edge_detection.py
```
The terminal displays the following:
```
# python3 basic_edge_detection.py 
*-----------------------Case 1-------------------------*
Please press the key on pin 37 once at any time !!!
```
Press the button, and the terminal displays the following:
```
*-----------------------------------*
Falling edge is detected on pin 37 !

*-----------------------------------*
Rising edge is detected on pin 37 !
```
Note: For details about the source code, see basic_edge_detection.py Source Code.
(Optional) Exit the Python3 Virtual Environment.
```
deactivate
```