Note

Hello, welcome to the SunFounder Raspberry Pi & Arduino & ESP32 Enthusiasts Community on Facebook! Dive deeper into Raspberry Pi, Arduino, and ESP32 with fellow enthusiasts.

Why Join?

Expert Support: Solve post-sale issues and technical challenges with help from our community and team.
Learn & Share: Exchange tips and tutorials to enhance your skills.
Exclusive Previews: Get early access to new product announcements and sneak peeks.
Special Discounts: Enjoy exclusive discounts on our newest products.
Festive Promotions and Giveaways: Take part in giveaways and holiday promotions.

👉 Ready to explore and create with us? Click [here] and join today!

Lesson 09: Joystick Module

Note

The Raspberry Pi does not have analog input capabilities, so it needs a module like the PCF8591 ADC DAC Converter Module to read analog signals for processing.

In this lesson, you will learn how to use a Raspberry Pi to interface with a joystick module using the PCF8591 ADC. You’ll be able to read the X and Y positions of the joystick from its analog outputs and detect button presses. This setup demonstrates how to handle both analog and digital inputs on a Raspberry Pi.

Required Components

In this project, we need the following components.

It’s definitely convenient to buy a whole kit, here’s the link:

Name	ITEMS IN THIS KIT	LINK
Universal Maker Sensor Kit	94	Universal Maker Sensor Kit

You can also buy them separately from the links below.

Component Introduction	Purchase Link
Raspberry Pi 5	BUY
Joystick Module	BUY
PCF8591 ADC DAC Converter Module	BUY

Wiring

Note

In this project, we utilized the AIN0 pin of the PCF8591 module, which is linked to a potentiometer on the module through a jumper cap. To prevent data interference, please disconnect the jumper cap from the module. For more details, please refer to the PCF8591 module schematic.

../_images/Lesson_09_Jostick_Module_pi_bb.png

Code

import PCF8591 as ADC  # Import ADC module for analog input
import time  # Import time module for creating delay
from gpiozero import Button  # Import Button for button input

ADC.setup(0x48)  # Set up PCF8591 module at I2C address 0x48

button = Button(17)  # Initialize button connected to GPIO 17

try:
    while True:  # Loop continuously
        print("x:", ADC.read(0))  # Read analog value from channel AIN0
        print("y:", ADC.read(1))  # Read analog value from channel AIN1
        print("sw:", button.is_active)  # Check if button is pressed
        time.sleep(0.2)  # Wait for 0.2 seconds before next loop
except KeyboardInterrupt:
    print("Exit")  # End program on keyboard interrupt

Code Analysis

Import Libraries:

The script starts with importing necessary libraries for the project.

import PCF8591 as ADC  # Import ADC module for analog input
import time  # Import time module for creating delay
from gpiozero import Button  # Import Button for button input

Setup PCF8591 Module:

The PCF8591 module is set up at I2C address 0x48 which allows the Raspberry Pi to communicate with it.
```
ADC.setup(0x48)  # Set up PCF8591 module at I2C address 0x48
```
Initialize Button:

A button is initialized, connected to GPIO pin 17 on the Raspberry Pi.
```
button = Button(17)  # Initialize button connected to GPIO 17
```

Main Loop:

The main part of the script is an infinite loop that continuously reads analog values from two channels of the PCF8591 (AIN0 and AIN1) and checks if the button is pressed. AIN0 and AIN1 are analog pins for the joystick’s X and Y axes.

try:
    while True:  # Loop continuously
        print("x:", ADC.read(0))  # Read analog value from channel AIN0
        print("y:", ADC.read(1))  # Read analog value from channel AIN1
        print("sw:", button.is_active)  # Check if button is pressed
        time.sleep(0.2)  # Wait for 0.2 seconds before next loop

Interrupt Handling:

The script can be exited gracefully using a keyboard interrupt (CTRL+C), which is a common practice in Python for stopping an infinite loop.
```
except KeyboardInterrupt:
    print("Exit")  # End program on keyboard interrupt
```