Raspberry Pi Pico - Joystick - Servo Motor
This guide will show you how to control two servo motors or a pan-tilt kit using a Raspberry Pi Pico and a joystick.
A joystick has two control parts named potentiometers, set in a cross pattern, called the X-axis and Y-axis. These potentiometers create signals, known as X-value and Y-value, which emerge from the VRX and VRY pins of the joystick. We use these signals to operate two servo motors: the X-value controls servo motor #1 and the Y-value controls servo motor #2. When used with a pan-tilt kit, the two servo motors collaborate to move in three dimensions.
The application can be used in two ways:
- Use case 1: Moving the joystick controls the servo motors:
- The servo motors' movement angles correspond to the joystick's left-right (X) and up-down (Y) movements.
- When you release the joystick, it and the servo motors go back to their initial position.
- Use case 2: Use the joystick to direct the servo motors:
- Moving the joystick to the left makes servo motor #1 rotate clockwise.
- Moving the joystick to the right makes servo motor #1 rotate counterclockwise.
- Moving the joystick upward makes servo motor #2 rotate clockwise.
- Moving the joystick downward makes servo motor #2 rotate counterclockwise.
- Releasing the joystick does not change the positions of the servo motors.
- Pushing the joystick's button resets the servo motors to the middle.
- Ensure that Thonny IDE is installed on your computer.
- Ensure that MicroPython firmware is installed on your Raspberry Pi Pico.
- If this is your first time using a Raspberry Pico, refer to the Raspberry Pi Pico - Getting Started tutorial for detailed instructions.
- Connect the Raspberry Pi Pico to the joystick and servo motor according to the provided diagram.
- Connect the Raspberry Pi Pico to your computer using a USB cable.
- Launch the Thonny IDE on your computer.
- On Thonny IDE, select MicroPython (Raspberry Pi Pico) Interpreter by navigating to Tools Options.
- In the Interpreter tab, select MicroPython (Raspberry Pi Pico) from the drop-down menu.
- Ensure the correct port is selected. Thonny IDE should automatically detect the port, but you may need to select it manually (e.g., COM3 on Windows or /dev/ttyACM0 on Linux).
- Navigate to the Tools Manage packages on the Thonny IDE.
- Search “DIYables-MicroPython-Servo”, then find the Servo Motor library created by DIYables.
- Click on DIYables-MicroPython-Servo, then click Install button to install Servo Motor library.
- Search “DIYables-MicroPython-Joystick”, then find the Joystick library created by DIYables.
- Click on DIYables-MicroPython-Joystick, then click Install button to install Joystick library.
- Copy the above code and paste it to the Thonny IDE's editor.
- Save the script to your Raspberry Pi Pico by:
- Click the Save button, or use Ctrl+S keys.
- In the save dialog, you will see two sections: This computer and Raspberry Pi Pico. Select Raspberry Pi Pico
- Save the file as main.py
- Click the green Run button (or press F5) to run the script. The script will execute.
- Push the joystick in any direction.
- Watch the servo motor spin.
- Check out the message in the Shell at the bottom of Thonny.
- Copy the provided MicroPython code and paste it into Thonny's editor.
- Save the code to your Raspberry Pi Pico.
- Click the green Run button (or press F5) to execute the script.
- Move the joystick in any direction.
- Observe the servo motor rotating.
- Check out the message in the Shell at the bottom of Thonny.
Hardware Preparation
Or you can buy the following sensor kits:
| 1 | × | DIYables Sensor Kit (30 sensors/displays) | |
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
Disclosure: Some of the links provided in this section are Amazon affiliate links. We may receive a commission for any purchases made through these links at no additional cost to you.
Additionally, some of these links are for products from our own brand, DIYables.
Additionally, some of these links are for products from our own brand, DIYables.
Overview of Joystick and Servo Motor
If you don't know much about joystick and servo motor details like pinout, functionality, and how to program them, please look at these tutorials to learn more.
Wiring Diagram
This image is created using Fritzing. Click to enlarge image
Raspberry Pi Pico Code
Raspberry Pi Pico Code - The servo motors rotate according to the movement of the joystick's thump
"""
This Raspberry Pi Pico MicroPython code was developed by newbiely.com
This Raspberry Pi Pico code is made available for public use without any restriction
For comprehensive instructions and wiring diagrams, please visit:
https://newbiely.com/tutorials/raspberry-pico/raspberry-pi-pico-joystick-servo-motor
"""
from DIYables_MicroPython_Joystick import Joystick
from DIYables_MicroPython_Servo import Servo
import time
# Define constants for joystick, button, and servo pins
JOYSTICK_X_PIN = 26 # The Raspberry Pi Pico pin connected to the VRX of the joystick
JOYSTICK_Y_PIN = 27 # The Raspberry Pi Pico pin connected to the VRY of the joystick
BUTTON_PIN = 22 # The Raspberry Pi Pico pin connected to the SW of the joystick
SERVO_X_PIN = 6 # The Raspberry Pi Pico pin connected to Servo motor 1
SERVO_Y_PIN = 10 # The Raspberry Pi Pico pin connected to Servo motor 2
# Initialize the joystick with the corresponding pins for X and Y
joystick = Joystick(pin_x=JOYSTICK_X_PIN, pin_y=JOYSTICK_Y_PIN, pin_button=BUTTON_PIN)
# Initialize the two servos
xServo = Servo(SERVO_X_PIN) # Use the constant for the X servo pin
yServo = Servo(SERVO_Y_PIN) # Use the constant for the Y servo pin
# Function to map the joystick value to servo angle
def map_value(value, in_min, in_max, out_min, out_max):
return int((value - in_min) * (out_max - out_min) / (in_max - in_min) + out_min)
# Main loop
while True:
joystick.loop() # Must be called frequently to process joystick data
# Read the X and Y axis values (12-bit resolution from the library)
x_value = joystick.read_x()
y_value = joystick.read_y()
# Map the 12-bit values (0 to 4095) to servo angles (0 to 180 degrees)
x_angle = map_value(x_value, 0, 4095, 0, 180)
y_angle = map_value(y_value, 0, 4095, 0, 180)
# Move the servos to the mapped angles
xServo.move_to_angle(x_angle)
yServo.move_to_angle(y_angle)
# Print the joystick's X and Y values and the corresponding servo angles
print(f'Joystick X: {x_value}, Y: {y_value} => Servo X Angle: {x_angle}°, Y Angle: {y_angle}°')
time.sleep(0.05) # Delay to reduce the output frequency
Detailed Instructions
Please follow these instructions step by step:
Shell x
>>> %Run -c $EDITOR_CONTENT
MPY: soft reboot
MicroPython (Raspberry Pi Pico) • Board CDC @ COM29 ≡
Raspberry Pi Pico Code - Use the joystick to command servo motors
"""
This Raspberry Pi Pico MicroPython code was developed by newbiely.com
This Raspberry Pi Pico code is made available for public use without any restriction
For comprehensive instructions and wiring diagrams, please visit:
https://newbiely.com/tutorials/raspberry-pico/raspberry-pi-pico-joystick-servo-motor
"""
from DIYables_MicroPython_Joystick import Joystick
from DIYables_MicroPython_Servo import Servo
from machine import Pin
import time
# Define constants for joystick, button, and servo pins
JOYSTICK_X_PIN = 26 # The Raspberry Pi Pico pin connected to the VRX of the joystick
JOYSTICK_Y_PIN = 27 # The Raspberry Pi Pico pin connected to the VRY of the joystick
BUTTON_PIN = 22 # The Raspberry Pi Pico pin connected to the SW of the joystick
SERVO_X_PIN = 6 # The Raspberry Pi Pico pin connected to Servo motor 1
SERVO_Y_PIN = 10 # The Raspberry Pi Pico pin connected to Servo motor 2
# Define commands
COMMAND_NO = 0x00
COMMAND_LEFT = 0x01
COMMAND_RIGHT = 0x02
COMMAND_UP = 0x04
COMMAND_DOWN = 0x08
# Define thresholds and intervals
LEFT_THRESHOLD = 1000
RIGHT_THRESHOLD = 3000
UP_THRESHOLD = 1000
DOWN_THRESHOLD = 3000
UPDATE_INTERVAL = 100 # 100ms
# Initialize joystick, servos, and button
joystick = Joystick(pin_x=JOYSTICK_X_PIN, pin_y=JOYSTICK_Y_PIN, pin_button=BUTTON_PIN)
xServo = Servo(SERVO_X_PIN)
yServo = Servo(SERVO_Y_PIN)
# Initialize variables
xAngle = 90 # The center position of servo #1
yAngle = 90 # The center position of servo #2
command = COMMAND_NO
last_update_time = time.ticks_ms()
# Function to ensure the angle stays within the 0 to 180 degree range
def limit_angle(angle):
if angle < 0:
return 0
elif angle > 180:
return 180
return angle
while True:
joystick.loop() # Process joystick data
current_time = time.ticks_ms()
if time.ticks_diff(current_time, last_update_time) > UPDATE_INTERVAL:
last_update_time = current_time
# Read X and Y analog values
x_value = joystick.read_x()
y_value = joystick.read_y()
# Reset command
command = COMMAND_NO
# Check left/right commands
if x_value < LEFT_THRESHOLD:
command |= COMMAND_LEFT
elif x_value > RIGHT_THRESHOLD:
command |= COMMAND_RIGHT
# Check up/down commands
if y_value < UP_THRESHOLD:
command |= COMMAND_UP
elif y_value > DOWN_THRESHOLD:
command |= COMMAND_DOWN
# Print and process commands
if command & COMMAND_LEFT:
print("COMMAND LEFT")
xAngle -= 1
if command & COMMAND_RIGHT:
print("COMMAND RIGHT")
xAngle += 1
if command & COMMAND_UP:
print("COMMAND UP")
yAngle -= 1
if command & COMMAND_DOWN:
print("COMMAND DOWN")
yAngle += 1
# Limit the angles to the range of 0 to 180 degrees
xAngle = limit_angle(xAngle)
yAngle = limit_angle(yAngle)
# Handle button press
if joystick.is_pressed():
print("The button is pressed")
xAngle = 90 # Reset to center position
yAngle = 90
# Move servos to the calculated angles
xServo.move_to_angle(xAngle)
yServo.move_to_angle(yAngle)
# Print servo angles to console
print(f"Servo Motor's Angle: {xAngle}°, {yAngle}°")
Detailed Instructions
Shell x
>>> %Run -c $EDITOR_CONTENT
MPY: soft reboot
MicroPython (Raspberry Pi Pico) • Board CDC @ COM29 ≡
Code Explanation
Look at the explanations in the comments in the source code.