ESP8266 - Joystick - Servo Motor
A joystick is equipped with two potentiometers that are perpendicular to each other (known as the X-axis and Y-axis). These potentiometers output analog values (X-value and Y-value) on VRX and VRY pins. We will use these analog values to independently control two servo motors: X-value controls servo #1 and Y-value controls servo #2. When using a pan-tilt kit, the combination of the two servo motors creates three-dimensional movement.
There are two use cases:
- Use case 1: The servo motors rotate according to the movement of the joystick's thump:
- The angles of servo motors are in proportion to the values of the joystick's X-value and Y-value.
- When the joystick's thump is released, all values return back to the center values and the servo motors automatically go back to the center position.
- Use case 2: Use the joystick to command servo motors (up/down/left/right commands)
- When the joystick's thump is pushed to the left, move the servo motor #1 in a clockwise direction.
- When the joystick's thump is pushed to the right, move the servo motor #1 in an anti-clockwise direction.
- When the joystick's thump is pushed up, move the servo motor #2 in clockwise direction.
- When the joystick's thump is pushed down, move the servo motor #2 in an anti-clockwise direction.
- When the joystick's thump is released, the servo motors will not return to the center position.
- If the joystick is pressed (push button), the servo motors will return to the center position.
- Analog to Digital Module:
- You can use an external Analog to Digital Converter (ADC) module like the popular ADS1115 ADC Module.
- This module lets you connect multiple analog devices, expanding the available analog input pins.
- Multiplexing Solution:
- Another option is to implement a multiplexing solution. This involves switching between reading the X and Y axes of the joystick using the single available analog input pin.
- Essentially, you switch back and forth between X and Y readings, achieving the desired functionality through time-division multiplexing.
Hardware Preparation
Or you can buy the following sensor kits:
| 1 | × | DIYables Sensor Kit (30 sensors/displays) | |
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
Additionally, some of these links are for products from our own brand, DIYables.
Overview of Joystick and Servo Motor
If you are unfamiliar with joystick and servo motor (including pinout, functionality, programming, etc.), the following tutorials can help:
Since the ESP8266 has only one analog input pin, and the joystick needs two, there are two ways to solve this:
However, both these solutions can be a bit costly and complicated. For a simpler approach, we highly recommend using the ESP32 instead of the ESP8266. Check out the ESP8266 - Joystick tutorial for a more user-friendly implementation.