ESP8266 - Joystick

Hardware Preparation

Or you can buy the following sensor kit:

Overview of 2-axis Joystick

You may have encountered a Joystick in various places, like a game controller, a toy controller, or even a large machine like an excavator controller.

The joystick is made up of two potentiometers arranged perpendicular to one another and a push button. Thus, it produces the following outputs:

• An analog value ranging from 0 to 1023 that corresponds to the horizontal position (known as the X-coordinate)
• An analog value ranging from 0 to 1023 that corresponds to the vertical position (known as the Y-coordinate)
• A digital value of the push button (either HIGH or LOW)

Therefore:

• Two analog values can be merged to form 2-D coordinates
• Center of the coordinates is the resting position of the joystick
• A test code (presented in the next section) can determine the actual direction of the coordinates

Some applications may use all three outputs, while others may only use a subset of them.

ESP8266 and Joystick

Because the ESP8266 only has one analog input pin, and the joystick needs two, there are two ways to tackle this:

• Analog to Digital Module:
• You can add an external gadget called an Analog to Digital Converter (ADC) module, like the ADS1115 ADC Module.
• This nifty device gives you more analog input pins, letting you connect multiple analog devices, including the joystick.
• Multiplexing Solution:
• Another option is to use a multiplexing solution, where you take turns reading the X and Y axes of the joystick using that single analog input pin.
• This involves switching between the X and Y axes at different times, using a technique called time-division multiplexing.

However, both of these options can be a bit pricey and a tad complicated. Instead, we recommend going for the ESP32 instead of the ESP8266. Check out the ESP8266 - Joystick tutorial for a simpler and more effective way to go about it.

Learn More

• ESP8266 - Joystick - Servo Motor