Sparkfun Analog Joystick

Sparkfun Analog Joystick

An analog joystick for user input for direction, magnitude and push button. Developer can use it for 360 degree freedom.

Overview

Features:

  • Analog Output of X,Y axis voltage
  • Additional Push Button
  • Simple Setup

Pin Setup

Embed PinJoystickLCD
GNDGNDGND
VOutVCC
p18VERT
p19HORZ
p20SEL
VU+5V
p13RX
p14TX
p15Reset

Library

Import librarySparkfunAnalogJoystick

Sparkfun Analog Joystick

Information

Important Note:In our library, we set positive x-axis, y-axis in traditional way.
"right" is positive x
"up" is positive y
However the analog output itself gives "left" as high voltage and "up" as high voltage

Information

Important Note:The raw output is a square area of x range [0,1] and y range [0,1]
We normalize the output to a circle are so that x^2+y^2 range [0,1]

Demo Program

Import programLab4

Sparkfun Analog Joystick Test Program

main.cpp

#include "mbed.h"
#include "SparkfunAnalogJoystick.h"
#include "uLCD_4DGL.h"
 
#define M_PI 3.14159265358979323846
 
SparkfunAnalogJoystick joysttick(p18, p19, p20);
uLCD_4DGL lcd(p13, p14, p15);
 
// Test program for the library
// It would output all data about the joystick
// It would also draw a compass to indicate the joystick status on the LCD display
 
int main() {
    lcd.baudrate(3000000);
    lcd.background_color(0);
    lcd.cls();
    float lastx=0;
    float lasty=0;
    while(1) {
        printf("X-Axis: %f\n\r", joysttick.xAxis());
        printf("Y-Axis: %f\n\r", joysttick.yAxis());
        printf("Angle: %f\n\r", joysttick.angle());
        printf("Distance: %f\n\r", joysttick.distance());
        printf("Button: %d\n\r\n", joysttick.button());
        float distance=joysttick.distance();
        float angle=joysttick.angle();
        float x=distance*cos(angle*M_PI/180)*40;
        float y=distance*sin(angle*M_PI/180)*40;
        lcd.circle(60, 60, 40, WHITE);
        lcd.line(60, 60, 60+lastx, 60-lasty, BLACK);
        lcd.line(60, 60, 60+x, 60-y, WHITE);
        lastx=x;
        lasty=y;     
        wait(0.1);
    }
}

Demo Video

API List

Import library

Public Member Functions

  SparkfunAnalogJoystick (PinName, PinName, PinName)
  Constructor of Joystick object.
int  button ()
  Get the button status.
float  xAxis ()
  X axis value, reverse the value to get the x value in a normal Cartesian coordinate system.
float  yAxis ()
  Y axis value.
float  angle ()
  Calculate the angle value in a polar coordinate system.
float  distance ()
  Calculate the normalized distance value in a polar coordinate system.


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