/*
  Thumb Joystick demo v1.0
  by:http://www.seeedstudio.com
  connect the module to A0&A1 for using;
*/

void setup()
{
    Serial.begin(9600);
}

void loop()
{
    int sensorValue1 = analogRead(A0);
    int sensorValue2 = analogRead(A1);

    Serial.print("The X and Y coordinate is:");
    Serial.print(sensorValue1, DEC);
    Serial.print(",");
    Serial.println(sensorValue2, DEC);
    Serial.println(" ");
    delay(200);
}

cd ~
git clone https://github.com/Seeed-Studio/grove.py

import math
import sys
import time
from grove.adc import ADC


class GroveThumbJoystick:

    def __init__(self, channelX, channelY):
        self.channelX = channelX
        self.channelY = channelY
        self.adc = ADC()

    @property
    def value(self):
        return self.adc.read(self.channelX), self.adc.read(self.channelY)

Grove = GroveThumbJoystick


def main():
    from grove.helper import SlotHelper
    sh = SlotHelper(SlotHelper.ADC)
    pin = sh.argv2pin()

    sensor = GroveThumbJoystick(int(pin), int(pin + 1))

    while True:
        x, y = sensor.value
        if x > 900:
            print('Joystick Pressed')
        print("X, Y = {0} {1}".format(x, y))
        time.sleep(.2)

if __name__ == '__main__':
    main()

pi@raspberrypi:~/grove.py/grove $ python grove_thumb_joystick.py 0
Hat Name = 'Grove Base Hat RPi'
X, Y = 506 484
X, Y = 484 484
X, Y = 506 484
X, Y = 506 487
Joystick Pressed
X, Y = 999 485
X, Y = 310 736
X, Y = 681 484
Joystick Pressed
X, Y = 999 277
Joystick Pressed
X, Y = 999 487
X, Y = 506 484
X, Y = 501 486
X, Y = 509 484
X, Y = 511 486
X, Y = 510 485
^CTraceback (most recent call last):
  File "grove_thumb_joystick.py", line 69, in <module>
    main()
  File "grove_thumb_joystick.py", line 66, in main
    time.sleep(.2)
KeyboardInterrupt

cd yourpath/GrovePi/Software/Python/

nano grove_thumb_joystick.py   # "Ctrl+x" to exit #

import time
import grovepi

# Connect the Grove Thumb Joystick to analog port A0

# GrovePi Port A0 uses Arduino pins 0 and 1
# GrovePi Port A1 uses Arduino pins 1 and 2
# Don't plug anything into port A1 that uses pin 1
# Most Grove sensors only use 3 of their 4 pins, which is why the GrovePi shares Arduino pins between adjacent ports
# If the sensor has a pin definition SIG,NC,VCC,GND, the second (white) pin is not connected to anything

# If you wish to connect two joysticks, use ports A0 and A2 (skip A1)

# Uses two pins - one for the X axis and one for the Y axis
# This configuration means you are using port A0
xPin = 0
yPin = 1
grovepi.pinMode(xPin,"INPUT")
grovepi.pinMode(yPin,"INPUT")

# The Grove Thumb Joystick is an analog device that outputs analog signal ranging from 0 to 1023
# The X and Y axes are two ~10k potentiometers and a momentary push button which shorts the x axis

# My joystick produces slightly different results to the specifications found on the url above
# I've listed both here:

# Specifications
#     Min  Typ  Max  Click
#  X  206  516  798  1023
#  Y  203  507  797

# My Joystick
#     Min  Typ  Max  Click
#  X  253  513  766  1020-1023
#  Y  250  505  769
while True:
    try:
        # Get X/Y coordinates
        x = grovepi.analogRead(xPin)
        y = grovepi.analogRead(yPin)

        # Calculate X/Y resistance
        Rx = (float)(1023 - x) * 10 / x
        Ry = (float)(1023 - y) * 10 / y

        # Was a click detected on the X axis?
        click = 1 if x >= 1020 else 0

        print "x =", x, " y =", y, " Rx =", Rx, " Ry =", Ry, " click =", click
        time.sleep(.5)

    except IOError:
        print "Error"

sudo python grove_thumb_joystick.py