' Test program for Adafruit Mini I2C Gamepad with seesaw
' -----------------------------------------------------------------------
Option EXPLICIT
Option DEFAULT INTEGER

' -----------------------------------------------------------------------
' Definitions
' -----------------------------------------------------------------------
Const GPAD_ADDR     = &H50               ' I2C Address
Const GPAD_SDA_PIN  = MM.Info(PinNo GP0) ' SDA pin
Const GPAD_SCL_PIN  = MM.Info(PinNo GP1) ' SCL pin
Const GPAD_I2C_FREQ = 400

' Seesaw Registers
Const GPAD_REG_GPIO = &H01
Const GPAD_REF_ADC  = &H09

' Seesaw GPIO Functions
Const GPIO_DIRCLR   = &H03               ' Direction Clear (Set to Input)
Const GPIO_BULK     = &H04               ' Read all GPIO
Const GPIO_SET      = &H05               ' Set Output High (for pull-ups)
Const GPIO_PULLEN   = &H0B               ' Pull-up Enable

' Seesaw ADC Functions
Const ADC_READ      = &H07

' Button Pin Mappings (Bit positions)
' Select=0, B=1, Y=2, A=5, X=6, Start=16
Const PIN_SELECT    = 0
Const PIN_B         = 1
Const PIN_Y         = 2
Const PIN_A         = 5
Const PIN_X         = 6
Const PIN_START     = 16

' Joystick Pins
Const JOY_X_PIN     = 14
Const JOY_Y_PIN     = 15

' Gamepad data type
Type TGamePad
  joyX As Integer                       ' Joystick values
  joyY As Integer
  StartBtn  As Integer                  ' Buttons
  SelBtn As Integer
  BtnA As Integer
  BtnB As Integer
  BtnX As Integer
  BtnY As Integer
End Type

' -----------------------------------------------------------------------
Dim gpData As TGamePad

Do
 gpData = SeesawGamePad()

 Print @(0,0) "Joystick x=";Str$(gpData.joyX, 4, 0);
 Print " y=";Str$(gpData.joyY, 4, 0);" ";
 Print "Buttons: ";
 If gpData.StartBtn Then Print "START " Else Print "_____ ";
 If gpData.SelBtn Then Print "SEL "; Else Print "___ ";
 If gpData.BtnA Then Print "A "; Else Print "_ ";
 If gpData.BtnB Then Print "B "; Else Print "_ ";
 If gpData.BtnX Then Print "X "; Else Print "_ ";
 If gpData.BtnY Then Print "Y "; Else Print "_ ";
 Print

 Pause 50
Loop
End

' =======================================================================
' Gamepad function
' -----------------------------------------------------------------------
Function SeesawGamePad() As TGamePad
 ' Reads out the connected Adafruit Mini I2C Gamepad with seesaw
 ' On the first call, it initializes the GamePad
 Static Integer isFirst = 1, rBuf(3), buttons

 If isFirst Then
   ' Configure I2C
   Print "Initializing I2C ..."
   SetPin GPAD_SDA_PIN, GPAD_SCL_PIN, I2C
   I2C OPEN 400, 500

   ' Create Pin Mask for all buttons. This tells the controller which
   ' pins we are configuring. Seesaw expects 4 bytes (32-bit word),
   ' Big Endian (MSB first), hence mask bytes: 00, 01, 00, 67
   Print "Configuring Gamepad ..."
   ' 1. Set Direction to INPUT (DIRCLR)
   I2C WRITE GPAD_ADDR, 0, 6, GPAD_REG_GPIO, GPIO_DIRCLR, 0, 1, 0, &H67
   Pause 10
   ' 2. Enable Pull-up resistors (PULLENSET)
   I2C WRITE GPAD_ADDR, 0, 6, GPAD_REG_GPIO, GPIO_PULLEN, 0, 1, 0, &H67
   Pause 10
   ' 3. Set Pull-ups High (GPIO_SET)
   I2C WRITE GPAD_ADDR, 0, 6, GPAD_REG_GPIO, GPIO_SET, 0, 1, 0, &H67
   Pause 10
   Print "Done."
   IsFirst = 0
 EndIf

 ' Read buttons
 I2C WRITE GPAD_ADDR, 1, 2, GPAD_REG_GPIO, GPIO_BULK
 Pause 3
 I2C READ GPAD_ADDR, 0, 4, rBuf()

 ' Reconstruct the 32-bit status from 4 bytes (Big Endian)
 ' Note: Logic is inverted because of Pull-ups (0=Pressed, 1=Released)
 buttons = (rBuf(0) << 24) Or (rBuf(1) << 16) Or (rBuf(2) << 8) Or rBuf(3)
 SeesawGamePad.StartBtn = (buttons And (1 << PIN_START)) = 0
 SeesawGamePad.SelBtn = (buttons And (1 << PIN_SELECT)) = 0
 SeesawGamePad.BtnA = (buttons And (1 << PIN_A)) = 0
 SeesawGamePad.BtnB = (buttons And (1 << PIN_B)) = 0
 SeesawGamePad.BtnX = (buttons And (1 << PIN_X)) = 0
 SeesawGamePad.BtnY = (buttons And (1 << PIN_Y)) = 0

 ' Read joystick x
 I2C WRITE GPAD_ADDR, 0, 2, GPAD_REF_ADC, ADC_READ +JOY_X_PIN
 Pause 3
 I2C READ GPAD_ADDR, 0, 2, rBuf()
 SeesawGamePad.joyX = 1023 -((rBuf(0) << 8) Or rBuf(1))

 ' Read joystick y
 I2C WRITE GPAD_ADDR, 0, 2, GPAD_REF_ADC, ADC_READ +JOY_Y_PIN
 Pause 3
 I2C READ GPAD_ADDR, 0, 2, rBuf()
 SeesawGamePad.joyY = 1023 -((rBuf(0) << 8) Or rBuf(1))
End Function

' -----------------------------------------------------------------------