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main.cpp@1:3b741adc82ea, 2015-04-11 (annotated)
- Committer:
- jordaahh
- Date:
- Sat Apr 11 15:16:52 2015 +0000
- Revision:
- 1:3b741adc82ea
- Parent:
- 0:a28ad0db4228
- Child:
- 2:98a51d3c2e44
LCD screen has been initialised.
Who changed what in which revision?
| User | Revision | Line number | New contents of line | 
|---|---|---|---|
| jordaahh | 0:a28ad0db4228 | 1 | /* Joystick | 
| jordaahh | 0:a28ad0db4228 | 2 | |
| jordaahh | 0:a28ad0db4228 | 3 | Example code of how to read a joystick | 
| jordaahh | 0:a28ad0db4228 | 4 | |
| jordaahh | 0:a28ad0db4228 | 5 | https://www.sparkfun.com/products/9032 | 
| jordaahh | 0:a28ad0db4228 | 6 | |
| jordaahh | 0:a28ad0db4228 | 7 | Craig A. Evans | 
| jordaahh | 0:a28ad0db4228 | 8 | 7 March 2015 | 
| jordaahh | 0:a28ad0db4228 | 9 | */ | 
| jordaahh | 0:a28ad0db4228 | 10 | |
| jordaahh | 0:a28ad0db4228 | 11 | #include "mbed.h" | 
| jordaahh | 1:3b741adc82ea | 12 | #include "N5110.h" | 
| jordaahh | 1:3b741adc82ea | 13 | |
| jordaahh | 0:a28ad0db4228 | 14 | // change this to alter tolerance of joystick direction | 
| jordaahh | 0:a28ad0db4228 | 15 | #define DIRECTION_TOLERANCE 0.05 | 
| jordaahh | 0:a28ad0db4228 | 16 | |
| jordaahh | 0:a28ad0db4228 | 17 | // connections for joystick | 
| jordaahh | 0:a28ad0db4228 | 18 | DigitalIn button(p15); | 
| jordaahh | 0:a28ad0db4228 | 19 | AnalogIn xPot(p16); | 
| jordaahh | 0:a28ad0db4228 | 20 | AnalogIn yPot(p17); | 
| jordaahh | 1:3b741adc82ea | 21 | |
| jordaahh | 1:3b741adc82ea | 22 | // LCD connections | 
| jordaahh | 1:3b741adc82ea | 23 | //vcc, sce, rst, dc, mosi, clk, led | 
| jordaahh | 1:3b741adc82ea | 24 | N5110 lcd(p7,p8,p9,p10,p11,p13,p26); | 
| jordaahh | 1:3b741adc82ea | 25 | |
| jordaahh | 1:3b741adc82ea | 26 | // Output to screen LED's (backlights) | 
| jordaahh | 1:3b741adc82ea | 27 | PwmOut PWM(p26); | 
| jordaahh | 1:3b741adc82ea | 28 | |
| jordaahh | 0:a28ad0db4228 | 29 | // timer to regularly read the joystick | 
| jordaahh | 0:a28ad0db4228 | 30 | Ticker pollJoystick; | 
| jordaahh | 0:a28ad0db4228 | 31 | // Serial for debug | 
| jordaahh | 0:a28ad0db4228 | 32 | Serial serial(USBTX,USBRX); | 
| jordaahh | 0:a28ad0db4228 | 33 | |
| jordaahh | 0:a28ad0db4228 | 34 | // create enumerated type (0,1,2,3 etc. for direction) | 
| jordaahh | 0:a28ad0db4228 | 35 | // could be extended for diagonals etc. | 
| jordaahh | 0:a28ad0db4228 | 36 | enum DirectionName { | 
| jordaahh | 0:a28ad0db4228 | 37 | UP, | 
| jordaahh | 0:a28ad0db4228 | 38 | DOWN, | 
| jordaahh | 0:a28ad0db4228 | 39 | LEFT, | 
| jordaahh | 0:a28ad0db4228 | 40 | RIGHT, | 
| jordaahh | 0:a28ad0db4228 | 41 | CENTRE, | 
| jordaahh | 0:a28ad0db4228 | 42 | UNKNOWN | 
| jordaahh | 0:a28ad0db4228 | 43 | }; | 
| jordaahh | 0:a28ad0db4228 | 44 | |
| jordaahh | 0:a28ad0db4228 | 45 | // struct for Joystick | 
| jordaahh | 0:a28ad0db4228 | 46 | typedef struct JoyStick Joystick; | 
| jordaahh | 0:a28ad0db4228 | 47 | struct JoyStick { | 
| jordaahh | 0:a28ad0db4228 | 48 | float x; // current x value | 
| jordaahh | 0:a28ad0db4228 | 49 | float x0; // 'centred' x value | 
| jordaahh | 0:a28ad0db4228 | 50 | float y; // current y value | 
| jordaahh | 0:a28ad0db4228 | 51 | float y0; // 'centred' y value | 
| jordaahh | 0:a28ad0db4228 | 52 | int button; // button state (assume pull-down used, so 1 = pressed, 0 = unpressed) | 
| jordaahh | 0:a28ad0db4228 | 53 | DirectionName direction; // current direction | 
| jordaahh | 0:a28ad0db4228 | 54 | }; | 
| jordaahh | 0:a28ad0db4228 | 55 | // create struct variable | 
| jordaahh | 0:a28ad0db4228 | 56 | Joystick joystick; | 
| jordaahh | 0:a28ad0db4228 | 57 | |
| jordaahh | 0:a28ad0db4228 | 58 | int printFlag = 0; | 
| jordaahh | 0:a28ad0db4228 | 59 | |
| jordaahh | 0:a28ad0db4228 | 60 | // function prototypes | 
| jordaahh | 0:a28ad0db4228 | 61 | void calibrateJoystick(); | 
| jordaahh | 0:a28ad0db4228 | 62 | void updateJoystick(); | 
| jordaahh | 0:a28ad0db4228 | 63 | |
| jordaahh | 0:a28ad0db4228 | 64 | int main() | 
| jordaahh | 0:a28ad0db4228 | 65 | { | 
| jordaahh | 1:3b741adc82ea | 66 | lcd.init(); | 
| jordaahh | 0:a28ad0db4228 | 67 | calibrateJoystick(); // get centred values of joystick | 
| jordaahh | 0:a28ad0db4228 | 68 | pollJoystick.attach(&updateJoystick,1.0/10.0); // read joystick 10 times per second | 
| jordaahh | 0:a28ad0db4228 | 69 | |
| jordaahh | 0:a28ad0db4228 | 70 | while(1) { | 
| jordaahh | 0:a28ad0db4228 | 71 | |
| jordaahh | 0:a28ad0db4228 | 72 | if (printFlag) { // if flag set, clear flag and print joystick values to serial port | 
| jordaahh | 0:a28ad0db4228 | 73 | printFlag = 0; | 
| jordaahh | 0:a28ad0db4228 | 74 | serial.printf("x = %f y = %f button = %d ",joystick.x,joystick.y,joystick.button); | 
| jordaahh | 0:a28ad0db4228 | 75 | |
| jordaahh | 0:a28ad0db4228 | 76 | // check joystick direction | 
| jordaahh | 0:a28ad0db4228 | 77 | if (joystick.direction == UP) | 
| jordaahh | 0:a28ad0db4228 | 78 | serial.printf(" UP\n"); | 
| jordaahh | 0:a28ad0db4228 | 79 | if (joystick.direction == DOWN) | 
| jordaahh | 0:a28ad0db4228 | 80 | serial.printf(" DOWN\n"); | 
| jordaahh | 0:a28ad0db4228 | 81 | if (joystick.direction == LEFT) | 
| jordaahh | 0:a28ad0db4228 | 82 | serial.printf(" LEFT\n"); | 
| jordaahh | 0:a28ad0db4228 | 83 | if (joystick.direction == RIGHT) | 
| jordaahh | 0:a28ad0db4228 | 84 | serial.printf(" RIGHT\n"); | 
| jordaahh | 0:a28ad0db4228 | 85 | if (joystick.direction == CENTRE) | 
| jordaahh | 0:a28ad0db4228 | 86 | serial.printf(" CENTRE\n"); | 
| jordaahh | 0:a28ad0db4228 | 87 | if (joystick.direction == UNKNOWN) | 
| jordaahh | 0:a28ad0db4228 | 88 | serial.printf(" Unsupported direction\n"); | 
| jordaahh | 0:a28ad0db4228 | 89 | |
| jordaahh | 0:a28ad0db4228 | 90 | } | 
| jordaahh | 0:a28ad0db4228 | 91 | |
| jordaahh | 0:a28ad0db4228 | 92 | } | 
| jordaahh | 0:a28ad0db4228 | 93 | } | 
| jordaahh | 0:a28ad0db4228 | 94 | |
| jordaahh | 0:a28ad0db4228 | 95 | // read default positions of the joystick to calibrate later readings | 
| jordaahh | 0:a28ad0db4228 | 96 | void calibrateJoystick() | 
| jordaahh | 0:a28ad0db4228 | 97 | { | 
| jordaahh | 0:a28ad0db4228 | 98 | button.mode(PullDown); | 
| jordaahh | 0:a28ad0db4228 | 99 | // must not move during calibration | 
| jordaahh | 0:a28ad0db4228 | 100 | joystick.x0 = xPot; // initial positions in the range 0.0 to 1.0 (0.5 if centred exactly) | 
| jordaahh | 0:a28ad0db4228 | 101 | joystick.y0 = yPot; | 
| jordaahh | 0:a28ad0db4228 | 102 | } | 
| jordaahh | 0:a28ad0db4228 | 103 | void updateJoystick() | 
| jordaahh | 0:a28ad0db4228 | 104 | { | 
| jordaahh | 0:a28ad0db4228 | 105 | // read current joystick values relative to calibrated values (in range -0.5 to 0.5, 0.0 is centred) | 
| jordaahh | 0:a28ad0db4228 | 106 | joystick.x = xPot - joystick.x0; | 
| jordaahh | 0:a28ad0db4228 | 107 | joystick.y = yPot - joystick.y0; | 
| jordaahh | 0:a28ad0db4228 | 108 | // read button state | 
| jordaahh | 0:a28ad0db4228 | 109 | joystick.button = button; | 
| jordaahh | 0:a28ad0db4228 | 110 | |
| jordaahh | 0:a28ad0db4228 | 111 | // calculate direction depending on x,y values | 
| jordaahh | 0:a28ad0db4228 | 112 | // tolerance allows a little lee-way in case joystick not exactly in the stated direction | 
| jordaahh | 0:a28ad0db4228 | 113 | if ( fabs(joystick.y) < DIRECTION_TOLERANCE && fabs(joystick.x) < DIRECTION_TOLERANCE) { | 
| jordaahh | 0:a28ad0db4228 | 114 | joystick.direction = CENTRE; | 
| jordaahh | 0:a28ad0db4228 | 115 | } else if ( joystick.y > DIRECTION_TOLERANCE && fabs(joystick.x) < DIRECTION_TOLERANCE) { | 
| jordaahh | 0:a28ad0db4228 | 116 | joystick.direction = UP; | 
| jordaahh | 0:a28ad0db4228 | 117 | } else if ( joystick.y < DIRECTION_TOLERANCE && fabs(joystick.x) < DIRECTION_TOLERANCE) { | 
| jordaahh | 0:a28ad0db4228 | 118 | joystick.direction = DOWN; | 
| jordaahh | 0:a28ad0db4228 | 119 | } else if ( joystick.x > DIRECTION_TOLERANCE && fabs(joystick.y) < DIRECTION_TOLERANCE) { | 
| jordaahh | 0:a28ad0db4228 | 120 | joystick.direction = RIGHT; | 
| jordaahh | 0:a28ad0db4228 | 121 | } else if ( joystick.x < DIRECTION_TOLERANCE && fabs(joystick.y) < DIRECTION_TOLERANCE) { | 
| jordaahh | 0:a28ad0db4228 | 122 | joystick.direction = LEFT; | 
| jordaahh | 0:a28ad0db4228 | 123 | } else { | 
| jordaahh | 0:a28ad0db4228 | 124 | joystick.direction = UNKNOWN; | 
| jordaahh | 0:a28ad0db4228 | 125 | } | 
| jordaahh | 0:a28ad0db4228 | 126 | |
| jordaahh | 0:a28ad0db4228 | 127 | // set flag for printing | 
| jordaahh | 0:a28ad0db4228 | 128 | printFlag = 1; | 
| jordaahh | 0:a28ad0db4228 | 129 | } |