main.cpp

00001 #include "mbed.h"
00002 #include <math.h>
00003 #include "USBJoystick.h"
00004 #include "PwmIn.h"
00005 
00006 //InterruptIn button(USER_BUTTON);
00007 //#define DEBUG_PRINTF
00008 
00009 DigitalOut led(LED1);
00010 
00011 PwmIn a(PB_1); /**< Plug channel 1 from receiver to this pin */
00012 PwmIn b(PC_4); /**< Plug channel 2 from receiver to this pin */
00013 PwmIn c(PC_5); /**< Plug channel 3 from receiver to this pin */
00014 PwmIn d(PC_8); /**< Plug channel 4 from receiver to this pin */
00015 
00016 /**@note Do not forget to plug ground pin to GND of the board */
00017 
00018 /** Covert PWM output which is in floats in range of 0.000153231 to -127..128 range
00019  *
00020  * PWM pulse width is in float range which needs to be offset a bit and then
00021  * converted to int8_t range for the PC joystick driver to understand
00022  *
00023  * @param[in] pwm PWM float value produced by PwmIn.pulseWidth function
00024  *
00025  * @return Converted signed integer value in range of -127..128
00026  */
00027 int16_t covert_PWM_to_PC_range(float pwm)
00028 {
00029     int32_t ipwm = pwm * 1000000;
00030     if(ipwm != 0) {
00031         ipwm = (((ipwm - 1100) * 255) / 870) - 127;   
00032     }
00033     
00034     return (int16_t) ipwm;
00035 }
00036 
00037 int main(void)
00038 {
00039 #ifndef DEBUG_PRINTF
00040     USBJoystick joystick; /**< Joystick object from USBJoystick library */
00041 #else
00042     Serial pc(USBTX, USBRX); /**< USB interface through debugger (/dev/ttyACM0) */
00043     pc.baud(115200); /** Set USB speed for the PC interface */
00044 #endif
00045     uint16_t i = 0;
00046     int16_t throttle = 0;
00047     int16_t rudder = 0;
00048     int16_t x = 0;
00049     int16_t y = 0;
00050     uint8_t tmp = 0;
00051     uint32_t buttons = 0;
00052     uint8_t hat = 0;
00053 
00054     led = 1;
00055 #ifdef DEBUG_PRINTF
00056     pc.printf("Hello World from Joystick!\r\n");
00057 #endif
00058     
00059     while (1) {
00060         /** Get PWM pulsewidth via PwmIn library and covert that to simple
00061          * int8_t range for all 4 channels */
00062         x = covert_PWM_to_PC_range(a.pulsewidth());
00063         y = covert_PWM_to_PC_range(b.pulsewidth());
00064         throttle = covert_PWM_to_PC_range(c.pulsewidth());
00065         rudder = covert_PWM_to_PC_range(d.pulsewidth());
00066 
00067 /*
00068 #if (BUTTONS4 == 1)
00069         buttons = (i >> 8) & 0x0F;   // value    0 ..  15, one bit per button
00070 #endif
00071 #if (BUTTONS8 == 1)
00072         buttons = (i >> 8) & 0xFF;   // value    0 .. 255, one bit per button
00073 #endif
00074 #if (BUTTONS32 == 1)
00075         tmp     = (i >> 8) & 0xFF;   // value    0 .. 255, one bit per button
00076         buttons =           (( tmp <<  0) & 0x000000FF);
00077         buttons = buttons | ((~tmp <<  8) & 0x0000FF00);
00078         buttons = buttons | (( tmp << 16) & 0x00FF0000);
00079         buttons = buttons | ((~tmp << 24) & 0xFF000000);
00080 #endif
00081 
00082 #if (HAT4 == 1)
00083         hat    = (i >> 8) & 0x03;   // value 0, 1, 2, 3 or 4 for neutral
00084 #endif
00085 #if (HAT8 == 1)
00086         hat    = (i >> 8) & 0x07;   // value 0..7 or 8 for neutral
00087 #endif
00088 */
00089         
00090 #ifndef DEBUG_PRINTF
00091         joystick.update(rudder, throttle, y, x, 0, 0);
00092 #else
00093         pc.printf("x (CH1): %i\t\ty (CH2): %i\t\t throttle: %i\r\n", y, x,throttle);
00094 #endif
00095         wait(0.005);
00096     }
00097 }