main.cpp

00001 #include "mbed.h"
00002 #include "TextLCD.h"
00003 #include "USBHID.h"
00004 
00005 //for debugging
00006 Serial pc(USBTX, USBRX);
00007 
00008 //an LED to display activity
00009 DigitalOut hid_activity_led(LED2);
00010 DigitalOut alive_led(LED1);
00011 
00012 //The TextLCD
00013 TextLCD lcd(p21, p22, p17, p18, p19, p20); // rs, e, d4-d7
00014 
00015 //the mbed doesn't return the report ID.
00016 union hid_report_t {
00017     uint8_t bytes[sizeof(int16_t)*2];
00018     struct {
00019         uint16_t health;
00020         uint16_t ammo;
00021     } data;
00022 };
00023 
00024 //We declare a USBHID device.
00025 // output report size = 1 (not needed here)
00026 // input report size matches the one defined above
00027 USBHID hid(sizeof(int16_t)*2, 1);
00028 
00029 //This report will contain data to be received
00030 HID_REPORT recv_report;
00031 
00032 int main() {
00033     //initialise the LCD
00034     lcd.printf("     CRYSIS\n  Maximum mbed");
00035     pc.printf("ready!\r\n");
00036     uint16_t health, ammo;
00037     
00038     while(1) {
00039         if(hid.readNB(&recv_report)) {
00040             pc.printf("recv[%d]: ", recv_report.length);
00041             for(int i = 0; i < recv_report.length; i++) {
00042                 pc.printf("%d ", recv_report.data[i]);
00043             }
00044             pc.printf("\r\n");
00045 
00046             //receive data
00047             hid_report_t* pHidData = (hid_report_t*)(recv_report.data);
00048             
00049             //for some reason, the byte order has been changed!
00050             //negative number support will need sign extension
00051             health = __REV16(pHidData->data.health);
00052             ammo = __REV16(pHidData->data.ammo);
00053             
00054             //for debugging...
00055             //pc.printf("Health: %d, Ammo: %d\r\n", health, ammo);
00056             //pc.printf("HEX: Health: %x, Ammo: %x\r\n", health, ammo);
00057             
00058             //write new values on screen.
00059             lcd.cls();
00060             lcd.printf("Health: %d\nAmmo: %d", health, ammo);
00061             hid_activity_led = hid_activity_led == 0 ? 1 : 0;//show HID activity
00062         }
00063         
00064         //toggle an LED to show us, that the mbed is alive.
00065         wait(0.1);
00066         alive_led = alive_led == 0 ? 1 : 0;
00067     }
00068 }