main.cpp

00001 // My AM/FM Radio, Lab 3 Main
00002 // Jammie Proctor
00003 // 03/02/2013
00004 
00005 #include "mbed.h"
00006 #include "TextLCD.h"
00007 
00008 I2C radio(p28, p27);                        // sda, scl
00009 TextLCD lcd(p15, p16, p17, p18, p19, p20);  // rs, e, d4-d7
00010 DigitalIn AM_FM(p22);                       // Radio mode AM/FM
00011 DigitalIn station(p23);                     // Station seek/scan
00012 DigitalOut reset(p21);                      // Radio reset
00013 DigitalOut lock(LED1);                      // Station active
00014 PwmOut rclock(p24);                         // Rclock generation
00015 
00016 //====================================== Global Variables =============================================
00017 const int write_addr=0x22;                          
00018 int fm_pwr_up[3]={0x01, 0x00, 0x05};                    // FM power-up command
00019 int am_pwr_up[3]={0x01, 0x01, 0x05};                    // AM power-up command
00020 int fm_station[4]={0x20, 0x00, 0x22, 0x60};             // Set FM station
00021 int am_station[6]={0x40, 0x00, 0x02, 0x17, 0x00, 0x00}; // Set AM station
00022 float lcd_station=88.0;
00023 int reg_station=8800, reg_am_station=535, i=0, Response, ack=0, pwr_down=0x11, tune=0x31;
00024 int* p_pwr_down = &pwr_down;
00025 int* p_tune = &tune;
00026 bool last_mode=0;
00027 
00028 //===================================== Support Functions =============================================
00029 void SendCommand(int* array, int length) {  /* Send Command to Si4735 */
00030     radio.start();
00031     ack=radio.write(write_addr);
00032     for(i=0; i<length; i++) ack=radio.write(array[i]);
00033     Response=radio.read(ack);
00034     radio.stop();
00035     wait(.2);
00036 }
00037     
00038 void Reset(void) {                          /* Reset AM/FM Radio */
00039     reset=0;
00040     wait(.2);
00041     reset=1;
00042     wait(.2);
00043 }
00044 
00045 void AM_Restart(void) {                     /* Reinitialize AM receiver */                 
00046     SendCommand(p_tune, 1);                         // Disable carrier
00047     wait(.2);
00048     SendCommand(p_pwr_down, 1);                     // Power down sequence
00049     wait(.2); 
00050     Reset();
00051     SendCommand(am_pwr_up, 3);                      // Launch AM 
00052     SendCommand(am_station, 6);                     // Play current AM station
00053 }
00054 
00055 void FM_Restart(void) {                     /* Reinitialize FM receiver */                          
00056     SendCommand(p_tune, 1);                         // Disable carrier
00057     wait(.2);
00058     SendCommand(p_pwr_down, 1);                     // Power down sequence
00059     wait(.2); 
00060     Reset();
00061     SendCommand(fm_pwr_up, 3);                      // Launch FM
00062     SendCommand(fm_station, 4);                     // Play current FM station
00063 }
00064 //================================================ Main Code =======================================================
00065 int main() {
00066     AM_FM.mode(PullUp);
00067     station.mode(PullUp);
00068     lock=0;
00069     rclock.period(.000030518);                  // Set rclock oscillator to 32.768kHz
00070     rclock=0.5;                                 // 50% Duty Cycle for rclock
00071     radio.frequency(100000);                    // I^2C frequency setting 100kHz
00072     Reset();                                   
00073     SendCommand(fm_pwr_up, 3);                  // Initialize FM
00074     SendCommand(fm_station, 4);                 // Play default fm station
00075     last_mode=AM_FM;
00076         
00077     while(1) {
00078         if(AM_FM) {                                 // FM selected (SW1 in the off position)
00079             if(AM_FM!=last_mode) FM_Restart();      
00080             last_mode=AM_FM;
00081             if(!station) {                          // SW2 pressed? Go to next station
00082                 lock=0;
00083                 while(!station);
00084                 if(reg_station<10800) reg_station+=10;
00085                 else reg_station=8800;
00086                 lcd_station=reg_station/100.0;
00087                 fm_station[3]=reg_station&0x00FF;
00088                 fm_station[2]=reg_station>>8;
00089                 SendCommand(fm_station, 4);          
00090                 lock=1;       
00091             }
00092             lcd.printf("Station:\n %3.1fMHz FM", lcd_station);
00093             wait(.1);
00094             lcd.cls();
00095         }
00096         else {                                              // AM selected (SW1 in the on position)
00097             if(AM_FM!=last_mode) AM_Restart();
00098             last_mode=AM_FM;
00099             if(!station) {                                  // SW2 pressed? Go to next station
00100                 lock=0;
00101                 while(!station);
00102                 if(reg_am_station<1700) reg_am_station+=5;
00103                 else reg_am_station=530;
00104                 am_station[3]=reg_am_station&0x00FF;
00105                 am_station[2]=reg_am_station>>8;
00106                 SendCommand(am_station, 6);                 
00107                 lock=1;       
00108             }
00109             lcd.printf("Station:\n %ukHz AM", reg_am_station);
00110             wait(.1);
00111             lcd.cls();
00112         }
00113     }
00114 }