main.cpp

00001 #include "mbed.h"
00002 #include "MCP23017.h"
00003 
00004 const unsigned __int64 FORWARD = 1;
00005 const unsigned __int64 BACKWARD = 0;
00006 const unsigned __int64 LIGHTON = 1;
00007 const unsigned __int64 LIGHTOFF = 0;
00008 const unsigned __int64 SLOW = 0x4; //0100 = step 5
00009 const unsigned __int64 NORM = 0x9; //1001 = step 15
00010 const unsigned __int64 FAST = 0xE; //1110 = step 25
00011 const unsigned __int64 STOP = 0x1; //0001 = E-STOP
00012 
00013 const unsigned __int64 train1 = 0x1; 
00014 const unsigned __int64 train3 = 0x3;
00015 const unsigned __int64 def_repeat_count = 5;
00016 
00017 int interrupted = 0;
00018     
00019 DigitalOut Track(p20);
00020 DigitalOut led(LED1);
00021 InterruptIn int0(p8);
00022 InterruptIn int1(p9);
00023 MCP23017 *mcp;
00024 
00025 void initialize_mcp() {
00026     mcp = new MCP23017(p28, p27, 0x40);  // Connect to mbed int pins 27 and 28,
00027                                         // MCP address is 0x40
00028     mcp->reset();
00029     mcp->writeRegister(0x00, (unsigned char )0xff);
00030     mcp->writeRegister(0x01, (unsigned char )0xff);
00031     mcp->writeRegister(0x02, (unsigned char )0x00);
00032     mcp->writeRegister(0x03, (unsigned char )0x00);
00033     mcp->writeRegister(0x04, (unsigned char )0xff);
00034     mcp->writeRegister(0x05, (unsigned char )0xff);
00035     mcp->writeRegister(0x06, (unsigned char )0xff); 
00036     mcp->writeRegister(0x07, (unsigned char )0xff);
00037     mcp->writeRegister(0x08, (unsigned char )0xff);
00038     mcp->writeRegister(0x09, (unsigned char )0xff);
00039     mcp->writeRegister(0x0a, (unsigned char )0x42);
00040     mcp->writeRegister(0x0b, (unsigned char )0x42);
00041     mcp->writeRegister(0x0c, (unsigned char )0x00);
00042     mcp->writeRegister(0x0d, (unsigned char )0x00);
00043     
00044     wait_ms(100);
00045     mcp->readRegister(GPIO);
00046 }
00047 
00048 void DCC_send_command(unsigned int address, unsigned int inst, unsigned int repeat_count){
00049     unsigned __int64 command = 0x0000000000000000; // this is a 64-bit integer type, due to the packet size
00050     unsigned __int64 temp_command = 0x0000000000000000;
00051     unsigned __int64 prefix = 0x3FFF; // 14 1 bits as in the preamble of the data packet
00052     unsigned int error = 0x00; // error byte
00053     //calculate error detection byte with xor
00054     error = address ^ inst;
00055     // combine packet bits in basic DCC format
00056     command = (prefix<<28)|(address<<19)|(inst<<10)|((error)<<1)|0x01;
00057 
00058     int i = 0;
00059 
00060     // repeat DCC command lots of times
00061      while(i < repeat_count) {
00062         temp_command = command;
00063 
00064     //loops throught packet bits enconding and sending out digital pulses for a DCC command
00065         for (int j=0; j<64; j++) {
00066             if((temp_command&0x8000000000000000)==0) { //test packet bit
00067 
00068                 Track=0;
00069                 wait_us(100);
00070                 Track=1;
00071                 wait_us(100);
00072 
00073             } else {
00074 
00075                 Track=0;
00076                 wait_us(58);
00077                 Track=1;
00078                 wait_us(58);
00079 
00080             }
00081 
00082             temp_command = temp_command<<1;
00083         }
00084         i++;
00085     }
00086 }
00087 
00088 unsigned __int64 create_instruction(){
00089     unsigned __int64 instruction = 0x0;
00090     unsigned __int64 direction = FORWARD;
00091     unsigned __int64 lights = LIGHTON;
00092     unsigned __int64 speed = NORM;   
00093     
00094     return instruction = (0x01<<6)|(direction<<5)|(lights<<4)|speed;
00095 }
00096 
00097 void interrupt_handler(){
00098      interrupted = 1;
00099 }
00100 
00101 int main(){
00102     initialize_mcp();
00103     int0.fall(&interrupt_handler);
00104     int1.fall(&interrupt_handler);
00105     unsigned __int64 instruction = 0x0;  
00106      
00107     while(1){    
00108         if(interrupted){
00109             printf("interrupted\n");
00110             mcp->readRegister(INTCAP);
00111             int data = mcp->readRegister(GPIO); // value of GPIO is 0x12 
00112             //modify instructions
00113             printf("%d", data);
00114             led = 1; 
00115             interrupted = 0; 
00116         } else {
00117             led = 0;
00118         }
00119         instruction = (0x01<<6)|(FORWARD<<5)|(LIGHTON<<4)|NORM;
00120         DCC_send_command(train3, instruction, def_repeat_count);
00121     }
00122 }
00123 
00124 /*
00125 Interrupts
00126 INT0 - pin 8
00127 
00128 clock en data pins for I2C communication - data sync - hier lezen na een interrupt
00129 SDA - pin 9
00130 SCL - pin 10
00131 
00132 Sending command signals to train tracks
00133 DAT - pin 20
00134 EN - VOUT
00135 
00136 
00137         instruction = (0x01<<6)|(FORWARD<<5)|(LIGHTON<<4)|STOP;
00138         DCC_send_command(train3, instruction, def_repeat_count);
00139 */