ShiftOut.cpp

00001 #include "mbed.h"
00002 #include "ShiftOut.h"
00003 
00004 
00005 #define SET_LATCH() (LATCH = 0)
00006 #define RESET_LATCH() (LATCH = 1)
00007 
00008 #define ENABLE_RESET() (RESET = 0)
00009 #define DISABLE_RESET() (RESET = 1)
00010 
00011 static char stateArr[8*REGISTER_CNT] = {0};
00012 static bool hasChanged = false;
00013 
00014 ShiftOut::ShiftOut(PinName ser, PinName srclk, PinName rclk, 
00015                    PinName oe, PinName reset) : DSERIAL(ser), SRCLK(srclk), RCLK(rclk), LATCH(oe), RESET(reset)
00016 {
00017     writeByte(0x00); // Reset the values of the registers to 0  
00018     if(RESET != NC){  
00019     DISABLE_RESET();
00020     }
00021 }
00022 
00023 //Pulses the register
00024 void ShiftOut::updateRegister(){
00025     SRCLK = 1;
00026     wait_us(2);
00027     SRCLK = 0;    
00028 }
00029 //Updates the output register
00030 void ShiftOut::updateOutput(){
00031     RCLK = 1;
00032     wait_us(2);
00033     RCLK = 0;    
00034 }
00035 //Writes a byte to the shift register
00036 void ShiftOut::writeByte(unsigned char byte){
00037     hasChanged = true;
00038     for(int i = 0; i<8*REGISTER_CNT; i++){
00039         DSERIAL = (byte & 0x01<<i)>>i;
00040         updateRegister();    
00041     } 
00042     updateOutput();   
00043 }
00044 //Writes a byte to the shift register
00045 void ShiftOut::write2Byte(unsigned int word){
00046     hasChanged = true;
00047     for(int i = 0; i<8*REGISTER_CNT; i++){
00048         DSERIAL = (word & 0x01<<i)>>i;
00049         updateRegister();    
00050     } 
00051     updateOutput();   
00052 }
00053 //Writes a bit to the shift register
00054 void ShiftOut::writeBit(unsigned char bit){
00055     DSERIAL = bit & 0x01;
00056     updateRegister();
00057     updateOutput();
00058     } 
00059 //Writes multiple bits from an array to create an animation
00060 void ShiftOut::animate(int arr[][8], int lines, int delay_ms){
00061     hasChanged = true;
00062     for(int i = 0; i < lines; i++){
00063         for(int j = 0; j < 8; j++){
00064            writeBit(arr[i][j]); 
00065         } 
00066         wait_ms(delay_ms);   
00067     }
00068 }
00069 
00070 void ShiftOut::animationExample(){
00071     hasChanged = true;
00072     int strobe[][8]= {{1,0,0,0,0,0,0,0},
00073                      {0,1,0,0,0,0,0,0},
00074                      {0,0,1,0,0,0,0,0},
00075                      {0,0,0,1,0,0,0,0},
00076                      {0,0,0,0,1,0,0,0},
00077                      {0,0,0,0,0,1,0,0},
00078                      {0,0,0,0,0,0,1,0},
00079                      {0,0,0,0,0,0,0,1}};
00080                      
00081     int nightrider[18][8]= {{1,0,0,0,0,0,0,0},
00082                            {1,1,0,0,0,0,0,0},
00083                            {1,1,1,0,0,0,0,0},
00084                            {0,1,1,1,0,0,0,0},
00085                            {0,0,1,1,1,0,0,0},
00086                            {0,0,0,1,1,1,0,0},
00087                            {0,0,0,0,1,1,1,0},
00088                            {0,0,0,0,0,1,1,1},
00089                            {0,0,0,0,0,0,1,1},
00090                            {0,0,0,0,0,0,0,1},
00091                            {0,0,0,0,0,0,1,1},
00092                            {0,0,0,0,0,1,1,1},
00093                            {0,0,0,0,1,1,1,0},
00094                            {0,0,0,1,1,1,0,0},
00095                            {0,0,1,1,1,0,0,0},
00096                            {0,1,1,1,0,0,0,0},
00097                            {1,1,1,0,0,0,0,0},
00098                            {1,1,0,0,0,0,0,0}};
00099                         
00100         animate(nightrider, 18, 50);
00101         wait(1);
00102         animate(strobe, 8, 200);
00103     }
00104     
00105 void ShiftOut::writeBitAtPos(unsigned char pin, bool state){
00106     if(hasChanged){
00107         clearStateArray();
00108         hasChanged = false;
00109     } 
00110     if(pin < 8*REGISTER_CNT){
00111         stateArr[pin] = state;        
00112     }
00113     writeArray(stateArr);
00114 }
00115 
00116 void ShiftOut::writeArray(char arr[8*REGISTER_CNT]){
00117     for(int i = (8*REGISTER_CNT)-1; i >= 0; i--) {
00118         writeBit(arr[i]);
00119     }       
00120     
00121 }
00122 
00123 void ShiftOut::clearStateArray(){
00124     for(int i = 0; i < 8*REGISTER_CNT; i++){
00125         stateArr[i] = 0;
00126         }
00127     }