├── README
└── readdsc_explore
    └── readdsc_explore.pde


/README:
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1 | Arduino code to dump DSC Keybus packets to the serial bus.
2 | 
3 | A short presentation is here  http://www.house4hack.co.za/?p=410
4 | 


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/readdsc_explore/readdsc_explore.pde:
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  1 | unsigned long lastread=0;
  2 | int datapin = 4;   // 4 on the uno; 1 on the tiny
  3 | int clockpin = 2;  // 2 on the uno ; 2 on the tiny
  4 | 
  5 | #define databytes 14
  6 | int data[databytes];
  7 | int datavalue = 0;
  8 | 
  9 | 
 10 | int bitcounter = 0;
 11 | int dataindex = 0;
 12 | 
 13 | int dataread=0;
 14 | int lastdataread = 0;
 15 | int startbit = 1;
 16 | boolean canprint =false;
 17 | boolean ignorepadding = true;
 18 | unsigned long lastprint = 0;
 19 | 
 20 | #define rxPin 1
 21 | #define txPin 3
 22 | 
 23 | void setup()  {
 24 |   // define pin modes for tx, rx, led pins:
 25 |   Serial.begin(115200);
 26 |   pinMode(datapin, INPUT); 
 27 |   pinMode(clockpin, INPUT);
 28 | 
 29 |   attachInterrupt(0, readbit, CHANGE);
 30 |   data[0] = 0;
 31 |   lastread = micros();
 32 |   lastprint = millis();
 33 | }
 34 | 
 35 | void loop() {
 36 | 
 37 |     unsigned long now = micros(); 
 38 |     if((abs(now - lastread) >1000) && (abs(now - lastread) <10000) && canprint) {
 39 |               if(data[0]!= 0xA && data[0]!= 0x5 && data[0]!= 0){
 40 |                  for(int i=0; i<= dataindex; i++){  Serial.print(data[i], HEX); Serial.print(' '); }
 41 |                   Serial.println();
 42 |               }
 43 |               dataindex = 0;
 44 |               data[dataindex] = 0;
 45 |               datavalue = 0;
 46 |               bitcounter = 0;
 47 |               startbit = 1;
 48 |              ignorepadding = true;
 49 | 
 50 |               canprint = false; 
 51 |               
 52 |     
 53 |     } 
 54 |      
 55 | }
 56 | 
 57 | 
 58 | void readbit(){
 59 |   lastread = micros();
 60 |   int clkstate = digitalRead(clockpin);
 61 |   if(1==1 ) { // watch for noise
 62 |             
 63 |        if(clkstate == LOW) {
 64 |            if(!startbit){
 65 |              if(dataindex != 1 || bitcounter!=0 || !ignorepadding){
 66 |                   data[dataindex] |= datavalue << (7-bitcounter);
 67 |                   datavalue = 0;
 68 |                   
 69 |                   bitcounter++;
 70 |                   if(bitcounter==8){
 71 |                       dataindex++;
 72 |                       data[dataindex] = 0;  
 73 |                       bitcounter = 0;
 74 |                   }
 75 |               } else {
 76 |                 ignorepadding = false;
 77 |               } 
 78 |             } else {
 79 |               startbit -= 1; //eat startbits
 80 |               datavalue = 0;
 81 |             }   
 82 |             
 83 |        } else {    
 84 |            datavalue = digitalRead(datapin);
 85 |        }
 86 | 
 87 |     
 88 |        
 89 |        canprint = true;
 90 |   }     
 91 |  
 92 | 
 93 | }
 94 | 
 95 | 
 96 | 
 97 | 
 98 | 
 99 | 
100 | 


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