return bestErr;
}
+uint32_t manchesterEncode2Bytes(uint16_t datain) {
+ uint32_t output = 0;
+ uint8_t curBit = 0;
+ for (uint8_t i=0; i<16; i++) {
+ curBit = (datain >> (15-i) & 1);
+ output |= (1<<(((15-i)*2)+curBit));
+ }
+ return output;
+}
+
//by marshmellow
//encode binary data into binary manchester
int ManchesterEncode(uint8_t *BitStream, size_t size)
if (fclow==0) fclow=8;
//set the threshold close to 0 (graph) or 128 std to avoid static
uint8_t threshold_value = 123;
-
+ size_t preLastSample = 0;
+ size_t LastSample = 0;
+ size_t currSample = 0;
// sync to first lo-hi transition, and threshold
// Need to threshold first sample
// Check for 0->1 transition
if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition
- if ((idx-last_transition)<(fclow-2)){ //0-5 = garbage noise
+ preLastSample = LastSample;
+ LastSample = currSample;
+ currSample = idx-last_transition;
+ if (currSample < (fclow-2)){ //0-5 = garbage noise
//do nothing with extra garbage
- } else if ((idx-last_transition) < (fchigh-1)) { //6-8 = 8 waves
+ } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves
+ if (LastSample > (fchigh-2) && preLastSample < (fchigh-1)){
+ dest[numBits-1]=1; //correct last 9 wave surrounded by 8 waves
+ }
dest[numBits++]=1;
- } else if ((idx-last_transition) > (fchigh+1) && !numBits) { //12 + and first bit = garbage
+
+ } else if (currSample > (fchigh+1) && !numBits) { //12 + and first bit = garbage
//do nothing with beginning garbage
- } else { //9+ = 10 waves
+ } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's
+ dest[numBits++]=1;
+ } else { //9+ = 10 sample waves
dest[numBits++]=0;
}
last_transition = idx;
return (int)startIdx;
}
-uint32_t bytebits_to_byte(uint8_t *src, size_t numbits)
+uint32_t bytebits_to_byte(uint8_t* src, size_t numbits)
{
uint32_t num = 0;
for(int i = 0 ; i < numbits ; i++)
// by marshmellow
// takes a array of binary values, start position, length of bits per parity (includes parity bit),
-// Parity Type (1 for odd; 0 for even; 2 for just drop it), and binary Length (length to run)
+// Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run)
size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen)
{
uint32_t parityWd = 0;
parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
BitStream[j++] = (BitStream[startIdx+word+bit]);
}
- j--;
+ j--; // overwrite parity with next data
// if parity fails then return 0
- if (pType != 2) {
- if (parityTest(parityWd, pLen, pType) == 0) return -1;
+ if (pType == 2) { // then marker bit which should be a 1
+ if (!BitStream[j]) return 0;
+ } else {
+ if (parityTest(parityWd, pLen, pType) == 0) return 0;
}
bitCnt+=(pLen-1);
parityWd = 0;
*size = numBits;
return errCnt;
}
+// on successful return 1 otherwise return 0
+int VikingDecode(uint8_t *BitStream,
+ size_t size,
+ size_t *startIdx,
+ uint8_t *id_bits,
+ size_t id_bits_size)
+{
+ //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
+ // otherwise could be a void with no arguments
+ //set defaults
+ uint32_t i = 0;
+ uint32_t lastcheckindex = size - (id_bits_size * 2);
+ int found = 0;
+ while (i < lastcheckindex)
+ {
+ if (memcmp(BitStream + i,id_bits,id_bits_size) == 0)
+ {
+ *startIdx = i;
+ found = 1;
+ break;
+ }
+ i++;
+ }
+ return found;
+}
+
+