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VK1ET : Decode mode ASCII hex input message types

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Modifications entirely base on code supplied by John VK1ET.

Supports additional AVR raw ASCII input message stream types
This commit is contained in:
Malcolm Robb 2013-04-24 20:46:59 +01:00
parent a04e399d7e
commit 3dbc0efffc
1 changed files with 50 additions and 27 deletions
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77
dump1090.c
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@ -2962,40 +2962,63 @@ int decodeHexMessage(struct client *c) {
unsigned char msg[MODES_LONG_MSG_BYTES];
struct modesMessage mm;
/* Remove spaces on the left and on the right. */
while(l && isspace(hex[l-1])) {
hex[l-1] = '\0';
l--;
}
while(isspace(*hex)) {
hex++;
l--;
}
/* Turn the message into binary. */
if (l < 2 || (hex[0] != '*' && hex[0] != '@') || hex[l-1] != ';') return 0;
if (hex[0] == '@') {
hex += 13; l -= 15; // Skip @, and timestamp, and ;
} else {
hex++; l-=2; // Skip * and ;
}
if (l > MODES_LONG_MSG_BYTES*2) return 0; /* Too long message... broken. */
for (j = 0; j < l; j += 2) {
int high = hexDigitVal(hex[j]);
int low = hexDigitVal(hex[j+1]);
if (high == -1 || low == -1) return 0;
msg[j/2] = (high<<4) | low;
}
// Always mark the timestamp as invalid for packets received over the internet
// Mixing of data from two or more different receivers and publishing
// as coming from one would lead to corrupt mlat data
// Non timemarked internet data has indeterminate delay
mm.timestampMsg = -1;
mm.signalLevel = -1;
decodeModesMessage(&mm,msg);
// Remove spaces on the left and on the right
while(l && isspace(hex[l-1])) {
hex[l-1] = '\0'; l--;
}
while(isspace(*hex)) {
hex++; l--;
}
// Turn the message into binary.
// Accept *-AVR raw @-AVR/BEAST timeS+raw %-AVR timeS+raw (CRC good) <-BEAST timeS+sigL+raw
// and some AVR recorer that we can understand
if (hex[l-1] != ';') {return (0);} // not complete - abort
switch(hex[0]) {
case '<': {
mm.signalLevel = (hexDigitVal(hex[13])<<4) | hexDigitVal(hex[14]);
hex += 15; l -= 16; // Skip <, timestamp and siglevel, and ;
break;}
case '@':
case '%':
case '#':
case '$': {
hex += 13; l -= 14; // Skip @,%,#,$, and timestamp, and ;
break;}
case '*':
case ':': {
hex++; l-=2; // Skip * and ;
break;}
default: {
return (0); // We don't know what this is, so abort
break;}
}
if ( (l < 4) || (l > MODES_LONG_MSG_BYTES*2) ) return (0); // Too short or long message... broken
for (j = 0; j < l; j += 2) {
int high = hexDigitVal(hex[j]);
int low = hexDigitVal(hex[j+1]);
if (high == -1 || low == -1) return 0;
msg[j/2] = (high<<4) | low;
}
if (l < 5) {decodeModeAMessage((uint)((msg[0]<<8) + msg[1]), &mm);} // ModeA or ModeC
else {decodeModesMessage(&mm, msg);}
useModesMessage(&mm);
return 0;
return (0);
}
/* Return a description of planes in json. */