Converting Char array of HEX into Text

Projects Programming
1

Hello i have a

char sms_text[250];

wich contains a HEX value like this

006C00610074003A00330037002E003900350037003100390020006C006F006E0067003A00320033002E00370035003000370030002000730070006500650064003A00300

i want to convert it to this and store it in a string Variable..

lat:37.9899 long:23.74470 speed:0

2 
330037002E00390035003700310039

3 7 . 9 5 7 1 9

320033002E00370035003000370030

2 3 . 7 5 0 7 0

6C00610074

L a t

3

yes i know , but what i mean is how can i do it programmatically?

4

If a byte is an ASCII digit, subtract '0' (aka 0x30)
If it's a decimal point (aka full-stop or period) leave it alone.
If it's an alphabetic character, leave it.

5

Your text has 137 single characters, each group of 4 denotes a resultcharacter, ups, it should be divisible.
There is one superfluous character I think.

6 
char orgMsg[] = "006C00610074003A0033"
                "0037002E003900350037"
                "003100390020006C006F"
                "006E0067003A00320033"
                "002E0037003500300037"
                "00300020007300700065"
                "00650064003A00300";

char resMsg[126];

byte omsgLen = sizeof(orgMsg) - 1;

void setup() {
  Serial.begin(115200);
  byte offs = 0;
  for (offs = 0; offs + 3 < omsgLen; offs += 4) {
    resMsg[offs / 4] = getByteAt(orgMsg, offs);
  }
  resMsg[offs / 4] = 0;
  Serial.print(F("res = '"));
  Serial.print(resMsg);
  Serial.println(F("'"));
}

byte getHexVal(char cx) {
  if (cx <= '0') {
    return 0;
  }
  if (cx <= '9') {
    return cx - '0';
  }
  if (cx >= 'A' && cx <= 'F') {
    return cx - 'A' + 10;
  }
  return 0;
}
char getByteAt(char* from, byte offset) {
  return getHexVal(from[offset + 2]) * 16 + getHexVal(from[offset + 3]);
}
void loop() {}

res = 'lat:37.95719 long:23.75070 speed:0'
7

Thank you very very much , i think this will help a lot of people,
working like a charm

8

gc9n:
Hello i have a

char sms_text[250];

From some device outside of your control, or did you create the string in the first place?

9

from a gps tracker it sends me in PDU not in text