Bug in FT8 Telemetry mode and an easy fix. (Atmel tool chain and possibly others) #18

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1. NT7S commented on May 2, 2019

   

   NT7S

   on May 2, 2019

   Member

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   Thank you very much, I will check this soon and push the change when I can verify the fix.
2. sajjsamm commented on Apr 16, 2020

   

   sajjsamm

   on Apr 16, 2020

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   I have the same problem with Arduino and bluepill too. in decoding the message with WSJT-X the last char of message is getting truncated. the SquirrelEng solution didn't work for me.
3. dl9sau commented on Aug 18, 2021

   

   dl9sau

   on Aug 18, 2021

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   I had the same problem.

   Plus another problem:
   a normal message like "73 DL9SAU" is interpreted as hex telemetry.
   The code checks for hex until blank. If blank is reached, or end of string, the function ends. It has detected at this stage "73" as hex string. -> 0x73..... (rest are fill characters) are transmitted.

   Furthermore, there is much useless copying aroound array c18.

   -> This fixes the issues:

   --- a/src/JTEncode.cpp
   +++ b/src/JTEncode.cpp
   @@ -839,9 +839,9 @@ void JTEncode::ft8_bit_packing(char* message, uint8_t* codeword)
    	uint8_t n3 = 0;
    	uint8_t qa[10];
    	uint8_t qb[10];
   -	char c18[19];
   +	//char c18[19];
    	bool telem = false;
   -	char temp_msg[19];
   +	//char temp_msg[19];
    	memset(qa, 0, 10);
    	memset(qb, 0, 10);
   
   @@ -852,10 +852,14 @@ void JTEncode::ft8_bit_packing(char* message, uint8_t* codeword)
    	// Has to be hex digits, can be no more than 18
    	for(i = 0; i < 19; ++i)
    	{
   -		if(message[i] == 0 || message[i] == ' ')
   +		//if(message[i] == 0 || message[i] == ' ')
   +		if(message[i] == 0)
    		{
    			break;
    		}
   +		// bugfix: "73     DL9SAU" was interpreted as hex message. Check further for non-hex-character
   +		else if (message[i] == ' ')
   +			continue;
    		else if(hex2int(message[i]) == -1)
    		{
    			telem = false;
   @@ -863,7 +867,7 @@ void JTEncode::ft8_bit_packing(char* message, uint8_t* codeword)
    		}
    		else
    		{
   -			c18[i] = message[i];
   +			// c18[i] = message[i]; // not necessary. only if telemetry, it's used. First thing done below is, set c18 to 0.
    			telem = true;
    		}
    	}
   @@ -882,6 +886,7 @@ void JTEncode::ft8_bit_packing(char* message, uint8_t* codeword)
    			}
    		}
   
   +#ifdef notdef
    		memset(c18, 0, 19);
    		memmove(c18, message, i0 + 1);
    		snprintf(temp_msg, 19, "%*s", 18, c18);
   @@ -895,7 +900,10 @@ void JTEncode::ft8_bit_packing(char* message, uint8_t* codeword)
    	      }
    	    }
    		strcpy(message, temp_msg);
   -
   +#else
   +		for (char *p = message; *p; p++)
   +			if (islower(*p)) *p = toupper(*p);
   +#endif
   
    		uint8_t temp_int;
    		temp_int = message[0] == ' ' ? 0 : hex2int(message[0]);
   
   
4. dl9sau

   added a commit that references this issue on Oct 10, 2021

   FT8 HEX message fix

   ...

   101199e