What is wrong with Serial.printf and this String

Projects Programming
1

This is driving crazy. I want to print this string at I get garbage but Serial.print works fine.

  //////////////////////////////////////////////////////////////////////////////////////////
                String   parse_L350_parameter(String L350status, String ParameterName) { 
//////////////////////////////////////////////////////////////////////////////////////////
                unsigned int StartPos = L350status.indexOf(ParameterName, 1);
                unsigned int ParamPos = L350status.indexOf("=",StartPos);
                unsigned int EndPos   = L350status.indexOf("\n",ParamPos+1);
                String       Parameter= L350status.substring(ParamPos+1, EndPos);
                Serial.printf("StartPos,ParamPos,EndPos %d %d %d Parameter=",StartPos,ParamPos,EndPos);Serial.println(Parameter);
                Serial.printf("Serial.printf = %s\n",Parameter);
                return Parameter;
                }

and this gives me the following:

StartPos,ParamPos,EndPos 711 730 752 Parameter=-0.000103521871239062
Serial.printf = \`⸮?

Thanks
Kurt

2

Maybe try:

Serial.printf("Serial.printf = %s\n", Parameter.c_str());
1 Like
3

Thanks. That thought just occurred to me shortly after I posted this. Sanity is restored.

1 Like
4

If I recall correctly, you can also try:
Serial.printf("Serial.printf = %S\n", Parameter);
(Capital 'S' for String type.)

5

Not sure about printf, for sprintf the capital 'S' is used when the char array is in PROGMEM.

6

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.