I have moved your double post of the same question into this thread - don't double post. It just scatters potential answers and ties up resources without additional benefit.
Actually for valid JSON these single quotes must be substituted with double quotes.
In order to add (nested) double quotes to a double-quoted string in C/C++ you'd need to escape them like
char json[64] = "{ \"value\":\"0\", \"lat\":\"43.627125\", \"lon\":\"-79.360458\" };