With the code for sd2tpdd from GitHub, the compiler was issuing the warnings
below. I have gone through and corrected them and the compiler is now happy and
the randomness in the first 2 characters is less random. They are still garbage
characters but now they are nearly consistently the same garbage for a given
file.
For example, for 3 runs of the load/save of the same file, I got the following
first 2 bytes (hex)
5C 89
97 8A
5C 89
On a different file I got 1B 8A
The compiler warnings were:
184:33: warning: invalid conversion from 'char*' to 'byte* {aka unsigned
char*}' [-fpermissive]
92:6: note: initializing argument 1 of 'void clearBuffer(byte*, int)'
253:30: warning: ISO C++ forbids converting a string constant to 'char*'
[-Wwrite-strings]
379:28: warning: ISO C++ forbids converting a string constant to 'char*'
[-Wwrite-strings]
473:24: warning: ISO C++ forbids converting a string constant to 'char*'
[-Wwrite-strings]
498:24: warning: ISO C++ forbids converting a string constant to 'char*'
[-Wwrite-strings]
522:34: warning: ISO C++ forbids converting a string constant to 'char*'
[-Wwrite-strings]
The NULL character is still being appended to the end of the file…no luck so
far chasing that one down.
To help with those who can confirm that they have their board working fine, I
am using Arduino 1.8.10 for build and upload.
The GitHub page for the source I am using is
https://github.com/TangentDelta/SD2TPDD in case I am using the wrong one.
I have now tried my 2 slightly suspect AliExpress Arduino Mega clones and
various combinations of el cheapo SD card readers and shop bought ones. The
genuine Arduino Mega I ordered from arduino.cc arrived today so have swapped
out the clones for the genuine article and still no luck.
