Hello,
The serial functions that we provide are described in detail in the Command Reference. Yes, that argument must be a character array. I do not really know what you mean by “for it to be properly picked up as a bitwise transmission”, but the fact is that if you call serial_send_blocking(temp, 10), it is going to interpret temp as a pointer to an array of 10 bytes and send whatever bytes it happens to find at that address. In the example code you provided, that is probably not what you intend.
I would start with something like this:
char buffer[9] = {'T','e','s','t',':',' ','0','0','\n'};
serial_send_blocking(buffer, 9);
This should send the message “Test: 00” plus a newline to the serial port.
Once that works, try adding
and you should get “Test: 03”.
If that works, I am sure you can figure out how to modify the code to print whatever integers you want, using similar math to what you are already putting in the arguments to print_long().
-Paul