Error with this function Serial.println("!!!");

[andreimo]

When you set this Serial.println("!!!"); function in your code.
Receive error:
avrdude: stk500v2_ReceiveMessage(): timeout
Solution:
don use more that "!!!" in Serial.print;

[matthijskooijman]

IIRC !!! is some escape sequence in the bootloader, not sure if this can be fixed.

Note that '!!!' is not the same as "!!!". '' indicates a single character, not a string (and possibly '!!!' is translated to a three or four byte integer, which is still different from a string...).

[ffissore]

@cmaglie is this a dup of #392 ?

[cmaglie]

Yes, that was a know bug in the Mega bootloader, you can workaround by removing the triple "!!!" or if you really need it, by updating the bootloader with the new one.

C