readBytesUntil() using a negative termination character

[jmz]

I'm sending serial commands from processing to an arduino teensy via xbee and want to have it read 15 different values/bytes at a time. Negative (signed) integers are transferred serially without a problem, however when I try to use a negative integer as a termination value for the buffer, it never recognizes it as such. 

All values I'm sending are positive integers, so I want to keep all 128 values reserved for commands and not have to worry about one being the termination character. Is there something I'm missing, or is it just not possible to have a negative integer as that termination character??

For example:
readBytesUntil(-10, buff, BUFF_SIZE);

Thanks in advance

[adafruit_support_bill]

Are you transmitting data as ASCII strings? ReadBytesUntil() is testing for a character byte value, not the value of an integer string.

[pylon]

Your code should work although I would never use a negative integer literal as the value for a character but use a hex value (0xf6 in your case) instead. Please note that an integer is two bytes (in Arduino terms) and a character is one byte. This may be the reason for your code to fail, if the PC sends integers (may be two or even four bytes) and the Arduino expects bytes. Try to define exactly what byte sequence your PC is sending.