What is this "// send terminating byte (ESC)" in the code?

[stasiana2]

In FreematicsONE.cpp, there is:

Code: Select all

        // send terminating byte (ESC)
        if (version != 10) {
                SPI.transfer(0x1B);
                digitalWrite(SPI_PIN_CS, HIGH);
        } else {
                digitalWrite(SPI_PIN_CS, HIGH);
        }

What is this terminating byte business and why is it needed only if the OBDUART version is 10?

[stanley]

The newer firmware (ver 1.1) requires an terminating byte of ESC.