LinkIt One Tutorials - #0 Fix That Pesky Serial Port!

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Anyone that has played with LinkIt One will doubtless have tried to use the Serial port to monitor output.

And failed.

Some clever ones amongst us may have resorted to FTDI cables (which do work) but there is a much easier solution.

void setup()
before you do anything else add the code below:

int i;

pinMode(13, OUTPUT);
for(i = 0; i < 20; i++)
digitalWrite(13, HIGH);
digitalWrite(13, LOW);

Basically this waits 10 seconds from startup, flashing the onboard LED merrily. While it is flashing, keep clicking on the Serial Monitor button in the Arduino IDE.
After a few seconds or so the Serial Monitor will open and as soon as the LED stops flashing you will see your serial data.

Always remember to close the Serial Monitor before you try to upload to the LinkIt One board or the upload will fail.

This may be a super small Instructable but it is an essential one to fix an issue that has affected me (and several others) since day one.

Please let me know in the comments section if the issue affects you.



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    6 Discussions


    The debug port is a hardware serial port attached to pins 0 and 1. This means you can connect an FTDI cable to those pins and see output from the moment the LinkIt One powers up.

    The modem port is a virtual port.


    3 years ago

    you know the 2nd comport on the LinkIT is the debug output right? you can use that for the serial monitor.

    3 replies

    Reply 3 years ago

    I mention FTDI cables in the second paragraph so yes I am fully aware of the Serial1 port on pins D0 and D1.

    Not everyone has a FTDI cable (or even serial ports on their computer these days). My method of inserting a delay at startup will work for everybody.


    Reply 3 years ago

    Sorry for being unclear, the board installs with 2 com ports on your PC, one is for programming and one is for debugging. you can use something like putty to always be open on the debug port. this can be done with no extra hardware or ftdi.


    Reply 3 years ago

    I am fully aware that D0 and D1 are Serial1.
    Not everyone has FTDI cables, this way works for everyone, not just those that develop on microcontrollers regularly.