BeagleBone Black Serial

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Revision as of 09:10, 3 December 2020 by Jshankar (Talk | contribs) (Serial Port Settings)

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BeagleBone Black Serial

Serial console is basically a remote terminal for the BeagleBone board. This way we can execute shell commands on BeagleBone board from our PC or laptop, and see its output. It is also useful when there are problems with the Linux installation on our board. To do so, we will need two things:

  1. Special cable for serial console, to connect our board to the PC (USB to Serial UART TTL 3.3v serial cable).
  2. Special software, to be able to manipulate the board shell via the cable.
    minicom, kermit, gtkterm, PuTTY, etc.

The cable connects to a serial UART on the BeagleBone board. With our Beagle board powered using a regular USB 5 V supply, connect the cable as described in the following table:

Function FTDI Cable BeagleBone
Ground Black GND wire Pin 1 J1 Header GND
TX→RX Orange transmit wire Pin 4 J1 Header RXD
RX←TX Yellow receive wire Pin 5 J1 Header TXD

Figure: BBB Serial Port (J1 header)
Bbb serial port j1 header.png

So first of all let’s go ahead and connect our board’s serial port to the PC’s USB port with our TTL-to-USB cable. Now that cable is connected to the board and to the PC, you should see that the ​ /dev/ttyUSB0 file appeared (you can also check ​ dmesg​ and ​ lsusb​ output to be sure it’s an FTDI cable, and not some other device):

$ ls -l /dev/ttyUSB*

You should see that ​ /dev/ttyUSB0 ​ file is in ​ dialout​ group. Let’s add current user to the dialout​ group, so that we can use serial console without root privileges:

$ sudo usermod -a -G dialout $USER

Logout/login in your OS (Ubuntu).
Check if your user is in ​ dialout​ group now:

$ id | grep dialout

Serial Port Settings

Baud 115200
Bits 8
Parity N
Stop Bits 1
Handshake None