Monday, January 25, 2010

Serial Port Setup in BeagleBoard

[Italics shows the actual commands]

After the Memory Card has been formatted and Angstrom OS files loaded , it is time to configure the Serial Port connection to your Laptop.

We need Serial-to-USB Adapter like the one using PL-2303 from Prolific Inc. In latest Linux distribution the driver of PL-2303 is provided and is loaded automatically on detecting the device.
Also we need a 10 pin Flat Cable to connect to 10 pin box Serial connector on the BeagleBoard.
To connect the 10 pin Flat Cable to Serial-USB Adapter we made a small PCB.

The connection are as follows -
BeagleBoard                     Serial Port Connector
Pin No – 2(RxD)                Pin No - 3(TxD)
Pin No – 3 (TxD)               Pin No - 2(RxD)
Pin No – 5(Gnd)                Pin No - 5(Gnd)

The PCB for connecting 10-pin connector to DB9 and the powered USB device arrangement which didn't work :(

After connecting the USB connector of Serial-USB Adapter in your Laptop , it is time to configure the virtual serial port.

[root@shubham shubham]# dmesg
pl2303 ttyUSB1: pl2303 converter now disconnected from ttyUSB1

This will give a long output and among them try to find the line which has the mention of PL2303. This tells us that the name of serial device is ttyUSB1 .

Use a serial port utility like Minicom (you can install that on Fedora system using Yum )
Open the Serial Port Setup

[root@shubham shubham]# minicom -s

| Filenames and paths    |
| File transfer protocols |
| Serial port setup          |
| Modem and dialing      |
| Screen and keyboard   |
| Save setup as dfl          |
| Save setup as..             |
| Exit                               |
| Exit from Minicom       |

Select option Serial Port Setup by using cursor.

Change the name of Serial port device to represent /dev/ttyUSB1,which was found using dmesg command. Make the other setting of Baud Rate, number of bits, one error bit by setting it to 115200 8N1

| A - Serial Device : /dev/ttyUSB1                      |
| B - Lockfile Location : /var/lock                      |
| C - Callin Program :                                         |
| D - Callout Program :                                       |
| E - Bps/Par/Bits : 115200 8N1                         |
| F - Hardware Flow Control : No                     |
| G - Software Flow Control : No                       |
|                                                                           |
| Change which setting?                                     |

Save these settings and exit.
Now Launch the Minicom using

[root@shubham shubham]# minicom

Serial Connection to BeagleBoard

Now power up the BeagleBoard and you will see the Booting up:-

Notes :-

  1. We observed that USB OTG does not always supply sufficient power so if the booting fails again and again . Try using DC power using Barrel Connector. But make sure it is exactly 5V.

  2. An indication of BeagleBoard being booted properly is that LEDs USR0 and USR1 keeps glowing intermittently.


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