Sunday, July 5, 2009

Peripherals for BeagleBoard

(left) Rev C BeagleBoard (right)

Important: The information provided here is based on "System Reference Manual" downloadable at

Components & Connections

Right side

5V Power Supply :

The supply must have a 2.1mm center hot connector with a 5.5mm outside diameter. A picture in right of the type of power supply will be used on the BeagleBoard.


USB OTG (On-The-Go) :

The main USB port on the BeagleBoard is a USB OTG (On-the-Go) port. It can be used as an OTG port or Client port. The main use is as a client port, as that is the mode that will supply the power needed to power the BeagleBoard.

NOTE: In order to use the OTG in the Host mode, the BeagleBoard must be powered from the DC supply.

RS232 :

In order to access the serial port of the BeagleBoard a flat cable is required to connect to a PC. The adapter will not plug directly into the PC and will require an external Female to Female twisted cable (Null Modem) in order to connect it to the PC. The ribbon cable is not supplied with the BeagleBoard but can be obtained from numerous sources.

Back Edge

S-Video :

An S-Video cable can be connected to the BeagleBoard and from there is can be connected to a TV or monitor that supports an S-Video input.


In order to connect the DVI-D output to a monitor, a HDMI to DVI-D cable is required.

Audio-In and -Out :

External Audio input devices, such as a powered microphone or the audio output of a PC or MP3 player, can be connected to the via a 3.5mm jack (Audio IN).

An external Audio output device, such as external stereo powered speakers, can be connected to the BeagleBoard via a 3.5mm jack (Audio OUT).

Front Edge


The SD/MMC connector can be used for Memory or SDIO type cards.

HS USB 2.0 Host Port (Rev C2 Only)

The Rev C2 Beagle is equipped with a USB Host only connector and can be used to support USB based devices. In order to connect multiple devices a Hub is required. The hub can be powered or un-powered if the total current on the devices connected to the hub do not exceed the available power from the DC source. If the board is powered from the OTG connector, then the power available from this port is extremely limited and will not be able to provide sufficient power to run most USB devices. It may be possible to run a USB keyboard or mouse, but that is about all it will have the power to supply. The USB Host port is HS only and does not support LS or FS devices without a hub.

Left Side

Expansion Header & LCD Expansion Headers (Rev C only) :

The expansion header is provided to allow a limited number of functions to be added to the board via the addition of a daughtercard.

There are two headers provided to allow access to the LCD signals on the Beagle. These headers are 2x10 headers with a spacing of .05 (1.27mm) pitch. How these connectors are used is determined by the design of the adapter board.


A JTAG emulator can be used for advanced debugging by connecting it to the JTAG header on the BeagleBoard. Only the 14pin version of the JTAG is supported and if a 20 pin version is needed, you will to contact your emulator supplier for the appropriate adapter.

DO NOT expose the JTAG header to 3.3V. It supports 1.8V only.

Indicator LEDs

There are four green indicators on the BeagleBoard. One of them, POWER, indicates that the main supply is active. The other three can be controlled by the software.


There are two buttons on the BeagleBoard; the RESET button when pressed will force a full board reset and the USER button which can be used by the SW for user interaction. If the user holds the USER button down while pressing and releasing the RESET button, the BeagleBoard will enter the ROM boot loader mode.