The Balloon Project

Welcome to the Balloon Website

Balloon is an Open hardware development board intended for use as a computing module in embedded devices, development projects or educational settings.

Balloon should be viewed as a versatile 'computer component'. Most projects need their own bit of hardware or IO. Balloon means you can concentrate on that part and add it on to the base Balloon. Balloon has the CPU, RAM, NOR and NAND Flash, serial, USB client/host/OTG, I2C, Compact Flash, IO header, buffered expansion bus, simple 8-bit bus, and a CPLD or FPGA. It is particularly suitable for battery-powered devices, wearable computing, low-power instrument monitoring, robotic control and university or corporate research needing physically small, lightweight (<30g), low-power(<1W), high-performance computing.

The board is designed so that unneeded parts can be left off and things still work, to keep costs and power consumption down. The possibilities are described under build options. Small batches of boards (30 or more) can be built to a given spec.

This site is a collaborative effort. We'd like to see a collection of Balloon add-on boards released under similar licenses, as well as co-operation on software and configuration. There is a Wiki to make it easy to add your experiences. Much of the most recent and uptodate info is in the wiki - take a look there for info. And a mailing list of course.

The design is licensed so that all schematic, logic and design details are publically available and anyone can build boards. However, for the project to be successful economies of scale are essential in the build process to keep board costs down. Thus people are strongly encouraged to join with other project members to concentrate build volumes, and not to make lots of slightly-different balloon-a-likes. For this reason the protel design files are not public - you will need to do your own layout to build a different version of the boards.

The design is not static and will continue to be developed to keep up with component availability and the features people want. The current version of Balloon is 3 which is being used by various institutions and companies. 3.0 is an updated version to the next-generation ARM CPU/SOC (PXA270) which has higher levels of integration so it is cheaper to build and has better functionality. Balloon 3.0 is as compatible as possible with the Balloon 2.05 series so expansion boards will continue to work. Keep an eye on the news for current status.

Balloon 3.0 Specification

Core Features

• Intel XScale PXA270 processor (max: 520Mhz)
• 128Mb Mobile SDRAM (max: 512MB)
• NOR flash ROM (max: 32MB)
• NAND-flash, including 16bit variants
• JTAG programmable ROM and PLD
• Real time clock
• Choice of FPGA or CPLD
• Mobile Scalable Link
• Single 5V Supply
• Small and Lightweight (113 x 56mm Typical weight: 20-30g)

I/O and Interfaces

• 10 GPIO
• 4 ADC inputs (10bit)
• LEDs & inputs for debugging
• Reset bus
• Stereo audio codec
• Touch screen interface
• LCD interface for STN & TFT displays
• Serial Interfaces
• USB host, slave and OTG ports
• MMC interface
• Docking connector
• 'Samosa' bus
• CompactFlash socket(s) (not hot-plug)
• Camera interface

Balloon 2.05 Specification

• Intel Strongarm SA1110, to 206MHz
• Rom, to 32Mbyte (really just trying to be boot rom)
• Ram, to 256MByte (64MByte without stacking)
• Nand-flash, to 2Gbit, including 16-bit interface variants.
• SmartMedia card, to whatever the limit is today
• Codec (16bit, 44KHz, stereo mic in & stereo line out)
• 2W per channel power amp (class D, so efficient)
• 3 serial ports (2 at 12V, one at 5V)
• Reset (including pushbutton) and power control.
• LCD interface for STN & TFT panels (including bias voltage generation, to +-28V, 100mA, resistor settable, software adjustable)
• LEDs & inputs for debug.
• Unique ID chip / Silicon serial number
• USB two slave ports (to attach to a PC) and 2 host ports (to attach peripherals) - including power control.
• CompactFlash socket (not hot-plug)
• Power supply takes 6-42V - ideal for automotive / battery / lab use OR...
• Single 5V supply (local supply voltages derived on-board)
• Software control of subsytem power supplies
• JTAG programmable for both Boot ROM and PLD
• Real Time Clock with connector for battery
• Whole address / data / control bus buffered and sent to docking connector on back of board.
• 103 x 56mm (credit card, extended by 1cm on long side)
• Weighs 20-30 grams in typical configurations

The board makes sense in 2 basic configurations - in single-sided-component mode, it's thinner, but you lose the buffered A/D buses, but keep the GPIO connectors, LCD connector and Audio stages. In double-sided mode, it's thicker but has the buffered busses, to allow it to plug into other boards, and/or the CF socket.

Getting One

Boards are being built in quantity by iEndian.com, a new start-up to manage balloon development and production. Boards are in stock there now.

webmaster: Wookey