GHI Electronics has announced a CPU module claimed to be the smallest and lowest-cost development system available for Microsoft's .NET Micro Framework (MF). Suitable for MP3 players, the $100 USBizi supports Microsoft's FAT (file allocation table) filesystem, and offers both USB and microSD storage expansion.
The USBizi measures just 2.2 by 2.2 inches, and is built around a 32-bit NXP LPC2388 microcontroller. This device, a block diagram of which is shown below, features a 16-bit/32-bit ARM7TDMI-S CPU core, along with 512KB of embedded high-speed flash memory and 96KB of RAM. A 128-bit wide memory interface and a "unique accelerator architecture" enable 32-bit code execution at a clock rate of up to 72MHz, according to NXP.
A block diagram of NXP's LPC2388 (Click to enlarge)
Unlike another LPC2388-based module sold by GHI, the Embedded Master, the USBizi does not make the microcontroller's 10/100 Ethernet interface available. As a consequence, however, the 16KB of RAM normally dedicated to Ethernet is available here as user memory. GHI says 40KB of the device's 96KB of RAM is available to the user. As for its flash, 100KB is available for the user, out of the 512KB total.
The rest of the LPC2388's flash storage is occupied by the USBizi's best feature, a complete, licensed installation of Microsoft's NET Micro Framework 2.5. Developers can use this to write managed code using C# "without having to deal with much complexity," claims GHI.
Unlike other .NET Micro Framework (.NET MF) devices (except for the Embedded Master mentioned above), the USBizi also supports FAT (file allocation table) filesystems, according to GHI. This allows access to files stored on a microSD card, for which the USBizi has a socket.
Alternatively, storage can be expanded by attaching USB memory devices to the USBizi's USB host port. This port is also able to support an optional Bluetooth dongle, thanks to GHI's exclusive .NET MF extensions, it says.
Because of its file access, the USBizi could be used to create an MP3 player or data logger, says GHI. Other potential uses cited are measurement and testing, robotics, GPS navigation, medical instrumentation, and industrial automation.
Additional hardware features offered by the USBizi include the following, according to GHI:
44 GPIOs
35 interrupt inputs
SPI (8/16bit)
I2C
4 x UART
2 CAN Channels
7 x 10-bit analog inputs (4 on Rev 2.x)
10-bit analog output
It's said an LCD display can be connected to the USBizi and controlled using either SPI or some of the many GPIOs available. Meanwhile, most signals provided by the device are multiplexed in order to offer more than one function for every pin, according to the company. While both the GHI drivers and .NET MF do some checking to make sure a user is not trying to use two functions on the same pin, developers should still be aware of the potential for conflict, warns GHI.
Finally, the USBizi has a claimed 10mA current consumption "with everything enabled," according to GHI. The RoHS-compliant device also has a wide operating range, from -40 to 85 deg. C.
A demonstration of the USBizi Source: GHI
Further information
The USBizi is available now for $100, including .NET MF 2.5. A version that includes .NET MF 3.0 will be available soon, says GHI.
More information may be available from the company's website, here.
