Saturday, March 14, 2009
OK - So it's not the prettiest setup nor the cleanest setup but it works for testing (grin).
If you look closely (clicking on the picture will give you an enlarged view) you will see the different components which comprise my development system.
On the left is the DVI-D to RGB converter which allows viewing the video output from the Overo/Summit system on a regular LCD display. This adaptor is only needed if you have an older monitor that does not have a DVI-D input. Most current LCD HDTV sets do so that could double as a monitor too.
To the right is the actual Overo Earth board installed on a Summit expansion board. Installed in the MicroSD slot is a class-6 8-Gigabyte Micro-SDHC card which contains the uboot loader, Linux 2.26.29-rc2 kernel and the Linux filesystem. Even with all of that there is still over 7-gigs of free space left on the card.
Also in the picture is a Transend 2.5" SATA-2 64-Gig Solid-State Drive connected through a SATA-2 to USB-2 adapter to a Targus 2.0 USB Hub. Since the USB ports on the Summit expansion board are High-Speed USB-2 ONLY you need a 2.0 USB hub capable of handling the lower speed USB devices. For those of you who like technical specifications I have been able to read data from teh SS-Drive at about 20-Megabytes per second, write speed is much slower at around 2-Megabytes per second. Even though the write speed is slow by today's standards this is still very respectable given the size of the system.
Keyboard and Mouse input are handled by a Logitech Wireless Keyboard and Mouse and you can see the Wireless Keyboard/Mouse receiver connected to the USB HUB. The operating system loaded in the Overo's non-volatile flash memory already has the drivers needed to use this combo setup.
Ethernet connectivity is handled by a Hawking 10/100 Ethernet to USB adapter and the little device plugged into port three (second from the right on the HUB) is a Bluetooth transceiver. Now - the Hawking adapter shown here is a discontinued device but there have been reports of the Linksys USB200M Ethernet/USB adapter working fine with the board.
Again I stress - the Overo does not have enough power supply to handle external USB devices so you MUST use a powered 2.0 USB HUB The Overo only has high-speed (480-mbit/sec) USB ports which will not work with slower 1.1 and 1.0 USB devices which is the reason for using a 2.0 USB HUB. Trying to power external USB devices from the Overo directly is the best way I can think of in turning this little power-house into a dead speck.
So - in a nutshell there is a 600-MHz ARM Cortex-8 based computer with 256-Megs of Low-Power DDR RAM, 256-Megs of Flash memory, 8-gigs of Micro-SDHC storage with 64-gigs of SS-Drive external Storage, Wireless Keyboard and Mouse input, 10/100 Full-Duplex Ethernet, Bluetooth, Stereo Audio Input and output along with HDMI (720P) capable video output in the current configuration. All of this and the total system draws about 12-Watts of power!
Not a bad little system by any current standard.
More to follow....
Posted by Gary N McKinney at 6:01 PM