Gumstix
A friend (Tyler, KB1HCY) recently dug out his old Gumstix single board computer and expressed a desire to see if it still worked. So, also being curious, I invited him and Pat Wilbur (KC2OXM) over to try it out at my place. For the record we’re using an unknown model of Gumstix with an Audiostix II daughterboard and an Ethernet daughterboard I’ve forgotten the name of. All are visible in the pictures.
First we tried powering it off Mini-USB. Upon connecting it to Gojira by USB cable we took note of some Green LEDs on the board that implied power. Not noticing any new devices on my Linux install, we first assumed it was dead. We then decided maybe the USB interface was not sufficient to power it (at this time we were just guessing, hadn’t yet found any documentation on this older Gumstix). So we connected a small barrel plug to it and used test clips to hook it up to my HP power supply, set for 5V. The LED got a bit brighter, and a USB device showed up. It was a USB networking system. We later determined the extra power had nothing to do with it, the Gumstix is just slow to start up. Though it did lead to some funny dances of connecting and disconnecting power sources trying to recreate the condition later, not realizing the system wouldn’t be ready immediately after power cycling! D’oh.
At this point we started searching for documentation with Google, after a while we stumbled on to this procedure. It worked, after a few ps/kill sessions to make Network Manager stop trying to auto-configure the USB interface. Once we had it up and running we started fighting with vi to edit the interfaces file so that the network jack (eth0 on the Gumstix) would properly start up and execute DHCP. After several failed attempts (the USBNet link seemed to fail within a few minutes), Pat suggested using cat to ‘paste’ the new file over the old one in one single burst.
His method was to use the command:
cat > /etc/network/interfaces
Which would overwrite the file with whatever was received through the STDIN. Great idea, so I took the original file, dumped via cat to the screen, in to gedit, and made the modifications. Then I logged back in over ssh and ran that command, so the system was all ready to accept the new file. Keeping in mind that file’s original configuration is what prompts USBNet to search for DHCP and is fairly essential to that link working at all, we almost bricked it, well I almost bricked it. As soon I started cat I instinctively typed CTRL+V instead of Gnome Terminal’s standard Paste shortcut SHIFT+INSERT. Instead of pasting our corrected file in place on the tiny computer, it sent the control character ^V, overwriting the entire file with that! I started panicking and quickly killed it. Knowing how unreliable USBNet had been thus far we were all dreading it dropping it at exactly that moment. It was a tense few seconds while I retyped the command and properly pasted the new file in. Immediately after that it did fail. Talk about close. Screwing that up would have meant some tricky soldering to gain access to the serial port on the Gumstix, or at least purchasing another board. However it worked out fine and on next boot the Gumstix sucessfully configured both of it’s interfaces (Ethernet and USBNet) over DHCP and we were able to play around with it for a while. All in all a successful evening, albeit tense at times.
And of course, I took photos:
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| Gumstix |