Tuesday, 28 May 2013

Raspberry-Pi For Dummies PDF Sampler

Raspberry-Pi-For-Dummies-PDF-Sampler available as an online or downloadable PDF.

Full version available from amazon.
Raspberry Pi For Dummies (For Dummies (Computers))

Accelerated Desktop - Weston/Wayland

Interesting post about an accelerated desktop. Confused about why it has two names. However a step in the right direction. Sounds like its still at the early adopter stage. Its not a fully accelerated desktop but looks like it farms out a lot of layout related stuff the the GPU. The video shows fancy fading in and out, I hope it will deliver better performance to a standard desktop scheme too.

See: wayland-on-raspberry-pi

PiCloner and PIWriter for Mac

Using PICloner and PiWriter on my Mac book air. Easier and less stressful than "dd". Now having some issues but I suspect the Mac Book is sleeping as it is taking too long. I have disabled the sleep when power connected. Lets see if this does the job.

Friday, 15 March 2013

Minor health check and disk repairs

So, you have removed power before shutting down. The disk could be a little confused. Use "fsck" to fix problems. However this should not be done when the disk is mounted. DO NOT TRY IT. However there is a way to check the FS on boot. There is no need to create a second system disk. Run the check by create a file "/forcefsck" and then reboot. This will cause a disk check to run on startup and minor problems will be repaired. To create the file you may need to use the command "sudo touch /forcefsck". Reboot using "sudo shutdown -r now". (this may have an alias but I only know the long hand version of reboot.) You should see an ASCII progress bar during boot and the file will be removed. If the progress bar is missing and the file still survives you have probably typed it wrong.

Monday, 7 January 2013

Bigtrack one day it will be finished.

One day I will finnish this bigtrack project. The ultrasonic sensor is triggered from a 555 through a transistor to get the correct mark space ratio. The ultrasonic output is RC filtered and a then goes through a PCF8591 ADC to I2C. This means some loss of accuracy but I can read the distance asynchronously. I have also connected the battery supply via a 10v Zena to the ADC so that I get an accurate battery monitor. This is important as I do not want to discharge the 11.7v LiPo battery. (Will also add a LiPo battery alarm.) The GPS is a Garmin Geko 301 that connect to the serial port using very cheap max 232 level shifter powered of the Raspberry Pi's 3v3. The Geko has a compass (and barometer?). There are a couple of DC DC converters and voltage regulators. The PCF8591 is running of a supply that could also be used for the GPS. I have not yet connected the GPS supply so I am using the standard batteries. Hope to use some sort of web based interface for remote control. I have also used a PS3 webcam but the streaming is very delayed. I need to find a better streamer with less lag.