Contents - Raspberry PI Community Projects

▪ After writing the image to the SD card, verify that you can see the boot partition
when you insert the SD card into your computer. The partition should contain a
number of files, including start.elf and kernel.img. If you do not see these files on
the SD card, you have made an error writing the image file.
▪ If you are manually preparing your SD card on Linux or Mac OS using the dd
command, this operation will completely erase any existing data and partitions.
Make sure you write to the whole card (e.g. /dev/sdd) and not to an existing
partition (e.g. /dev/sdd1).
▪ If you have an sdcard that doesn't work with latest firmware, head over here
(http://www.raspberrypi.org/phpBB3/viewtopic.php?f=63&t=6093) .
▪ If you put the SD card into your PC in an attempt to write the R-Pi operating
system onto it, and the PC tells you the card is write-protected, even with the
write-protect tab in the correct, forward position, then you may have a faulty SDcard
rewriter. There's a common fault with many SD-card rewriters - The writeprotect
tab is detected by a very thin, narrow metal strip, that is part of a switch.
When the card is inserted, the write-protect tab is supposed to push the strip and
make/break the contact, as needed. Unfortunately, these strips have a habit of
getting stuck, because they are mounted in a thin plastic channel, and only need
to be deformed slightly sideways to get jammed.
Luckily, if you have this problem, most built-in card readers are easy to pull apart and
repair; some users have even reported succesfully unjamming the switch with a blast of
compressed air from a can into the SD-card slot without having to dismantle anything.
You may also be able to temporarily get round the problem by putting the write-protect
tab in a half-way position - this pushes on a different part of the strip and may break the
contact - it's worth trying a few, slightly different positions. You could also use a USB-
SD card adaptor, which are cheap to buy.
Networking
Ethernet connection is lost when a USB device is plugged in
This is often caused by inadequate power. Use a good power supply and a good power
cable. Some cheap cables that work with a cell phone, cannot fully power the R-Pi. Some
USB devices require a lot of power (>100 mA), so they must be used with a powered
USB hub. Some cheap USB hubs suck power from the Raspberry Pi even if a USB power
supply is connected. (More often than not, however, the reverse is true with cheap
hubs—the Pi draws just enough power backwards from the powered hub to
unsuccessfully attempt booting.)
There is an ongoing issue with the Ethernet connection being lost when low-speed
devices, such as mice or keyboards are connected via a powered USB hub. The simplest
way to solve this is to connect your mouse and keyboard directly into the 2 USB ports on
the R-Pi (assuming they draw less than 100 mA apiece).