Initial Setup of SheevaPlug
To setup the SheevaPlug to boot from SD card, you have to change the uboot and uboot environment. This is done via a serial console connection and by a Linux PC.
Setup of SD card
You need a 4GB SLC SD card like Transcend TS4GSDHC150 or Integral Endurance 4GB. As you need a Linux Box for the previous step, only Linux way to write SD card is described. First step is to download the lates Meteohub SD card image for SheevaPlug from here. Unrar the file "mhplug-vxyz.rar" to get the 4GB image file "mhplug-vxyz.img". Please insert the SD card into your Linux box and check via "dmesg" what device the SD card has been mapped to. In the following example it has been mapped to "/dev/sdg"
# dmesg ... [4249761.783380] sd 7:0:0:3: [sdg] 7744512 512-byte logical blocks: (3.96 GB/3.69 GiB) [4249761.792619] sd 7:0:0:3: [sdg] Assuming drive cache: write through [4249761.806113] sd 7:0:0:3: [sdg] Assuming drive cache: write through [4249761.806116] sdg: sdg1 sdg2 sdg3
We are just looking for "sdg" and are not interested in the partitions recognized on the SD card (sdg1, sdg2, sdg3). The print out above tells that "/dev/sdg" is the target device. To make sure that the device ist not mounted by some background processes you should manually unmount all partitions by "umount". In the given example this will be
umount /dev/sdg1; umount /dev/sdg2; umount /dev/sdg3
When this throws errors about not mounted file systems that is fine. Don't worry. Now it is time to bring the Meteohub image onto the SD card. In the example above this will be done by
dd if=mhplug-vxyz.img of=/dev/sdg bs=1M
Please be careful with that command. When you choose the wrong "of=" target (i.e. your system drive) this will be overwritten without further notice and you will have to restore your Linux box! As dd has to transport 4GB of data to the SD card this will take a few minutes. When finished dd will report number of written blocks. If it reports that not all blocks could be written, something is wrong with your SD card (may be less than 4GB in size?).
About one minute after starting reboot Meteohub signals its IP by LED blinking, as it has no buzzer attached. On 1st generation SheevaPlugs the blue LED is used for blinking, newer Sheevas do have a orange LED instead.
Signaling of the IP start sabout one minute after boot. Sequenze begins with LED going off, then each of the four numbers (delimited by a dot) will be signaled one by one. The dot between the numbers will be signaled by a "H" (LED shines bright). Each number is signaled by blinking digit per digit. Each digit is represented by a "M" (LED shines medium dimmed) repeated as often as the digit tells us. The zero digit is signaled by ten blinks. After having done this for all digits of all numbers of the IP, the end is signaled by LED staying off a while like it started with. When Sequenze is done, the LED is constantly turned on again.
Example: IP 192.168.10.77 Legend: M = LED medium dimmed, H = LED shines bright, _ = LED is dark
Signal: Comment ___M___M_M_M_M_M_M_M_M_M___M_M___H 192 ___M___M_M_M_M_M_M___M_M_M_M_M_M_M_M___H 168 ___M___M_M_M_M_M_M_M_M_M_M___H 10 ___M_M_M_M_M_M_M___M_M_M_M_M_M_M___ 77
When Meteohub does not have a valid IP this will be signaled with three blinks shortly following each other.