Initial Setup of DreamPlug
To setup the DreamPlug to boot from SD card, you have to change the uboot environment. This is done via a serial console connection provided by the necessary JTAG board for your DreamPlug 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 DreamPlug from here. Unrar the file "mhdreamplug-vxyz.rar" to get the 4GB image file "mhdreamplug-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.
Signaling of the IP starts about one minute after boot. Sequenze begins with blue LED opposite to green power LED going off, then each of the four numbers (delimited by a dot) will be signaled one by one via blue blinks of the LED next to the green power LED. The dot between the numbers will be signaled by a blink of the blue LED opposite to the power LED. Each number is signaled by blinking digit per digit. Each digit is represented by a short blue blink of the LED next to the power LED 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 sequenze is done, an the LED opposite to the power LED is constantly turned on blue again.
Example: IP 192.168.10.77 Legend: N = blue LED next to power LED, O = blue LED opposite to power LED, _ = LED is dark
Signal: Comment OOOO___N___N_N_N_N_N_N_N_N_N___N_N___O 192 ___N___N_N_N_N_N_N___N_N_N_N_N_N_N_N___O 168 ___N___N_N_N_N_N_N_N_N_N_N___O 10 ___N_N_N_N_N_N_N___N_N_N_N_N_N_N___OOOO 77
When Meteohub does not have a valid IP this will be signaled with three blinks shortly following each other.