It’s Aliiive!!!

Behold! The FrankenPiCam!

A few weeks before I saw a twitter post about someone taking a dremmel to a Model A+, I had the idea of cutting off the corner of a Model A, where the ethernet socket was missing anyway. I was inspired to make the flattest possible PiCam “mount” by Ben Heck’s video but only thought of the idea after seeing x-ray pictures of the revision 1 Model B. As the x-ray shot was not clear, I also looked at the gerbers. The evidence suggested no vital lines ran through the area so the next natural step was to test the theory.

First, I measured up the PiCam to see whether it would fit in the space available in the corner. At this point I considered if I wanted to cut into the USB mount holes.


Next, the flat ribbon connectors were depopulated off both the Model A and the PiCam board. As you can see I was a bit heavy handed and damaged the PiCam’s connector pads but the testpoints remained intact.


A quick test with RiscOS Pico showed my abysmal desoldering skills had not adversely affected the Model A so I proceeded to apply said dremmel to create space for the PiCam. The PiCam board itself was narrowed down to fit in without interfering with the remaining USB connector – visual inspection suggested I wouldn’t cut any vital signal lines. After some evening out to get the cuts to match, I applied a dab of super glue to hold the transplanted PiCam while I connected the boards with recycled resistor offcuts of around 10mm in length.


A final boot in Raspbian and hey presto – a flatcam. Note the orange wire running to the USB socket?  It looks like the 5V supply line runs through the corner I sliced apart.  In fact it is now a 3V3 line as hinted by the two wires soldered in place of the 3V3 regulator – an exercise in power efficiency, as I would like this FrankenPiCam to be battery driven through an LM2956.  I also bought some iPhone lenses off ebay to add some flexibility to the FOV. I was also going to add an Adafruit PiTFT for preview, but I realised that a CVBS screen will be faster because I can avoid using fbcp.  But more on that another time.


Fedora 16 Kernel Panic on Boot

In order to not mix my work setup with my home machine, I have a VM I work from ie. connect to VPN, check email etc.  I happen to use a Fedora install inside VirtualBox as opposed to VMware, but that’s irrelevant here.  Anyway, upon a recent “yum update” which included a kernel update, I began to see the following error upon boot :

Kernel panic upon bootup

A quick reboot into the previous kernel (I didn’t even have to hold SHIFT to get GRUBs menu) suggested the kernel was at fault.

GRUB Menu - Choosing previous kernel

But upon closer examination of the kernel and ramdisk images in /boot suggested something else :

Listing of kernels and ramdisk images in /boot

Strange that the initrd was so small. Running file suggested a gzip archive, but the image was much too small. A quick search led me to dracut being responsible for building the initrd, but running dracut itself failed. I didn’t capture that error message, but a quick “yum reinstall dracut” and re-run of dracut correctly created an initrd.