Category Archives: hardware

Data Recovery: SD, ddrescue and Android

All things come to an end at some point, so do uSD cards. And they tend to do that just about the time you normally LEAST expect them to.
Anyways, at my country house, away from the noise of the big city I had a cheap cellphone tethering internets over an OpenVPN connection. The operator does not offer proper external IP service, so I have to run an OpenVPN connection to have access to surveillance.
I have a bunch of cams here and there, mostly watching after these guys:

The cellphone itself runs a rooted android and a debian chroot with OpenVPN off an SD card. The SD card died this weekend and at some point I realised that I don’t have a recent backup. It was no big deal, just a debian rootfs + a bunch of config files for OpenVPN, but since I spent a while then and now perfecting configs and tuning OpenVPN for performance over the celluar network those weren’t backed up. Ooops.

Anyways, this note talks about data recovery from such an SD card and the common pitfalls.

Continue reading Data Recovery: SD, ddrescue and Android

Flying Bear P902: Fixing extruder dust problem

I recently got myself a new toy, so to speak. It’s a brand new Flying Bear P902 3d printer. For it’s price (~300$) it’s an awesome machine and is way better made than my old 2nd gen Solidoodle. So I’ll be posting a series of hacks that I had to do to work comfortably with it and this is the first post in series, starting with this one.

Continue reading Flying Bear P902: Fixing extruder dust problem

Tablet guts necromancered into a fancy SBC

It’s been a hell of a summer with loads of work at my dull dayjob so that I’ve almost forgotten about everything including this very blog. However once the hell cooled down a little bit I found myself with a few spare days and my usual itch to tinker for a little bit with something. It happened I also needed another linux single-board computer to do some dull geeky stuff. Instead of ordering one from aliexpress once again I dived into the junk and found this little dead piece of hardware:

IMG_2598

Continue reading Tablet guts necromancered into a fancy SBC

Fun with PCB stencils

When you’re assembling just one or two pieces of your homebrew electronic stuff you never think about how fast the process is. But then comes a moment when you need to assemble 10 or 15 pieces, and it’s still cheaper to do it at home. The process quickly becomes dull as hell, and the brain starts to think of all the ways to speed up the process.

IMG_2531 Continue reading Fun with PCB stencils

D-Link DNS-327L NAS now mainlined

Achievement

Yep, something like that. Despite huge amounts of rush at work these days I managed to push both patches into mainline linux, so starting from 4.1 and on you can just grab kernel from kernel.org, compile and boot it on the NAS (Yappee!!)

Just make sure you disable cpuidle ‘deep idle’ state. It causes NAS to hang once every few hours and is likely a problem with either hardware or the bootloader (I’m still too lazy to try out mainline u-boot)

echo 1 > /sys/devices/system/cpu/cpu0/cpuidle/state1/disable

//Template for that achivement logo borrowed from here

Pssst, dude! Wanna some secondhand chips?

There are many wonders in electronics land. Even more await an engineer that stocks up at aliexpress to save a bit on his hobbies. Well, I needed a few RTC chips for some prototype hardware, so I picked DS1307. As usual, placed an order at aliexpress. once in a while shit happens .

No, this time they didn’t write ‘sex toy – 3$” on the customs declaration sticker, as they did on a parcel with a dozen of TRIACs a few weeks ago (Or, did I use TRIACs wrong my whole life! Should have asked them for instructions!)

Anyways this time I received some second-hand chips. Packed in a plastic tube, no flux whatsoever, but small solder blobbies are all over the pins. Without unpacking, I’ve made a few pics. Sorry for the quality, but I put my USB microscope somewhere far and my usual camera doesn’t handle focusing on something that close well.

IMG_2508

Continue reading Pssst, dude! Wanna some secondhand chips?