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Jeremie Francois
872 followers -
An open-minded technophilic iconoclast driven by curiosity.
An open-minded technophilic iconoclast driven by curiosity.

872 followers
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A cheap "patch" antenna for wifi that works well!
To me, it looks like a fractal antenna (which I thought "more useful" for getting a wide range of frequency -- which proved not antinomic, see below!). Actually this looks like a Peano/Hilbert plane-filling curve (https://en.wikipedia.org/wiki/Space-filling_curve)
About fractal antennas: https://en.wikipedia.org/wiki/Fractal_antenna
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Failed reflow: all the flux was evaporated but the oven did not heat enough and the myriads of tiny little balls of solder did not fuse!
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During/after an upgrade from Ubuntu 14LTS to 16LTS: mysql-server-5.7 fatally depends on mysql-server-5.7. WTH?!
I tried to purge & rm -r everything in vain, no way I will install mysql on this server. I hate mysql server packaging.

root@service:/# apt-get install mysql-server-5.7
(...)
dpkg: des problèmes de dépendances empêchent la configuration de mysql-server :
**mysql-server dépend de mysql-server-5.7 ; cependant :
Le paquet mysql-server-5.7 n'est pas encore configuré.**
(...)
E: Sub-process /usr/bin/dpkg returned an error code (1)
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It was a long time I did not make something with #openscad (rendering is done with #povray). The UM3 spool holder is ridiculously placed ~2cm too low on the back of the printer, and big rolls of filaments rub on the table. Like, I mean, it almost looks like it was designed to create problems... for non-ultimaker filaments, or what? Also, the default holder system is quite convoluted, so it took me a couple of hours to make an openscad model of the male & female parts (with the help of the STL for the official spool holder https://www.youmagine.com/designs/ultimaker-3-spool-holder )
This one can hold the default spool holder or a good old M6 threaded rod for my late 2013 "spider spool holders" https://www.youtube.com/watch?v=tNVpsIQXVbE
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I love rsync/rdiff, they are probably the best way to keep efficient mirrors the unix way (now, ok, there is owncloud -- but try to recover from a catastrophic issue with owncloud!). I just found https://rclone.org/ and I am really impressed. I was looking for a backup "in the cloud"... And +rclone is "rsync for cloud storage". It seems to synchronize to about anything, its features are awesome, and its documentation is outstanding! Check eg. specifically for Amazon S3: https://rclone.org/s3/
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Found back the video of my first reflow ever. It was done with a 25€ inductive skiller heater, where the ugly gray solder paste morphs into a shiny metal. The heater is controlled by an Arduino, via a PID, but it was not working well because of the large inertia of the glass plate. I switched since to a T-962 oven: it offers a much better control and reproducibility, but less visibility, and I had to tune a bit the solder curve as it was not enough and did a poor job of melting the solder paste on the first try (I had a hard job finishing some of the components with a soldering iron).
We see how the hand-placed components settle in place thanks to the capillary action of the molten paste. Mesmerizing (as usual... but my own little magic this time, not yet another youtube video...oh, well, yep another one sorry!)
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I suddenly feel the need to expand my bullshit-o-meter by an order of magnitude. WTF?!! Probably the only factor that units the two companies is the dubious chance of succes! :D Curious to see if their super heavyweight BS press releases is going to help them get a solid funding to move on. blockchain? done. Asreriod mining? done? Todo next is time travel via blackholes.
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Bah, no surprise. Nobody seems capable of making safe stuff nowadays! Like: market it, then patch it when issues are discovered. Windows of opportunities open and close all the time for hackers (I wonder if there is a global database somewhere to track exploits, probably)
‪#Google Home devices have a few open doors ;)‬

‪“I was surprised to see so many ports open so I started to do some research and found that these devices have an undocumented (and amazingly unsecured) API”‬

https://jerrygamblin.com/2018/10/29/google-home-insecurity/
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Hand-placed "large" BGA is becoming too easy so I switch to trickier chips (a 153 ball eMMC at 0.5mm pitch, on the right of the second picture) :D Incredibly, it seems to work ..... as bad as with the automated builds of the contractor. More seriously, the eMMC chip is seen/listed by u-boot, but we keep getting "voltage select errors" when we try to use it or get information about it. We though it could have been that the "new" JEDEC ones were using the 5.1 protocol and not the 4.5 (end of life). It is told everywhere that the 5.X is backward-compatible with the older versions. Still, I made another board with an old 4.5 just to check. And no improvement. This is no good :/
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10/29/18
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This is not opensource but the tool is free to use, and quite playful and efficient to sketch/design/purchase an aluminum profile-based gantry, with the option to buy the parts at the end (which IS the business model). I am not sure if it would exports the bill of material though, and I did not even bother to check if the prices are correct.
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