Lair Of The Multimedia Guru

August 2, 2019

Amazon price errors

I just managed to order 15 euro worth of office stuff on amazon for 1 euro 22 cent. And together with buying my first 30 euro giftcard i should theoretically get a 5 euro coupon. So if that worked that means amazon will pay me 3 euro 78 cent for doing probably 2 separate free deliveries of things to me.
2 Deliveries because mysteriously it was out of stock so the gift card would come separate and first i assume.
Not as cool as that case where amazon recently managed to sell 13k USD equipment for less than 100, i wish i knew about that one in time :(
But still cool.

PS: The price already changed back to normal by the time iam writing this

Filed under: Off Topic — Michael @ 8:45

May 23, 2019

EU elections 2019

A new EU parliament is being elected currently, (23-26 may depending on country). If you live in the EU and care about your future, you should vote.
Its only 1 in about 380 million potential votes. Not much effect you have but if you do not go then you have 0 and cant complain next time the EU passes a law that “noone” wanted.
You can check on saveyourinternet how your countries representatives and parties voted on the copyright directive. Looking at how politicians actually voted is better than listening and believing what they claim they will before an election.
Some related street Photography:

Leaning on a tree our nationalist party is campaigning.


A few streets onward, our greens are campaigning in the park with a picture of a tank.


Right Nationalist Party (FPÖ) giving out Chocolate and Flyers. Yeah they gave me some too as i passed by after taking this picture.


Right Conservative Party (ÖVP) posing for someone else taking pictures. I took one too.

Where are the greens, small left parties and our sozial democrats (SPÖ) ? I dont know, i didnt pass by any. I saw some campaign posters for the sozial democrats but forgot to take a picture, they IIRC called people to go to the election on it.

And some days later …

A vandalized campaign poster of the FPÖ. I think that was after a video was made public showing them discussing with russian oligarchs (or claimed to be oligarchs) about funneling money and contracts to them in exchange for buying a newspaper and manipulating elections with it. And also discussing how to move money around behind the “Rechnungshof”. Looks almost like a russian bear ripped the poster off.

Update 2019-05-24:

Finally run accross a SPÖ poster. Still no trace of NEOS and the other small parties but i also found a


Fox. It was faster than my camera liked.

Filed under: Uncategorized — Michael @ 11:30

April 13, 2019

Photography

Some random pictures from my cameras sd card in chronological order (this is from end 2017)


Dont focus on me.


Dont step on me.


You shall not pass.

Filed under: Nature,Off Topic,Pictures — Michael @ 12:00

February 25, 2019

Copyright EU #6

On the 20th February the EU governments approved the current text, the way i understand it, it next goes back to the EU parliament for a final vote.
I ve found a quick summary of the problem with article 13 on youtube.
There are also numerous articles from the EFF and basically everyone else about the directive. So whichever news site/creator you like, chances are (s)he said something about it. The really interesting or should i say scary part is, ive yet to find someone except the politicians and lobbyists who push this to be in favor of this change.
So who will the winners and loosers of this likely be if it passes ?
The one thing that seems obvious is that if any variant of this pass, getting some content from a creator to a consumer will involve more laws, more regulations and more risk for intermediaries. Thus it will, in two words, cost more. Increasing cost for consumers, decreasing income for creators. And consuming more paper for the extra bureaucracy. Likely less diverse sharing platforms, less diverse content. It appears that almost everyone would be loosing a bit if this passes …
Btw i almost forgot, the next EU parliament election are very soon. If you live in the EU please vote, no matter if you like or dislike the EU copyright directive, vote for the party you believe is best.
If you want to know how the members of your parties voted about the copyright directive, thats available on https://saveyourinternet.eu/act/ (currently its the previous vote, iam not sure how this page will change after the final vote).

Filed under: Uncategorized — Michael @ 20:29

February 13, 2019

Copyright EU #5

Today the EU Parliament and council negotiators have agreed on a final Text. Next IIUC are the final votes of the various institutions.
I have not had the chance to fully read the text, just 1 page that was quoted on Twitter. So iam not in a position to really say what it means but what ive heared earlier today does not sound reassuring. Nor does it feel great that the public (like for example me) seems to basically depend on “leaks” from the law makers to know what is going on. Whats in the text, and so on. The EU should make their proposed texts and _ALL_ discussions fully uncut and un-delayed public.

Some sources of information: (the full text of the proposed directive might appear on these maybe)

Julia Redas Blog
Julia Redas Twitter
A short video about the situation yesterday
WBS (German lawyer) Discussing the yesterdays situation

Filed under: Uncategorized — Michael @ 22:04

January 13, 2019

Another ARM failure

A few days ago when i wanted to run some benchmarks on my cubox, i run into some odd errors, investigation led to the micro sd card. There where several bad sectors that could not be read anymore.
Thats the first time ive myself seen a sandisk micro sd fail. ive seen transcend (really quickly) and kingston (not so quick) fails but no sandisk or samsung till now.
Another point for FATE, another disk it won against…
But how badly damaged is the sd card? ive run ddrescue on it for a few days:

# ddrescue -r 5 /dev/sdd backups/cubox-2019-01-07 backups/cubox-2019-01-07.log

GNU ddrescue 1.17
Press Ctrl-C to interrupt
Initial status (read from logfile)
rescued: 7947 MB, errsize: 493 kB, errors: 217
Current status
rescued: 7947 MB, errsize: 254 kB, current rate: 0 B/s
ipos: 7389 MB, errors: 48, average rate: 122 B/s
opos: 7389 MB, time since last successful read: 1.5 m
Finished
# ddrescue -r 20 /dev/sdd backups/cubox-2019-01-07 backups/cubox-2019-01-07.log

GNU ddrescue 1.17
Press Ctrl-C to interrupt
Initial status (read from logfile)
rescued: 7947 MB, errsize: 254 kB, errors: 48
Current status
rescued: 7948 MB, errsize: 193 kB, current rate: 0 B/s
ipos: 7389 MB, errors: 37, average rate: 10 B/s
opos: 7389 MB, time since last successful read: 7.2 m
Finished
# ddrescue -r 40 /dev/sdd backups/cubox-2019-01-07 backups/cubox-2019-01-07.log

GNU ddrescue 1.17
Press Ctrl-C to interrupt
Initial status (read from logfile)
rescued: 7948 MB, errsize: 193 kB, errors: 37
Current status
rescued: 7948 MB, errsize: 176 kB, current rate: 0 B/s
ipos: 7389 MB, errors: 36, average rate: 1 B/s
opos: 7389 MB, time since last successful read: 41.4 m
Finished
# ddrescue -r 80 /dev/sdd backups/cubox-2019-01-07 backups/cubox-2019-01-07.log

GNU ddrescue 1.17
Press Ctrl-C to interrupt
Initial status (read from logfile)
rescued: 7948 MB, errsize: 176 kB, errors: 36
Current status
rescued: 7948 MB, errsize: 172 kB, current rate: 0 B/s
ipos: 7389 MB, errors: 35, average rate: 0 B/s
opos: 7389 MB, time since last successful read: 4.7 h
Finished
# ddrescue -r 160 /dev/sdd backups/cubox-2019-01-07 backups/cubox-2019-01-07.log

GNU ddrescue 1.17
Press Ctrl-C to interrupt
Initial status (read from logfile)
rescued: 7948 MB, errsize: 172 kB, errors: 35
Current status
rescued: 7948 MB, errsize: 163 kB, current rate: 0 B/s
ipos: 7389 MB, errors: 33, average rate: 0 B/s
opos: 7389 MB, time since last successful read: 41.7 m
Finished
# time ddrescue -r 320 /dev/sdd backups/cubox-2019-01-07 backups/cubox-2019-01-07.log

GNU ddrescue 1.17
Press Ctrl-C to interrupt
Initial status (read from logfile)
rescued: 7948 MB, errsize: 163 kB, errors: 33
Current status
rescued: 7948 MB, errsize: 151 kB, current rate: 0 B/s
ipos: 7389 MB, errors: 30, average rate: 0 B/s
opos: 7389 MB, time since last successful read: 4.7 h
Finished

real 1119m16.116s
user 0m1.274s
sys 0m3.877s
# time ddrescue -r 640 /dev/sdd backups/cubox-2019-01-07 backups/cubox-2019-01-07.log

GNU ddrescue 1.17
Press Ctrl-C to interrupt
Initial status (read from logfile)
rescued: 7948 MB, errsize: 151 kB, errors: 30
Current status
rescued: 7948 MB, errsize: 147 kB, current rate: 0 B/s
ipos: 4393 MB, errors: 30, average rate: 0 B/s
opos: 4393 MB, time since last successful read: 15.1 h
Retrying bad sectors… Retry 375^C
Interrupted by user

real 1236m21.926s
user 0m1.383s
sys 0m4.204s

Its interesting to note that even after quite some time there are still damaged sectors which can be recovered. It was just myself loosing patience that made me stop it. Also i have a backup somewhere IIRC so this recovery was just out of curiosity. And maybe ill play more with this card in the future to see if theres anything that can be done to improve recovery.

Hopefully ill have the cubox with a new sd card up and running fate soon again … (should be quite trivial)

Filed under: FFmpeg,Hardware — Michael @ 1:21

November 4, 2018

Silencing an oil-filled radiator

The way oil radiators work is that the oil inside is heated by electricity flowing through some resistive heating element. The heated up oil then raises due to lower density and that way circulates in the radiator which then gets hot and heats the air.
Noise is produced by either mechanical thermostats or relays, so every time the set temperature is exceeded by some fixed amount some mechanical switch or relay switches which makes a click. That can be annoying if one tries to use a device like this in an otherwise silent bed room.
The Device:

To get it open one has to remove 2 screws and slide teh front down:

The top can be removed too after that and after removing the handle.

Three more screws later the next front layer can be taken off, that is as much as we need to disassemble to access all parts we need to access:

Removing the lower board is trivial, just remove screws and disconnect cables:

Next the 2 noisy relays are desoldered:

To replace the relays 2 solid state relays from ali express are added, they are rated at several times the needed current (i expected the rating to be exaggerated when i ordered and wanted to make sure they arent underrated but it seems the seller actually was honest with the rating). Careful attention is also paid to their heat-sinking requirement (which is none at the currents they would be used with).

And a quick tests shows they are working fine and also have a pretty red led indicating that they are on:
btw, they are lacking their top cover because the heater could not be closed with it on, and it serves no purpose in this case

And now i have a silent electric oil heater radiator thing … click …WTF
Was there some part expanding from the heat and making a noise ? something on the 2nd board i didnt look at ?
I had it already reassembled and had to disassemble it again to trace where that came from. The radiator is rated for 2000W, one circuit 700 W or so and the other the rest to get to 2000W. It contains a fixed mechanical thermostat that disables both heating elements in case of overheat. and the 1300W heater has its own mechanical thermostat which disables just it at 85°C. The surprising thing here (to me) was that 85°C is easily exceeded by the 700W element alone. So the heater rating of 2000W is misleading at best because the heater under normal conditions will only heat with the 700W element continuously. The 2000W will just be used for a short period. After learning about that ive checked the shop where it was bought long ago and looking at heaters rated at 700W (which they have too and which are smaller) one quickly finds customer complaints that the 700W units switch off and are unable to sustain heating at 700W. This is Europa not China :( I did not expect to find this …
Ok back to the silencing, the solution here is in fact very simple. As the 2000W and 1300W modes are fake and only sustain 700W anyway and i have to assume for a good reason. The solution is to simply disable the 1300W part.

With that change the radiator is now actually silent and also looks cooler with the relay led shining through the front. Looking at the images i regret a bit that i hadnt thought about replacing the front by a transparent polycarbonate window. it would have looked cooler ;)

Filed under: Electronics,Off Topic — Michael @ 23:04

October 6, 2018

Pandaboard 5v power supply

A few days ago i noticed that my panda-board died. This is one of the 2 ARM systems on fate.ffmpeg.org.
Resetting or unplugging and re-plugging did not help. Replacing the power supply with a random 5v supply made it come back to life.
The failed power supply is a HNP-24-050 “HN Power Germany”. This is now probably the 3rd or 4th failed power supply for my panda board. The one its running on currently is a random one from ali-express. I must say iam really disappointed by the trash that some german electronic shops sell. All the failed power supplies where bought from germany, not china. The failed supply still produces 5v but when subjected to the slightest load its output collapses to 0, even 200mA is too much.
Ive read on the net that some digikey supply is recommended but both part numbers i found are marked obsolete.
Anyone has any recommendations ? I am not too positive that the 2€ +free shipping supply its running on currently will last very long.
I know i can just run it off a brand name ATX supply or a bench supply but that is a bit inconvenient.
Also if anyone wants to add more ARM hardware to fate.ffmpeg.org, so we have a bit more redundancy, thats certainly welcome

Filed under: FFmpeg,Hardware — Michael @ 23:41

September 20, 2018

Testing high voltages

The chinese negative ion generator i used in 3d-printer-particles-air-pollution made me a bit curious about what voltage it outputs. The page from the seller mentions several different values, 2-5kv, 5-8kv, 5kv and other things. So one wonders what it actually is. This sadly cannot be directly tested by just using a normal DMM as its a bit outside the supported voltage range of the average DMM. High voltage probes for DMMs exist but even chinese ones seem to cost at least ~70€ and i wouldn’t trust them safety wise. So lets make one for 1€ which we can trust to be unsafe.
We start out with a inappropriate high voltage probe enclosure, which we disassemble and remove the unneeded parts:

The innards of our HV probe is simply a 90MΩ resistor, which will together with the internal 10MΩ resistance of the DMM form a 10:1 voltage divider, extending its input range.

Lets try:

1470V, hmm
Checking what output saftey resistance this device uses:

It seems its something around 20MΩ, maybe 2 10MΩ resistors ? Its potted so no easy way to tell exactly. But this changes our output voltage estimate as now our probe effectively is 110MΩ instead of 90MΩ. That raises it to 1764V, but it still feels a bit lowish to me. Also the 120MΩ to ground would draw 15uA, which could pull the voltage down by an unknown amount. This ionizer thing after all is not intended for producing any current.
To test for this we can use a higher value resistor. I do have a 1GΩ resistor (though it cost more than 1€), with it we get:

Aha, 4270V, so the 15uA does in deed quite significantly pull the voltage down. Now with 1GΩ we still pull 4uA here so this is likely still a too low estimate. Sadly i do not have a higher value resistor ATM.
What remains is to check that the 2 HV probe setups actually work at all, we must test this as we cannot be sure the DMM behaves as expected in this setup.

Both produce expected values at a 1kV test input, the voltage appears to be slightly below 1kV though.

at a 500V test input the value matches much better indicating that indeed the 1kV test output seems lowish

disclaimer: high voltage is dangerous, do not play with it or replicate anything described above. If you do anyway you do so at your own risk.

Filed under: Electronics,Off Topic — Michael @ 10:39

September 10, 2018

Copyright EU #4

In 2 days (on 2018.09.12) The next vote on the copyright directive in the EU Parliament will occur.
Resources about the draft, which IIUC will be voted on are available on https://www.saveyourinternet.eu/resources/. If you live in the EU and feel that this proposal is bad you can use https://saveyourinternet.eu/ to contact your representatives.
There are also 252 proposed amendments, iam not sure these will be voted on or not (i thought they would but the timeline seems too tight to really do that).
Also there will be EU parliament elections in a few months. If you live in the EU and care about this, check how the parties voted on this directive and other directives that may affect you before you vote on who you want in parliament. Politicians of all parties are very dishonest, only by looking at past actions can one with any accuracy predict what they will actually represent. No politician would ever say they intend to vote in a way that the audience of the moment dislikes.

Filed under: Uncategorized — Michael @ 18:04
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