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by lrhorer
Sun May 26, 2019 12:00 am
Forum: Advanced users
Topic: New Problem in chromium
Replies: 2
Views: 351

Re: New Problem in chromium

Hey! That fixed it. 'Great advice, and thanks a million.
by lrhorer
Sat May 25, 2019 12:18 pm
Forum: Advanced users
Topic: New Problem in chromium
Replies: 2
Views: 351

New Problem in chromium

I am having a weird screen issue that was not there before. I don't know why it was OK before, why it has popped up, or how to fix it. It most likely has to do with some issue I created while reducing the writes to disk in an attempt to extend the life of the SD card. Prior to this, the screen was p...
by lrhorer
Fri May 10, 2019 4:52 am
Forum: Advanced users
Topic: Seeking the illusive zero write
Replies: 14
Views: 812

Re: Seeking the illusive zero write

I still need to do some investigation into zram, but in the meantime, I have reduced the writes to the SD card tremendously. There are a few things that remain the highest write rate on the card: 1. Directory updates. In particular, even though the sub-directories are tmpfs mounts, the listing of se...
by lrhorer
Wed May 08, 2019 8:01 am
Forum: Advanced users
Topic: Seeking the illusive zero write
Replies: 14
Views: 812

Re: Seeking the illusive zero write

If you are going to enable `zram-config enable-ephemeral` make sure any settings or changes are done before reboot as it is ephemeral on each boot `sudo zram-config disable-ephemeral` and reboot will get you back to normal. If you use an overlayfs then its only the upper of the merge mount that is ...
by lrhorer
Wed May 08, 2019 7:53 am
Forum: Advanced users
Topic: Seeking the illusive zero write
Replies: 14
Views: 812

Re: Seeking the illusive zero write

Have you considered using a different OS? Tiny Core Linux runs entirely from RAM, and there is a Pi version . The OS is not the problem. Other than LXDE, I have pretty much eliminated all writes to the drive by the OS by mounting /var/log, /tmp, and /var/tmp on tmpfs. LXDE does some writes that I t...
by lrhorer
Wed May 08, 2019 7:47 am
Forum: Advanced users
Topic: Seeking the illusive zero write
Replies: 14
Views: 812

Re: Seeking the illusive zero write

Obviously, I need to dig more deeply into zram, however first I need to find out how chromium's footprint can be reduced. I have already made some inroads into the issue, reducing the footprint by over 17M through eliminating unnecessary files, such as the site blacklist (SafeBrowsing). Another 16M ...
by lrhorer
Sun Apr 28, 2019 12:11 am
Forum: Advanced users
Topic: Seeking the illusive zero write
Replies: 14
Views: 812

Re: Seeking the illusive zero write

Yes, but size and cost are the issues, plus even an SSD suffers from a limited number of writes, although much less so than an SD. There is only about 32mm of clearance between the USB ports and the side wall of the device. If someone makes an economical SSD that only sticks out about 32mm or so (li...
by lrhorer
Sat Apr 27, 2019 11:09 pm
Forum: Advanced users
Topic: Seeking the illusive zero write
Replies: 14
Views: 812

Seeking the illusive zero write

As well represented on the web, excessive writes to the SD card will shorten its life. I am creating an embedded application using the Raspberry Pi, and I definitely don't want a continuous stream of users complaining of dead units due to SD write failures. I believe I have undertaken the majority o...
by lrhorer
Sat Apr 27, 2019 9:53 pm
Forum: Advanced users
Topic: Startup quit working with tmpfs /var/log
Replies: 3
Views: 183

Re: Startup quit working with tmpfs /var/log

I got it working by putting the target in /home/pi/.config/lxsession/LXDE-pi/autostart. Why it quit working in the global configuration, I don't know.
by lrhorer
Sat Apr 27, 2019 8:39 am
Forum: Advanced users
Topic: Startup quit working with tmpfs /var/log
Replies: 3
Views: 183

Re: Startup quit working with tmpfs /var/log

I don't think that will help. Other than utilizing a RAM disk rather than tmpfs, it isn't much different than what I did. It's true it does keep the contents of /var/log between boots, but I don't see how that will make a difference. I will give it a try, though. I suppose it can't hurt.
by lrhorer
Sat Apr 27, 2019 5:19 am
Forum: Advanced users
Topic: Startup quit working with tmpfs /var/log
Replies: 3
Views: 183

Startup quit working with tmpfs /var/log

Prior to making this change, I had this working: I placed the line @/usr/bin/chromium-browser --kiosk http://localhost/cgi-bin/index.cgi in both /etc/xdg/lxsession/LXDE/autostart and /etc/xdg/lxsession/LXDE-pi/autostart (I am not certain which one is not required). As expected, the index.cgi script ...
by lrhorer
Fri Apr 26, 2019 11:56 pm
Forum: Advanced users
Topic: connecting two pi's without internet
Replies: 8
Views: 393

Re: connecting two pi's without internet

Why the router? I see no point whatsoever in putting a router between the two.

BTW, there are a number of ways to accomplish this, and it does not necessarily require static IP addresses. One fairly simple way is to create a SAMBA share on one host and then mount the share on the other.
by lrhorer
Mon Apr 08, 2019 10:19 am
Forum: Advanced users
Topic: vim is weird on RPi
Replies: 2
Views: 308

vim is weird on RPi

This is driving me crazy. OK, I use vim - a lot. I like its features, and it is available on all my Linux systems -also a lot. The version of vim on the RPi systems (or maybe it is a Jessie thing: at this point only my Raspberry Pi hosts are running Jessie) is aggravating , though. Among my top comp...
by lrhorer
Mon Apr 08, 2019 9:20 am
Forum: Advanced users
Topic: Apache cannot open i2c bus
Replies: 1
Views: 200

Apache cannot open i2c bus

I have a web page (CGI script) that needs to issue commands to the i2c bus, but the stock Raspberry Pi won't allow it. I have tried both a Python script and a compiled c program, and neither will open the i2c bus when run from Apache2 on an unmodified system. Both work fine from the command line. Lo...
by lrhorer
Wed Nov 21, 2018 1:45 pm
Forum: Other programming languages
Topic: javascript not working on RPi 3
Replies: 32
Views: 7948

Re: javascript not working on RPi 3

Carl Sagan wrote: Carl Sagan would have been among the first to agree with me completely, right along side Albert Einstein, Paul Dirac, Richard Feynman, Richard Dawkins and a host of other top scientists. For that matter, I am not certain that Carl Sagan did not say the very same thing I did at som...
by lrhorer
Tue Nov 20, 2018 11:35 pm
Forum: Other programming languages
Topic: javascript not working on RPi 3
Replies: 32
Views: 7948

Re: javascript not working on RPi 3

We said we didn't want a protracted discussion of science, math, and philosophy, but I don't quite feel I can let this go. You got it the other way around. Actually, I don't. Some mathematical disciplines are developed specifically in order to help model the real world. This is generally called "App...
by lrhorer
Sun Nov 18, 2018 8:59 pm
Forum: Other programming languages
Topic: javascript not working on RPi 3
Replies: 32
Views: 7948

Re: javascript not working on RPi 3

If the page is never going to be served across any network I would be inclined to not use a webserver. Or at least not the likes of Apache etc. Rather, use that web page with Electron and have the "backend" done in node.js within the same Electron application. That sounds like an excellent idea! I ...
by lrhorer
Sun Nov 18, 2018 8:23 pm
Forum: Other programming languages
Topic: javascript not working on RPi 3
Replies: 32
Views: 7948

Re: javascript not working on RPi 3

Looks good! Despite you're not a webdeveloper, you did a great job! Well, thank you very much. You are quite kind. It's not fancy, and I have had a lot of help. As a matter of fact, we were told at high school that scientific method will work even if we're happen to live in a hologram, an existing ...
by lrhorer
Sun Nov 18, 2018 7:44 pm
Forum: Other programming languages
Topic: javascript not working on RPi 3
Replies: 32
Views: 7948

Re: javascript not working on RPi 3

Uh, oh, it seems I've sidetracked the topic How dare you !! ;) I don't want start a deep theoretical discusson about our universe if you don't mind. I concur. Two, small nits, however. You included math in the list of disciplines that require external validation, but it isn't. No mathematical form ...
by lrhorer
Sun Nov 18, 2018 7:24 pm
Forum: Other programming languages
Topic: javascript not working on RPi 3
Replies: 32
Views: 7948

Re: javascript not working on RPi 3

That's no excuse for sloppy security. It may not be connected today, it may be in the future. No, this is an embedded application. If the end user hacks the platform and opens up the network, that's his problem. Otherwise it sits on the wall and responds to button presses on the front panel and bro...
by lrhorer
Sun Nov 18, 2018 1:45 am
Forum: Other programming languages
Topic: javascript not working on RPi 3
Replies: 32
Views: 7948

Re: javascript not working on RPi 3

I'd like to add one thing on security side: you should use a POST method (add "method='POST'" to the form tag). I am aware of the implications for security, but since this page will never be available to the internet, or indeed across any network, the point is moot. Once the software development is...
by lrhorer
Sun Nov 18, 2018 12:23 am
Forum: Other programming languages
Topic: javascript not working on RPi 3
Replies: 32
Views: 7948

Re: javascript not working on RPi 3

Anyway, the postulates of science are spelled out here Correct, sort of, but if you will look closely, you will see every one of his categories have points that are derivative of the First Postulate. The 1st, 2md, 5th, and 10th postulates are actually derived from the First Postulate of Science. In...
by lrhorer
Sun Nov 18, 2018 12:04 am
Forum: Other programming languages
Topic: javascript not working on RPi 3
Replies: 32
Views: 7948

Re: javascript not working on RPi 3

Um, no. Of course, some of this boils down to semantics, but some is fundamental. First of all, I believe it was Kurt Gödel who showed that every formal system of dedction (mathematical, scientific, logical, whatever) must contain at least one assumption, also known as an axiom, a principle, or a po...
by lrhorer
Sat Nov 17, 2018 2:59 am
Forum: Other programming languages
Topic: javascript not working on RPi 3
Replies: 32
Views: 7948

Re: javascript not working on RPi 3

Yep. It's performing a GET to a CGI script which writes to wpa_supplicant.conf and completes by killing itself and its ancestors. Of course, on your machine, this does nothing, On the Raspberry Pi, it shuts down Chrome, because it is no longer useful, and brings the desktop back up.
by lrhorer
Fri Nov 16, 2018 6:38 pm
Forum: Other programming languages
Topic: javascript not working on RPi 3
Replies: 32
Views: 7948

Re: javascript not working on RPi 3

Nope, that wasn't an assumption, that's a fact. I made a well-educated guess based on many years of experience. A guess, stated as if it were fact, is the same thing as an assumption, with the same potential results. It is an implication, and any inference drawn upon it and acted upon as if it were...

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