The Arduino EEPROM library provides the read() and write() functions for accessing the EEPROM memory for storing and recalling values that will persist if the device is restarted or its operation interrupted. Unfortunately, these functions only allow accessing one byte at a time. The float, double (the same as float on most Arduinos), and long data types are all four bytes long, and the int data type is two bytes long, the same length as the word data type. Some trickery is needed to easily store and recall these values.
I ran into an interesting issue when trying to connect to a new printer with my Linux laptop. The printer firmware was set up for 250000 baud and for some reason I couldn’t connect to it. After a little searching, I found that this was a known issue in pyserial with newer kernels and there’s a quick fix.
I’ve had this socked away for a while, but was just reminded of it. This is a method of concatenating PDF files. This takes multiple PDF files as inputs and outputs a single PDF file made up of those. This is particularly useful when a document needs to include sub-documents, such as a report that includes preexisting data sheets, or a proposal needs to include financial statements, resumes, or other supporting documents.
If you manage any websites, you should be aware of the risk of publishing an email address publicly. SPAM bots spider the web looking for these email addresses, adding them to lists that are sold and used to inundate you with glorious offers of organ enlargement and cheap watches. Today I encountered the most robust solution that I’ve yet to see.
I just discovered that magnet links didn’t work out of the box in Chromium on CrunchBang Linux.
I tried a couple of other fixes found in other places and figured I’d repeat the one that worked here in case it can be helpful to someone.
The solution that worked came from here, although it turned out that only this one command was necessary.
xdg-mime default transmission-gtk.desktop x-scheme-handler/magnet
When I first got started with Arduino under Linux, I quickly discovered that I had issues connecting to the Arduino to program it or talk to it via serial. I later found the same issue when I started working with 3D Printers, when trying to connect the host application to the printer to operate it.
This was clearly a permissions problem, as all of these cases (and other USB serial devices) worked just fine when run as root (not a good practice, don’t do this). This is just a quick post showing how to set yourself up with the permissions needed to use these devices as a normal user.
I’ve got an HP LaserJet Professional M1212nf MFP printer at the office, and most of the machines in the office are running CrunchBang Waldorf. The stock version of hplip does not include the drivers for this printer.
This is just a quickie, nothing too in-depth here. I just thought I’d mention that I’ve migrated all of my computers from Ubuntu to CrunchBang. I enjoy the lighter and more responsive interface, as well as the lower system overhead. It fits my workflow and interaction style well.
I don’t need a high degree of customization to be happy, I just want my customizations to conky and the openbox menu to be consistent between my various computers.
As mentioned in one of my prior posts, I had a server that kept remounting the hard drive as read-only because of filesystem problems. The problem it was encountering was an aborted journal, which was identified by fairly unambiguous language in the output from ‘dmesg’. The solution, of course was to rebuild the journal.