This is an attempt to clean up these notes: </2016/03/20/notes-mail-server-madness/> References go there. This post is a summary. ...

Hey! It’s more notes! Orange Pi Lite is, IMO, the only difficult Orange Pi to get working. Primarily, because it has WiFi, and no Network socket. For an OS, use Armbian. http://armbian.com WARNING: the device will be unlit, no LEDs, until the OS image begins to boot. It could be half a minute before you see anything. It can sometimes take a few tries to program the SD card correctly (either that or I’m using bad SD cards)....

Just some notes. To reinstall (upgrade) the OS, go here: flash.getchip.com You’re going to need a USB cable, and a jumper wire/paperclip. Ground the FEL line before plugging it in to your PC. If you’re on Linux, you’ll also have to follow some funny instructions to give your account permission to access the USB port via the Chrome web browser. For me the variable that’s supposed to be your login name wasn’t working, so I just used my login name directly....

Just a bunch of scattered Arduino notes. Leonardo All data pins can be Digital Inputs or Outputs (i.e. D0-D13, A0-A5). Thus, 20 digital I/O pins Caveat: D0 and D1 are shared by the UART bus used to communicate over USB. So if you want to avoid reading/writing weird values while connected to the PC, you may want to avoid these pins. Pins D3, D5, D6, D9-D11, D13 have PWM’s attached to one of 3 (4) timers....

Just a quick set of benchmarks, seeing how fast my servers are at downloading and uploading. These aren’t the be-all/end-all of benchmarks. They’re just a rough look at what the performance of a machine is. The following test is used. Linode, New Jersey: $10 VPS server, 1 core, 2 GB RAM I’m pretty happy with these results. This machine has the fastest SSD I’ve tested, and provide a good benchmark for expected performance....

MySQL/MariaDB has several log files. https://dev.mysql.com/doc/refman/5.7/en/server-logs.html Since moving Ludum Dare to a new server, I ran in to an issue where I was running out of hard drive space. Some details: Ubuntu 14.04 MariaDB 10.1 WordPress, plus some custom stuff 50 GB of SSD space (main partition) 250 GB of additional SSD space (alt partition) The database itself is on the alt partition, but I kept running out of main partition space....

To avoid being flagged a spammer, your DNS server (and SMTP server) needs to be configured for: PTR Records (Host) SPF Records (DNS) DKIM Records (DNS + SMTP) DMARC Records (DNS + an email address) TLS Certificate (an SSL Certifiate for your mail domain) The last one is required to send encrypted mail. ...

These notes are based on this. Install GIT and BC. Get the latest version of LetsEncrypt using GIT, placing it in /opt/. For the next step, we’re going to need access to Port 80, so temporarily shut down your webserver. Run LetsEncrypt. The first time this runs, it’s going to ask for an e-mail address. If everything worked correctly, you’ll find your certificate files here: Where example.com is your domain name....

So this will be an ongoing project. I used to have some old PCs sitting in my closet. They take up a lot of space, and they’re heavy. So on a whim (as it always is), I decided to gut the PCs. One of them, apparently I had already removed the power supply, so it was gone (if I remember, it was quite noisy, so no loss). The other still had its PSU, so I’ve selected it as the donor to my bench-top power supply project....

So basically, this entire series of tool research posts is the result of me searching for an Oscilloscope, and then discovering my existing workflow was bad. I’ve lost count at how many hours I’ve spent doing homework on low cost high value scopes. I’ve explored a variety of offerings from Siglent, Rigol, Owon, Uni-T, Hantek, and others, trying to find the best value. I don’t have the desk space for an old analog scope (which is a way to get a good scope for under $100)....