A logical blog in an illogical world

HD44780 LCD screen on Raspberry Pi 2 and 3 with LibreElec

Posted by Bill Seremetis on 2017, June 17 - 08:38
HD44780 Raspberry Pi3 Wiring

While HD44780 were quite well documented for RPi1, there is some confussion with RPi2/3 with LibreElec. In case you don't know them, HD44780 screens are affordable and easy to use displays that communicate over a parallel connection. They can be attached to an RPi on the GPIO directly, and they are excellent for displaying data without opening your monitor or TV.

Scanning over network on Linux with xsane and a WiFi or Ethernet scanner. (EPSON L386)

Posted by Bill Seremetis on 2017, April 19 - 19:08

While it is very easy to add a network printer on Linux (and any other OS for that matter), a network scanner isn't that easy. For one, searching on the internet for "network scanner linux" or anything like will yield results for programs that scan the network, not for scanning documents over the network. So, the easy way of finding somebody that has done this before you is not that easy.

Is Drupal changing? Dropping support to the corporate part of it.

Posted by Bill Seremetis on 2017, March 26 - 15:51

I haven't blogged for a long time, mainly due to workload. The past 2 years found me joining another team, changing a couple of appartments and working more on the backend than ever before.

I also took part in organizing three (3) big Drupal events in Greece: DrupaDay Athens 2016, DrupalCamp Athens 2016 and DrupalDay Patras 2017! DrupalDays are the new trend as it seems, where the local communities try to meet all together and discuss, present, have fun, but they are not Camps. They are being organised with the bare-minimum costs and held in the local language.

Postfix: Reroute an email, by filtering the sender address, to a mailtrap

Posted by Bill Seremetis on 2015, September 14 - 09:53

When working on sites with thousands or millions of users you have to face a very important problem: your test/dev sites are not allowed to send emails, at all! Develmail and other solutions exist but most of them are very limiting because you end up with text emails and not your nicely styled HTML mail. A way to overcome this problem is by using an external SMTP server that you manage. I'm using iRedmail which works with Postfix. If your server uses postfix then you should be ok in following this guide.

Choosing a proper host: it is not just speed and numbers

Posted by Bill Seremetis on 2015, July 22 - 14:27

In case you missed it, Greece is under capital controls at the time of this writting. Long story sort: we can do whatever we like with any amount of money we might have, as long as we move them through banks (credit cards, bank transfers) inside Greece. Cash is limited to 60euros per day (which is ok for most daily needs).

Transactions with other countrier are not allowed. That includes payments to well known services like Amazon, Paypal, Google and of course to datacenters (Linode, DigitalOcean, Hetzner, you name it).

Creating a list of total flags per user

Posted by Bill Seremetis on 2014, November 25 - 14:52
Drupal: Total flags of type per user

I needed to create a list with the total count of flags, for a specific flag type, made by users. The query to do this for one user is this:
SELECT COUNT(*) FROM flagging WHERE uid=[user_id] AND fid=[flag_id];

Doing this with views, while not very difficult is a bit trivial. You need to start with a node view and not with a user view. From here on things go as follows: