December 10 2024 Python GUIs, PPDs, Raspberry Pi Pi500

Bernie demonstrated how he had developed a Python GUI to provide a service needed in an astronomy context to an Instrument Neutral Distributed Interface (INDI). He needed a general purpose client but using ncurses was impractical as it doesn’t work in Windows. He first showed an example using ncurses running locally on a Raspberry Pi which turned an LED on and off by talking to the service.

When you import a GUI framework, you get a lot of widgets; he demonstrated with an example of the code used with Tkinter, the standard Python GUI, turning an LED on and off. The advantage of using the Gtk libraries is that they are on the Raspberry Pi and they are easy to install in Windows.

However he had settled on the Textualize library which draws things to a terminal client, and therefore is OS agnostic, gives you all the widgets and uses CSS. You can link actions and bind keys to functions and achieving everything only took one little file.

Mike asked how one would print using commercial printers and John said that you would need to find out whether the manufacturer supplied a Linux PPD for that particular printer or just supported Windows and Apple. If they supported Linux, you could install the PPD and configure it using CUPS.

Mike also expressed an interest in finding programmers whom he could recruit to develop software and how you could find ratings for programmers. There are programmers advertising the skills they have. But John warned that all the best programmers are employed; those who need to advertise are unlikely to be the best. Bernie mentioned UpWork for freelancers — there are others — but Mike commented that the responses often come from agencies who put it out to their contacts and so you get bombarded by all of them.

Mike clarified that he was really looking for someone who could support a number of people with businesses and John suggested that he needed to look no further than our members.

Bernie mentioned the Raspberry Pi Pi500 and wondered what its market might be with only 32GB storage. John suggested that schools using a server based network would find them cheaper to use as a terminal for the server than a Windows machine. This led into a discussion of SSD hard drives and their advantages. John said that a 1TB revolving hard drive would take 24 hours to back up whereas a 1TB SSD would take only four hours. It is important to make sure that any SSD hard drive you buy matches the firmware of your computer; go to Crucial to check out the correct SSD for your device.

Bernie commented that Cash Converter has lots of cheap devices and John suggested that this might reflect supply and demand; too many are coming onto the second hard market and so the prices are dropping.

Mike is unhappy that the Gnome icons no longer show in X as Gnome has adopted Wayland; various suggestions were made such as Cinnamon on Linux Mint, Xfce or Mate which is available on Arch.

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