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Dealing with NIL in JSON::Any in Crystal Lang

One of the challenges when developing with Crystal is that it is not as forgiving about data types as, say, Python or Ruby.nil will keep you occupied.The following error message:cast from Nil to String failed, at /usr/share/crystal/src/json/any.cr:220:5:220can be solved by:# cast to string, THEN check if it is nil if !(shopify_data[spid]["billing_address"]["address2"].as_s? == nil)     name = [...]

By | Mai 30th, 2020|Crystal Language|Kommentare deaktiviert für Dealing with NIL in JSON::Any in Crystal Lang

Chromium exit code -5

While running Chromium with chromium-browser --display=:0 https://www.picockpit.comwill allow you to start Chromium from an SSH connection (and it will output to the main display in the X Server), this will fail when you try to run it with subprocess.Popen in Python:"command": ["chromium-browser", "--display=:0", “https://picockpit.com”](this is part of the JSON format I have specified for PiControl [...]

By | Mai 19th, 2020|Development|Kommentare deaktiviert für Chromium exit code -5

secure command execution with Python: subprocess.Popen

Security is important for me while developing the picockpit-client. The following applies to Linux systems (but probably is applicable to all Unix like systems, including macOS)Python allows to run external commands using the subprocess module.import subprocessIn the upcoming version of PiCockpit, users will be able to create their own buttons (simply editing a JSON file [...]

By | Mai 15th, 2020|Development, Python|Kommentare deaktiviert für secure command execution with Python: subprocess.Popen

Stupid business mistakes #2: trying to cheat people (a new kind of spammer)

A bait and switch site, which was supposed to show me some information about Python code.“Click allow if you are not a bot”. Abusing the Captcha to display notifications (probably spam advertising?) is definitely a clever idea. (From the technical and machination point of view)Why does the person who is behind this not direct their [...]

By | Mai 15th, 2020|Stupid business mistakes|Kommentare deaktiviert für Stupid business mistakes #2: trying to cheat people (a new kind of spammer)

TermiShell: a web-based shell for the Raspberry Pi (development notes)

IntroductionIn the course of development of PiCockpit, I am going to add a web-based Terminal called TermiShell.TermiShell icon, by: Stephanie Harvey via unsplash.com TermiShell is going to allow you to log into your Raspberry Pi using PiCockpit.com (and the picockpit-client) – no additional application required on either side. This should be very comfortable, especially when [...]

By | Mai 5th, 2020|Development, Python, Raspberry Pi Blog, Raspberry Pi Embedded Development|Kommentare deaktiviert für TermiShell: a web-based shell for the Raspberry Pi (development notes)

Use PiCan GPS with an external antenna

the PiCan GPS uses this chip:https://cdn-shop.adafruit.com/datasheets/GlobalTop-FGPMMOPA6H-Datasheet-V0A.pdfit has a Built-in 15X15X2.5mm ceramic patch antenna on the top of moduleandAutomatic antenna switching functionAn external antenna can be attached to the PiCan 2 GPS. Page 17 of the Datasheet has recommended specs for this external antenna. The antenna should be switched to automatically, if I understand it correctly [...]

By | April 9th, 2020|Raspberry Pi Blog|Kommentare deaktiviert für Use PiCan GPS with an external antenna

Creating configuration files in /etc in Debian packages

I am currently working on an updated picockpit-client version, which should add additional configuration files in /etc/picockpit-client for the individual modules (PiDoctor & PiControl).picockpit-client is a Raspbian package for picockpit.com, linking the Web platform with your individual Raspberry Pi.As Raspbian is based on Debian, the following information holds true for general packaging for Debian and [...]

By | April 5th, 2020|Development|Kommentare deaktiviert für Creating configuration files in /etc in Debian packages

Impact of Coronavirus (Covid-19). Update for pi3g Raspberry Pi Customers

Due to the increased impact of the Coronavirus, we would like to give a statement as to the impact on our business, and the supply to our customers with Raspberry Pi products and other products we distribute.Situation with Raspberry Pi Trading & FarnellOur main suppliers are Farnell and Raspberry Pi Trading for Raspberry Pi accessories. [...]

By | März 17th, 2020|Raspberry Pi News|Kommentare deaktiviert für Impact of Coronavirus (Covid-19). Update for pi3g Raspberry Pi Customers

Our own product PCCB: Pi Control Carrier Board

This is a quick overview of our product, PCCB (Pi Control Carrier Board). PCCB is already in a second revision with significantly expanded features.How does it look?What does it do?The PCCB (Pi Control Carrier Board) is an industrial carrier board for the Raspberry Pi Compute Module. It offers several industrial interfaces, and power options.Which compute [...]

By | März 11th, 2020|pi3g Hardware Designs|Kommentare deaktiviert für Our own product PCCB: Pi Control Carrier Board