blockdev.io

Home Assistant: No Pi - No Problem!

A brief look into the universe of Single Board Computers (SBCs) and a perspective on why you don't always need or benefit from a Raspberry Pi, and running Home Assistant on other devices.

Business Automation

Automating Payroll payments with Wise and Starling

Automating salary payments using Wise to save time and reduce risk.

mikrotik Featured

Creating Virtual Static IP with Mikrotik, CHR and AWS

My ISP does not provide me a dedicated public IP address either dynamic or static by default*. Instead I have a private address behind a shared public IP. While Internet access works fine, I cannot set up custom port forwarding and as a result cannot access devices on my network

Mini Guides

Mini Guide: Rich MOTD messages with Markdown and glow

A Message of The Day (MOTD) banner is probably fairly familiar to those of us who SSH around, but how about a richly formatted message with colour and style? This mini-guide explains how to add a richly formatted MOTD banner that is displayed to any user starting a new terminal

Dell

Mini Guide: Easy Dell iDRAC access (on Linux)

Dell's IDRAC IPMI/Lights-out/Remote KVM feature is great except for one thing. It's uses Java Web Start to deliver the remote control interface - at least on some versions. The mini-guide explains how to access it from a computer that struggles, or even refuses to run Java Web Start

Mini Guides

Quick AT Commands from the Linux Shell

There are numerous tools available for Linux that allow the user to interact with Serial devices (usually known as Terminals or Serial Terminals), such as mincom or screen to name two, which are generally great at what they do, but experience shows they are not so good for scripting -

Mini Guide: Quick and easy Client SSL Validation (with OpenSSL and Nginx)

I run a number of services from home, for my own convenience, that I want to be able to access remotely, securely, on the go, without the cumbersome need for usernames and passwords all the time. This mini-guide looks at securely identifying the end user with client SSL certificates instead

mikrotik

Monitoring DHCP Leases with MikroTik and Slack

At home I have a fairly extensive network setup that includes numerous switches, wired connections in most rooms, Wi-Fi and over 100 connected devices. Amongst those 100+ devices are numerous Alexas, Raspberry Pis and smart devices in addition to the computers, laptops, tablets, phones, watches and all the usual things.

ngrok

An ngrok custom domain, for free (powered by AWS)

Introduction ngrok and similar tools are great for providing public access to local services, often for development purposes. I primarily use it for exposing an API being developed locally so that a webhook callback can interact with it, for example an inbound email callback from mailgun - it's very useful

mikrotik

Creating a completely isolated guest network using Mikrotik hardware

Creating a physically isolated guest network using iptables and 802.11q VLANs.

git

Hub Clone Tool - Clone all your GitHub Repositories with one command

Introduction I work with a large number of repositories, mostly on GitHub, some are my own but most are for work, and the volume only grows since we complete a lot of projects each year. I find it useful to be able to clone everything I need in a number

Making persistent changes on a read-only Raspberry Pi

Introduction The ability to boot a Raspberry Pi from a read-only file system can be advantageous for a variety of reasons and I've previously written a number of posts that look at use cases and implementation approaches. A key challenge is then making changes, often this requires a reboot to

mysql

MySQL Workbench, Ubuntu 20.04 and App Armor

Recently when installing MySQL workbench on a clean Ubuntu 20.04 install I've run into the following error when connecting locally using a stored password: "An AppArmor policy prevents this sender from sending this message to this recipient.." This post on MySQL forum suggests its a permissions issue between MySQL

arduino

RGB LED Electric Drums - MIDI x Arduino x WS2812

Introduction This is another just-for-fun project which was completed a couple of years ago. I have a number of instruments that I play for the pleasure of it, having had an electronic drum kit for a few years and having had and acquired all sorts of electrical, I was interested

Raspberry Pi

Mini Guide: DHCP Controlled Hostname on Raspbian

DHCP Controlled Hostname on Raspbian Note: This note was originally in the Network Booting a Raspberry Pi 3 from an Ubuntu Server post. In theory the configuration should be as simple as stated below: { ... host pi3-1 { hardware ethernet b8:27:eb:41:8e:fa; fixed-address 192.168.1.59; option

Raspberry Pi

Mini Guide: DHCP Reservations

DHCP Reservations Note: This note was originally in the Network Booting a Raspberry Pi 3 from an Ubuntu Server post. To make life easier DHCP Address reservations can be added in the main body of the DHCP config so that each MAC Address gets assigned the same IP: { ... host pi3-1

Mini Guides

Mini Guide: NFS Debugging

NFS Debugging Note: This note was originally in the Network Booting a Raspberry Pi 3 from an Ubuntu Server post. Initially when trying to understand whether the Pi was booting from the network or not it was useful to enable NFS debugging with rpcdebug -m nfsd -s proc which reports

Mini Guides

Mini Guide: Controlling Screen Blanking

Controlling Screen Blanking Note: This note was originally in the Raspberry Pi 2/3: Chromium in Kiosk mode post. The screen can be turned off using the following command: xset -display :0.0 dpms force off And on: xset -display :0.0 dpms force on These could be used in

Mini Guides

Mini Guide: Pi User and Management User(s)

Pi User and Management User(s) Note: This note was originally in the Raspberry Pi 2/3: Chromium in Kiosk mode post. Auto-login to the GUI works regardless of the pi user's password. It is worth changing this for security, potentially creating a management user which requires a password to

Mini Guides

Mini Guide: Raspberry Pi Memory Split

Memory Split Note: This note was originally in the Raspberry Pi 2/3: Chromium in Kiosk mode post. The memory available to the GPU can be configured by: * sudo raspi-config * Option 7 (Advanced) * Option A3 (Memory Split) This may be useful when rendering more visually-intensive pages.

Mini Guides

Mini Guide: Raspberry Pi Overscan and HDMI Modes

Overscan and HDMI Modes Note: This note was originally in the Raspberry Pi 2/3: Chromium in Kiosk mode post. In some cases the image may not fill the screen. The overscan setting below can help, as well as forcing certain HDMI modes as document [here](From https://www.raspberrypi.

Raspberry Pi

Mini Guide: Raspberry Pi Serial Console

Serial console Note: This note was originally in the Raspberry Pi, overlayfs read-write root, read-only NFS base post. It's quite easy to listen on the serial console as you don't have to worry about the voltage differences. Full documentation here. I have many Prolific Technology, Inc. PL2303 Serial Port devices

Raspberry Pi

Mini Guide: Easier Script Debugging

Debugging Note: This note was originally in the Raspberry Pi, overlayfs read-write root, read-only NFS base post. In trying to get the various options out there working I found a number of debugging strategies helpful, they're mostly simple - First, set -v - put this after the #!/bin/sh (or

Read Only

Mini Guide: Read only Raspberry Pi (without NFS)

Without NFS Note: This note was originally in the Raspberry Pi, overlayfs read-write root, read-only NFS base post. This setup described in the article above also works without the NFS setup. As we plan to have no 'proper' storage and RAM limits the size of writes we can store there's

Raspberry Pi

Mini Guide: Watching the file-system on Linux

Watching the file-system Note: This note was originally in the Raspberry Pi, overlayfs read-write root, read-only NFS base post. NFS logging appeared to be quite opaque to me, so it proved useful to be able to observe the relevant file-system activity. We can watch the file-system activity (when the Pi