Home on Codewrite Dev Blog

Overview

Mon, 01 Jan 0001 00:00:00 +0000

This blog is really for my benefit. In years to come I’ll forget how I did some of this stuff. If I’ve got it written down somewhere I’ll be able to figure it out again. If it helps you too that’s just a bonus!

The topics I am hoping to cover are:

C# and dotnet core
Visual Studio Code
MySQL and SQL server
Amazon Web Services (AWS)
Raspberry Pi
Arduino(s)
Docker
VueJS

I’ve been using Visual Studio Code the last year and a half, so most of my code will be using that.

Check [micro] SD Cards using WSL2

Sun, 08 Mar 2026 00:00:00 +0000

I decided to check all my microSD cards and decided to use f3 - Fight Flash Fraud. I also decided to do this using my Windows PC. So I was going to need to use WSL2 and Ubuntu and set it up using Connecting USB devices. I managed it, but there was enough complexity for me to feel that I needed to write some notes about what I did.

So here it is…

Home Assistant Serial Link to an Arduino

Fri, 27 Feb 2026 00:00:00 +0000

The purpose of this project was to connect an Arduino Nano to the USB port that Home Assistant was running on. For me that is a Raspberry Pi 4 but this solution should work with any Home Assistant hardware. And the reason for using a serial connection over USB (rather than wirelessly with WiFi or similar) could be for many reasons:

Wifi may not be available (e.g. if the network is down)
It is more secure
It is un-jammable

The ultimate plan for me was to create an uninterruptable power supply for Home Assistant from bits that I had:

Updating from Jekyll to Hugo

Fri, 06 Feb 2026 00:00:00 +0000

Today I updated the website to use Hugo instead of Jekyll. This has been on my list of things to do for some time. It should be easier than it is - that was the whole reason I used Jekyll in the first place. Anyway, after several attempts at doing this myself and failing, I decided to let Github Copilot have a go.

I started by renaming the old site to “dev-old.codewrite.co.uk” and then asked Copilot to convert it from Jekyll to a new Hugo site at “dev.codewrite.co.uk”. It took ages (well minutes but I consider that a long time), but it did quite a good job. It summarized what it had done in the readme.md (which I’ve kept in the repo). Rather than editing what it had done I decided to go the full “vibe coding” way, and just asked it to fix things that didn’t look good.

Camera Object Detection in Python, Part 1

Tue, 21 Feb 2023 00:00:00 +0000

I have been looking at TensorFlow and following some of the tutorials. I have a camera that looks out over the front garden using a Raspberry Pi 3. It’s has quite a low resolution and frame rate (deliberately so that it doesn’t use a lot of network bandwidth). The resolution is 640x480 at 3 fps. Usually there is not much going on (which is good) but when something does happen I always thought it would be good to have some automatic processing, and TensorFlow seemed like a great way to do that. I followed one of the [tutorials on a single frame][TensorFlow Object Detection], and it picked out quite a lot of detail, as shown below:

Home Assistant REST Devices and Sensors

Thu, 22 Dec 2022 00:00:00 +0000

A while back (before I was using Home Assistant) I built a COB light controller board. The idea was to have lights under the eaves all round the outside of our house (bungalow). They look like this:

In this picture there are three lights, but around the rest of the house there are about 15 in total on 4 different circuits. I won’t go into the detail here other than to say that there is a controller board up in the loft that uses a Wemos D1 mini which serves up a REST interface to turn the lights on and off. I did a presentation for the London Raspberry Pi group. The link to my GitHub page is here:

Home Assistant on the Raspberry Pi

Mon, 28 Mar 2022 00:00:00 +0000

I use Home Assistant (HASS) around the house to switch some of the lights on and off automatically and to monitor the temperature. I plan to use HASS for other automation tasks, maybe controlling things in the garden (e.g. watering plants in the greenhouse) and inside to turn the heating on and off. In this post will describe what I currently have and some ideas for the future.

The main reason that I like HASS is that it separates functionality, specifically keeping the configuration and control logic away from the sensors and devices. This makes everything much more scalable and maintainable. I could write the software to control everything, but like most software engineers I would rather not reinvent the wheel, especially when you have something like HASS that does such a good job with much less effort.

Arduino Low Power Encryption

Wed, 19 Aug 2020 00:00:00 +0000

This was my experiment in creating a low power Arduino that can communicate wirelessly to a Raspberry Pi using an HC-12. By low power I mean run for a couple of years on a 18650 battery. Encryption should be unhackable by today’s standards.

I did a presentation for the Raspberry Pint group, the video is here.

The code is on my Github repo. I had to do some mods to the Arduino board to make it low power (removing the regulator and power LED resistor):

Arduino Default Libraries

Fri, 14 Aug 2020 00:00:00 +0000

I used to think that the default libraries in the Arduino IDE would be the best available but having come across a couple of cases where this isn’t true I would definitely search for better lib libraries now…

What libraries?

What am I talking about? Well the two that have better alternatives are:

Keyboard

The reason why this didn’t work for me was because the BIOS on my desktop PC didn’t recognize the Arduino Leonardo as a keyboard. So I tried [the HID project][HID-Project] - which works flawlessly.

Generating sounds on the Arduino

Thu, 13 Aug 2020 00:00:00 +0000

This is a small project to read wav files from a micro SD card via an Arduino Nano and then play them directly to a loudspeaker. I’ll state upfront that this isn’t the easiest way to do this (there are MP3 modules and libraries), but I wanted to:

Understand sound generation using a microcontroller from first principles
Have some tools / ideas about how to generate sounds for any future projects

As an idea of the sort of thing I was thinking of - I’ve been thinking of a DIY “ring” doorbell. I already have a camera that can see anyone approaching the front door. A 433.92MHz receiver could detect when the doorbell is pressed (so no new doorbell required). A Raspberry Pi (i.e. the one with the camera) controlling it all and sending and receiving to my mobile phone. A lot more work than just buying a Ring doorbell - but a lot more satisfying!

NRF24L01 on Raspberry Pi

Sun, 07 Jun 2020 00:00:00 +0000

OK, so just for the record, I’ve tried using the NRF24L01 on the Raspberry Pi (via tha GPIO SPI pins) and I don’t recommend it.

So the following is just a record of what I did, in case I ever change my mind :).

NRF24L01 Side Wire Raspberry Pi Side
------------- ---- -----------------
MISO White GPIO 9 (SPI_MISO)
SCK Grey GPIO 11 (SPI_SCLK)
CE Orange GPIO 25
GND Black GND (PIN 20)
IRQ Brown GPIO 22
MOSI Purple GPIO 10 (SPI_MOSI)
CSN Yellow GPIO 8 (SPI_CE0)
VCC Red 3.3V (PIN 1)

The Raspberry Pi code consisted of two python files which had to be in the same folder:

Dotnet Core on Raspberry Pi

Wed, 15 Apr 2020 00:00:00 +0000

Source Code on GitHub

Next: [Creating the solution in Visual Studio Code…][RPI-dotnet-software]

This week’s project has been writing the software for my GPIO board on my Raspberry Pi. I added this board to a case I bought for my Raspberry Pi 3+. I designed the GPIO board with a few things in mind:

I wanted a couple of buttons so I could do things like shutting the Pi down (it’s not a good idea to just unplug the power)
I wanted a couple of LEDs so I could display a simple status
I wanted to control the fan so it wasn’t on all the time, just when it was needed (like a laptop fan)
The piezo sounder was added because there was space - so maybe I’d be able to get the Pi to do audible notifications

[This was mainly for when I was running the Raspberry Pi headless - so there wouldn’t be a screen or keyboard connected.]

Setting Up Jekyll

Thu, 02 Apr 2020 00:00:00 +0000

The first thing I did was installed Ubuntu on windows

Then I installed NodeJS and NPM (which I’m not sure if I needed).

And then installed Jekyll

To run it: jekyll serve --host=0.0.0.0

I edited .bashrc to add the GEM exports

1# Ruby exports
2export GEM_HOME=$HOME/gems
3export PATH=$HOME/gems/bin:$PATH

I added a couple of files to the _includes folder:

head.html

 1<head>
 2 <meta charset="utf-8">
 3 <meta http-equiv="X-UA-Compatible" content="IE=edge">
 4 <meta name="viewport" content="width=device-width, initial-scale=1">
 5 {%- seo -%}
 6 <link rel="stylesheet" href="{{ "/assets/main.css" | relative_url }}">
 7 <link rel="stylesheet" href="{{ "/assets/css/main.css" | relative_url }}">
 8 {%- feed_meta -%}
 9 {%- if jekyll.environment == 'production' and site.google_analytics -%}
10 {%- include google-analytics.html -%}
11 {%- endif -%}
12</head>

in the file above I added a link to my css file - which is built from main.scss in the assets/css folder.