• Alternatives to ordering from Amazon

    Amazon has it’s place as a supplier, but for many things I’d like to avoid their marketplace and buy directly. So, I’m making a public list for myself so I know where else I can look for suitable alternatives.

    Please comment if you know good sources for other products, it will help me and maybe help others. Thanks

    NameURLProducts
    Kenablehttps://www.kenable.co.uk/en/Cables and IT related (computer, audio, network) and accessories. Example, HDMI 2.0 cable, £3 each inc VAT & post £1.07

    Reasons I am trying to avoid Amazon:

    Their product listing and search is awful.

    My experience is the product search results are often for different items than the search term implies. Sponsored listings appear to be prioritised over more correct results.

    I don’t believe they pay their morally fair share of tax

    Tax is complicated. I have no idea how to solve that. Multi nationals will always move money to the lowest possible tax environment before paying dividends to shareholders. That is the nature of our imperfect global tax system and not an Amazon issue alone. Therefore I feel using smaller UK based businesses or wholesalers for a similar spend is likely better in relation to funds reaching our government that can then be spent within our society. Example: https://www.taxwatchuk.org/amazon_tax_cut/ “Amazon UK Services Ltd 2019” Profit: £101m, Tax: £6.3m. 6% doesn’t feel like a fair tax rate to me.

    They have issues with counterfeit products

    They have a system of collocating stock from different sellers in their warehouse if the item is the same. If a seller sends in 100 fake memory cards their fake stock may be sold in place of a seller that sent in 100 genuine memory cards. Even without the colocation, Amazon has a poor reputation for ensuring the products they offer via their market place from third party sellers are safe or legal to sell.


  • Building a low power server

    Note to future me: The reason the new server HDD would not sleep is because ext4lazyinit writes inodes slowly on new disks in the background, so the disks were immediately woken even if forced to sleep.

    Build a low power server…

    It will be easy, says me…

    Replace our 10 year old Atom C2750 running FreeNAS/TrueNAS with a 6 disk raid, that uses 65W of power, with an N100 and 2 disks (+nvme boot disk) on plain ubuntu server. I plan to get it to less than 20W when idle, sure seems I can when checking various blog posts. Processing power isn’t a big deal for this server as it only received backups from the other servers and computers we use.

    So I bought the hardware, setup the server and noticed the disks were always running when I had it next to me.

    I spent days searching the web, trying various sleep commands. Eventually I found the sudo hdparm -Y /dev/sda which forced the disk to sleep… for 1 second before it came back to life.

    Eventually I found a command sudo btrace /dev/sda that told me a ‘ext4lazyinit’ was writing to the disk frequently, led me to https://www.linuxquestions.org/questions/linux-general-1/someone-please-explain-ext4lazyinit-to-me-4175658874/ and https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=bfff68738f1cb5c93dab1114634cea02aae9e7ba and it all makes sense.

    A new file system needs initialising, and that takes time. So now, I’ve reinstalled ubuntu 22.04 for the nth time and this time I’m going to leave it running a week and see if the drives sleep.

    Current power usage is between 30W and 35W.

    … it will be easy, once it’s working.

    Update April 2024: It is now using 18W when idle. It has been difficult working out if a disk is sleeping or idle, complicated by the 2 disks being from different manufacturers and not responding to hdparm (I forget the how and why, will update the commands I need to check status when I next get to look at this). I think I might be able to get to 12W or less…


  • Santa-pi, a music player for a charity fundraising float

    This is a Raspberry Pi. A small, powerful, low cost computer.

    Raspberry Pi Model 3B+

    I’m writing this blog post from the pi you see in the photo. It is very slow compared to my laptop but it works and is in front of me now, whereas my laptop is a whole 2 meters away on another desk.

    This is the Raspberry Pi Model 3 B+ that used to run the background music for my small business, a shop that sells furniture and appliances for kitchens, bedrooms and bathrooms. I retired this pi from service a few years ago when we moved to a different background music service. Before the new company I used Jamendo which allowed me to licence and download a few hundred tracks every few months. I would copy them to the pi over the wifi network and the pi would play the music. I wrote a small script that meant as the pi powered on it would start playing music tracks randomly from the selection I had uploaded to it. No human interaction, once setup it ran and ran and ran. Perfect.

    This year, as many years before, I have volunteered to help Santa travel around Canterbury with the Rotary Club I’m a member of. We had problems this year with the float background music in that the old donated Ipod ran out of power. When connected to a battery the plug frequently dislodged the audio connection and affected the sound quality. I realised I could repurpose my old Pi to make a better sound source for the float.

    Steps

    1. A fresh installation of Raspbian
    2. Find some example code on the internet for auto-starting applications when the pi is powered.
    3. Find some suitable music tracks (search, find, repeat)
    4. Put them in a directory on the desktop called ‘music’
    5. Write a script to autostart the playing of music.
    6. Remember to select the correct audio output (3.5mm AV Jack, not the HDMIdisplay)
    7. Buy a suitable enclosure to secure the pi against weather. The only connections it needs when setup to run is power (through micro-usb) and the 3.5mm aduio jack out to the float speakers. I found a nice circular panel mount connector for those, easy to drill and fit.
    Set the audio output by right clicking the speaker icon in the top right.

    The Script

    Modifying a code idea from StackOverflow;

    create a file: nano ~/.config/autostart/mygui.desktop

    Add the following and save.

    [Desktop Entry]
    Name=AutoPlayMusic
    Exec=/usr/bin/vlc -LZ "/home/pi/Desktop/music"
    Type=Application
    Hidden=False

    Exec starts VLC, the music player application.
    -LZ flags set “Loop” and “Random”, it plays forever in random order.
    “/home/pi/Desktop/music” is where I put the Directory full of music files.

    Restart the pi to check it works.

    In the future anyone can connect a keyboard, mouse end monitor and change the music, although they will have to remove it from the case to access the USB ports.

    The finished raspberry pi auto playing juke box in it’s weatherproof case.


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