LEAP#371 common emitter amplifier biasing

I am inspired once again by one of w2aew’s excellent vidoes to revisit the basics of biasing and operating classes of the common-emitter amplifier.

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub hero_image

LEAP#370 TS3A5018 Digital Switch

Just a quick test of the TS3A5018 digital switch which I am looking at for an application in switching amplifier gain stages.

The TS3A5018 is a 1.8 to 3.6V device with four SPDT switches controlled from a single input, and a master active-low enable pin. It is guaranteed break-before-make (max 58ns).

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub

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LEAP#369 my beeping Boldport ananas

Boldport Club Project #20 is the first designed by Ben, the new Boldporter. And it’s a beauty!

As is often the case, a small but interesting circuit is at the core of a beautiful design. The circuit is essentially four repetitions of an RC phase-shift oscillator. Like other projects such as the famous Cordwood series, the design employs multi-board symmetry and 3D construction.

As always, all notes, schematics and code are in the Little Electronics (more...)

LEAP#368 Granular Synth

The “Granular Synth” idea harks back to an old Auduino project. I stumbled upon it again recently and decided it deserved a quick build in an Altoids tin. As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub

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If you can put up with 5 minutes of me fiddling around, here’s a taste of how it performs..

LEAP#367 nRF24 Scanner

While trying to improve the range of nRF24L01+ some modules, and got distracted into building a channel scanner. The basic code is from the RF24 library examples, but this gets pimped up with a Nokia 5110 LCD display, multiple modes and a handy enclosure.

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub

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LEAP#365 Driving a Nokia 5110 LCD with the Adafruit library

I’ve been having SPI conflicts with other libraries I’ve used for controlling the Nokia 5110 LCD, so time to pull out the big guns - the wonderful Adafruit library set which includes a PCD8544 module.

I started with a few tests of the hardware and software SPI modes.

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub hero_image

LEAP#364 Classic Nokia Ringtone

For obscure reasons, I wanted a version of the classic Nokia ringtone on an Arduino. So… I transcribed the score in Guitar Pro and tested it in a little sketch.

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub hero_image

Here’s a quick demo:

LEAP#363 BINCO fidget counter

The BINCO a binary counter that can be configured to count up or down. It uses Snaptron domes as buttons (on, slow/fast a,d rest). The heart of the counter is a 555 timer driving a 74HC4020D 14-bit Binary Counter from which 11 taps drive some nice reverse-mount LEDs.

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub hero_image

LEAP#362 H-83A 12 song music chip

The H-83A is yet another music chip, this time programmed with 12 tunes. I haven’t figured out all the songs, but they sound like classic Chinese folk tunes.

This chip requires very minimal external components (resistor, switch and power), but volume is decent in all it’s 8-bit wonder!

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub hero_image

LEAP#361 128×128 TFT LCDs

I dug out a 1.44 inch 128*128 SPI Color TFT LCD Module from my parts drawer as a possible display for a project I’m working on. First .. put it to the test and try a couple of Arduino libraries. As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub hero_image

Move Proxmox Container to Different Storage (Updated for LXC)

The Proxmox Web GUI does not give us the ability to migrate a container from one storage device to another directly. To move a container onto different storage we have to take a backup of the container and restore it to the same ID with a different storage device specified. This can be time laborious when working

Reduce Proxmox LXC Backup Size and Time

Proxmox backs up guests byte-for-byte in a compressed archive. Looking at LXC backups specifically, the file system is compressed into the target backup file with just a few exceptions – temp files aren’t included. You can also add your own exceptions by editing the vzdump.conf to exclude specific file patterns. All that said, one of

Gitlab Runner Error: sudo: no tty present and no askpass program specified

After issuing the first build on a dynamically created Container I came across the following build error when running a command with sudo. [crayon-59847f31522f3681093998/] The error is caused by trying to run a command with sudo, however the calling user has not been authorised to use sudo. The error isn’t helpful, and doesn’t really spell out where to

Scripted Install of Oracle Java 8 on Ubuntu 16.04

Please see Install Oracle Java In Debian/ Ubuntu using apt-get for more information. [crayon-59844b9392d4e955734194/]  

Rename a Proxmox Host

Renaming a Linux server’s hostname is usually a trivial task, and that’s no Different to a Proxmox server providing it’s not part of a cluster. If your machine is in a cluster then things get a bit more complicated and that’s a blog subject for another day. For a single node machine it’s simple –

Proxmox 5.0 is now available

Today, the Proxmox VE team have released a new version of Proxmox, incrementing the major version to 5.0! The new version packs in a raft of new features, the headline being the new Replicated Storage feature which enables batch style synchronisation of local storage volumes across servers. You can download the ISO from https://www.proxmox.com/en/downloads/item/proxmox-ve-5-0-iso-installer Highlights

OBI formatting grand totals – without XML!

Recently I needed to have some conditionally formated grand total rows in OBI. I remember years ago hacking around with the XML which is far from ideal. I then realised it could be done another way, here is the example:   Create an analysis with a measure column: Apply the conditional format on the Actual

Generating Diceware Passwords in Python

Today I’m going back to a theme from a post last year and looking at generating passwords with my favourite programming language. A tweet from Simon Brunning pointed me to Micah Lee’s article at The Intercept and my first thought was to write a function to do this in Python. So here it is;

def generate_diceware_password(word_count=6):
    import random
    word_dict = {}
    passphrase = []
    with open('diceware.wordlist.andy.txt') as f:
        for line in f. (more...)

Teaching an old dog to Fish

Inspired by the recent furore around Shellshock I decided that it was time to try an alternative to bash. By the very grown up process of shutting my eyes and poking my finger at the results of a search for “shell” I ended up at fish shell, described by the project as “a command line shell for the 90s”. I’m presuming that this means the 1990s and is not a minimum age requirement.

I’m (more...)

Generating Reasonable Passwords with Python

Thanks to a certain recent Open SSL bug there’s been a lot of attention paid to passwords in the media. I’ve been using KeePassX to manage my passwords for the last few years so it’s easy for me to find accounts that I should update. It’s also a good opportunity to use stronger passwords than ‘banana’.

My problem is that I have always resisted the generation function in KeePassX because the resulting strings are very (more...)