I’m consolidating the code* sites and that means that there will, all going well, be no new posts here. Instead, I’m breaking in a new site at codepope.dev. There’s already a post up (with code) about the PyPortal. So, maybe see you there. It’s going to be a work in progress (no comments yet), but see you there – you can get in touch through Twitter (@codepope) if you want.
Levelling the Word Clock
Cyntech do a word clock – an 8×8 array of neopixels, a set of acrylics to make a box and stencils for the words and space to fit in a pi zero or pi 2/3 inside. It’s been built here for a while and suffering from random light shows on the display and dropping the WiFi.
Well the light shows were down The the fact that the neopixels work at 5v but the Pi data line is a beefy 3.3v. Not enough juice means the display data line is susceptible to noise. The solution is a level shifter which bumps the voltage from 3.3v to 5v. I used a 74ACHT125 to do this. It’s capable of shifting 4 lines but I only needed the one.
I laid out the first pass as per anAdafruit tutorial on the subject, with a breadboard. And it worked. The next challenge was to get that inside the case of the clock.
For that, I put an Adafruit permaproto 1/4 size board to task, and replanned the circuit with a single three female header to clip it onto the 8×8 display, then added 3 fly leads to connect to the Pi. I started wiring it up with hookup wire but for fun switched to some 30awg cable which made the process super quick and rather tidier.
And it worked first time…. then I had to put it all back in the box. I hadn’t allowed for the Pi’s USB leaning on some unused tracks on the permaproto board which makes it tilt slightly but its generally all fine and does work. I wonder if my next stop would be getting a PCB design for a super compact version….
It all does beg the question though of why would someone sell a kit which really needs a level shifter. You can hack it with a diode too apparently….
Fireworks, like a…
So in the background, I’ve been playing around with digital fireworks on various LED displays, mostly on the Raspberry Pi Zero with PS3 controllers and well that was going on with various levels of success and then I took a break from that approach. I noticed that I had an ESP32 Feather and a 3.5″ Featherwing touch screen. What the heck, I said and a few hours later…
So touch and out come the particles…. want to see the code? It’s Arduino code and it’s up on Github at https://github.com/codepope/fireworks-esp32.
All change… to MongoDB
Elsewhere: NewsBits on Java 11
As is my way, I’ve been writing elsewhere for a living among other things and here’s the latest NewsBits I gathered up….
- Java11 arrives with long term support and warnings.
- Refactoring .then() added to Microsoft’s TypeScript.
- Ready for PostgreSQL11, PostGIS 2.5.0 released.
- Your own database Arnie: pg_terminator kills PostgreSQLconnections.
- Make SQLprettier with sqlfmt.
- Read about CrimsonDB‘s adaptive key/values.
- Kubernetesgets a TLS bootstraping update.
- And Finally… How to scan a Rocket.
Interested? Read the bits in full on https://www.compose.com/articles/java-11-arrives-newsbits-at-compose/
Elsewhere: NewsBits – Redis 5 RC 5
I’ve been doing my usual Friday news gathering for the day job and that means here is todays NewsBits…. Here’s what’s in it:
- Redis 5.0 gets a new release candidate and controversy.
- Updates for older MongoDB versions.
- A guide to analyzing slow MongoDB queries.
- Making MySQL‘s shell shine.
- Google open up Dataset Search.
- Firefox 62 lands, as does the new ESR release.
- HTTP2 support no longer experimental in Node 10.10.
- VS Code gets a new Settings UI.
- Checkout pull requests with the latest Atom.
- Where to get Java support in the future?
- And whats it like migrating to Java 11?
- And finally an SQL puzzler…
Click here to read Compose’s NewsBits (be meeeee!) for this week
Elsewhere – NewsBits (end of August Edition)
In the most recent NewsBits (NewsBits at Compose.com’s Articles) there’s some minor DB and driver updating, a DB that branches like git, a fresh Vault, what happens to SSDs when they meet database write loads, the new Go 1.11 (and 2 drafts) and… oh yeah who wants to see round corners?
(Apologies for the lateness… I’ve been playing with MicroPython, CircuitPython, ESP32s, ESP8266s and a selection of tiny light emitting things…. more on that soon… promise)
Elsewhere: NewsBits for August 24th….
As is my Friday wont, I wrote up NewsBits for Compose but then things move fast… since that was published Go 1.11 has landed… Really looking forward to using that in anger (good anger, not “damn computer” anger).
(Today’s a HackWimbledon day and I’ll be there possibly assembling a RasPad and Featherwings….)
Here’s my regular Friday database and developer news from Compose:
• PostgreSQL stable updates all round.
• And there’s a new PostgreSQL 11 beta.
• How well does PostgreSQL work with a GPU?
• Redis 4.0.11 is all about timing.
• While Redis 5.0 RC4 hardens its streams.
• JanusGraph 0.3.0 edges the graph database forward.
• A first update for MongoDB 4.0.
• CouchDB 2.2 makes storage pluggable.
• Google’s Dart 2 is stable and released.
• MkDocs site builder is 1.0.
• After 6 years of development Julia reaches 1.0.
• And finally, some big 6502 news…
Kindle hacking and clocking…
There’s a super little Instructable on how to make a Literary clock using a Kindle. Well, I happened to have an old school original Kindle 3 about and dived it. Some observations….
- The jailbreaking materials for the Kindle are functional but there’s so many images out there its easy to see why people can get confused.
- The USB/Wifi Networking hack is pretty good to work with when you’re doing USB only, but I wasn’t sold on Wifi configuration, so I stuck with USB and the joy of self-assigning IPs.
- The instructable’s own assets are easy enough to install and get running. It basically wakes up every minute and puts up the appropriate image as pre-rendered on the desktop with a Python script.
- The time is wrong, even when set to BST and I can’t seem to correct it. Timezones seem to be odd inside the Kindle, TZ adjustments seem to only work in the negative. Still, proof of concept…
- Swapping the display image sees the screen flash a few times which would be nice to reduce.
- And it has to be a passive USB power supply to stop the USB disk mode kicking in.
But it is rather splendid and has set me on a course of looking at the Kindle and a slab of ePaper with a small Linux to hand and an ability to run Python. Now, thats interesting…
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