Category: Project

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Another USB-C upgrade

USB-C conversions are becoming a bit of a thing around here. We repaired a faulty work light earlier this year, and we took the opportunity to upgrade the charging socket to USB-C. A few other items have had the same treatment over the last few months. This latest one is an old-school light box for viewing film negatives and slides. We’re still keen on our film photography at TOG, and we still have all of our dark room equipment. 

As-built, this particular light box came with with a foot-long fluorescent tube. Inside, there is a driver PCB for the tube, and a 6x D-cell battery compartment. It also has a 3.5mm power input socket if you want to run it from some kind of adapter.  

The small driver PCB inside takes the ~9V battery voltage and bumps it up to the high voltage required to to run the fluorescent tube. The switching transistor on the driver has already failed once in the past, and its heat sink gets very hot during operation. Probably not a very optimal design or power efficient.

A bit of work with a Dremel and we have a nice oval hole for the new USB-C socket. A few touches with a soldering iron to melt the plastic, and the socket is now joined firmly to the case. The intention was to feed in 5v, and then bump it up to something closer to 12v to charge the batteries via a current limiting resistor. A cheap voltage converter sourced from the usual websites would look after that.

That was the intended upgrade, but a bit of feature creep came along last night. We thought that it would be nice to replace the fluorescent lamp with a more power efficient LED one. This would also allow us to eliminate that iffy driver PCB. Rummaging around the space, an old emergency light fitting had a nice LED strip ripe for harvesting. Check back in with us over the next while to see the finished article. If you have anything that you think might benefit from a USB-C upgrade, drop in to our regular Monday and Tuesday open nights.

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Monitor Your Home Energy in Real Time with ESP32 and Home Assistant

Check out this wirte up by our member Christian Kortenhorst.

With energy prices climbing and smart homes becoming the norm, having a clear view of your household power usage has never been more valuable. That’s what motivated me to create a compact, real-time energy display powered by an ESP32 and a 2.8″ TFT touchscreen—fully integrated with Home Assistant for accurate, live data at a glance.

Why I Built This
I already had a power monitoring system installed through my home energy provider. While it gave a general idea of usage, it was far from ideal:

  • It only updated every 30 minutes to an hour, making real-time decision-making impossible.
  • It didn’t show live solar production, even though I had solar panels installed.
  • It lacked any visual clarity—just vague numbers with no context on where power was flowing.
  • Most importantly, there was no breakdown of grid vs solar vs battery usage. – Without opening my phone
  • Also existing power monitor does not do negative number so any feedin from solar does not show.

That’s when I realised I needed something more flexible, accurate, and immediate—custom-built to show the exact figures I cared about.

Old OWl monitor

The Hardware

Here’s what I used for this project:

  • ESP32 Microcontroller – Powerful, Wi-Fi enabled and Arduino-compatible. https://www.amazon.co.uk/dp/B0DXFBKKQB?ref=ppx_yo2ov_dt_b_fed_asin_title
  • 2.8” TFT Touch Display (320×240) – A colourful and responsive screen with touch input, perfect for compact dashboards.
  • Home Assistant – My existing setup, which already tracks energy through integrations like the Energy Dashboard or MQTT sensors. Shelly

What It Shows

The display cycles through or organises a simple dashboard view with key stats:

  • 🌞 Solar Power: Current generation in watts.
  • 🏠 Home Consumption: Real-time power draw.
  • ⚡ Grid Usage: Whether I’m importing or exporting electricity.
  • 🔋 Battery Level: Charge percentage and power flow.
  • Water temperature in boiler

These are live, accurate figures from my energy system—not delayed estimates.

How It Works
The ESP32 fetches data from Home Assistant using either its REST API or MQTT feed. I chose to parse JSON data from Home Assistant’s /api/states endpoint, which allows me to pull specific sensor values and display them on the TFT screen.

To keep it fast and responsive:

  • Sensor values update every few seconds.
  • Touch input can be added for toggling views or brightness.
  • The layout is clean, using large fonts and colour-coded elements for clarity.
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What Was I Thinking? Revisiting an Old Project (and Its Cable Mess)

Check out this reflection from our member Jeffrey Roe on returning to a project he first worked on over a decade ago.

Back in 2009, I moonlighted as an art technician, working with artist Liam O’Callaghan on an ambitious audio-visual installation involving vintage record players, relays, and looping vinyl. At the time, I didn’t give much thought to cable management. I just wanted it to work, and it did.

Over a decade later, that same installation was pulled out of storage for a new showing at the 2025 Drogheda Arts Festival. Rebuilding and repairing something I made in my early days was a humbling and hilarious experience. I was faced with mystery wires, unlabeled plugs, cryptic C++ code, and lots of “why did I do it this way?” moments.

The Technical Overview

The installation is made up of eight vintage record players, each with a unique vinyl record acting as a sound sample. They’re all triggered in a choreographed sequence, starting and stopping in time to form a layered mechanical symphony.

To achieve this, two Devantech USB-RLY16 relay boards (8-channel, 16 Amp) control the power to each turntable. A C++ program communicates with the boards over serial to switch them on and off at precisely timed intervals.

Audio from the turntables is routed through a M-Audio Fast Track Ultra 8R into AudioMulch, which is used to smooth transitions and apply real-time effects like fades and filtering. The whole thing runs on a laptop with Windows XP(yes, really), using the Windows Scheduler to automate playback sequences.

The Refurbishment Timeline

Here’s how it all came back together over five repair sessions:

Night 1: Repaired two record players, replaced worn-out speaker wires, and rewired new plugs.
Night 2: Fixed a turntable spinning in the wrong direction, replaced a few needles, and swapped out a failed unit.
Night 3: Reconfigured the soundcard defaults and added much-needed labels (finally!).
Night 4: Final testing and adjustments to get everything running smoothly.
Night 5: Automated the entire performance loop and added safeguards for show reliability. That meant rechecking the schedule triggers, failover behaviour, and adding some emergency manual controls in case something went wrong mid-show.

Lessons From the Past

Seeing my younger self’s wiring choices was a reminder of how far I’ve come and how much I’ve learned. If I were rebuilding this today, I would:

  • Use modular smart nodes like ESP32S with MQTT or OSC for cleaner communication
  • Create a simple web-based interface for testing and configuration
  • Avoid the cable jungle with proper labelling, documentation, and good cable management

Still, there’s a charm to seeing something so handmade still working after all these years.

The Show and What’s Next

Bit Symphony was exhibited over the May bank holiday weekend at the Former Methodist Church on Laurence’s Street as part of Drogheda Arts Festival 2025. The response was fantastic. Visitors were fascinated by the tactile, analogue-meets-digital nature of the work.

📸 Check out a gallery of photos from the rebuild and exhibition here: [Photo Gallery Link]

Thanks to everyone who stopped by, asked great questions, and appreciated the slightly chaotic beauty of eight record players making music together. Who knows, maybe in another 10 years, I’ll be repairing it again (with better cable ties this time).

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Sending Pictures Over the Airwaves – SSTV with a Raspberry Pi Pico

Here’s a project write-up by our member Jeffrey Roe, who recently built a Slow Scan TV (SSTV) demo using a Raspberry Pi Pico. He showed it off during the IRTS AGM weekend and radio rally—blending hardware, software, and radio in true hacker fashion.

For the IRTS AGM weekend and radio rally, I wanted to put together a fun little demo to show off something radio-related that combines both hardware and software tinkering. The result? A working SSTV (Slow Scan Television) transmission system using a Raspberry Pi Pico. The aim was to send images over audio and decode them via amateur radio equipment—or in this case, a phone and an oscilloscope during testing.

Like all great projects, this one started with the classic struggle: trying to avoid soldering… and thinking it would only take an hour. How wrong I was!

Eventually, I gave in and soldered up a 3.5 mm audio jack breakout to plug into the breadboard cleanly. From there, things started to fall into place. I used a universal PCB with header pins and cut it to a smaller size.

With the jack connected and audio output sorted, it was time for some proper testing. I had an app on my phone I’d always thought might come in handy one day—and it finally did! Phyphox is like a mini lab on your phone. It can generate audio waveforms, which are perfect for our use case here. I used it to generate tones and verified the signal with an oscilloscope.

Once the circuit was wired up on the breadboard, the project used the following parts:

PartQuantity
320×240 ILI9341 display1
Raspberry Pi Pico1
10kΩ resistor2
100nF ceramic capacitor1
3.5mm Stereo Socket1

With everything connected, it was time to dive into the code. I followed the fantastic SSTV code by Jon Dawson, written for the Raspberry Pi Pico. The setup was straightforward, and before long, I had the system sending out a test image—a cat from @choiceIrregular, naturally—via SSTV.

If you’ve never heard SSTV audio before, it’s… unique. I captured a short video of the transmission. (Fair warning: it’s not exactly soothing—so maybe turn the volume down. Bonus: you can decode the audio from the video too!)

The final step was hooking the system up to a radio for real over-the-air transmission. On the transmission side, I used a USB-C to 3.5 mm adapter connected to my phone (using the SSTV Encoder app), paired with a “Kenwood” 2.5 mm TRS to 3.5 mm TRS connector-to-bare-wires cable. Using a connector block, I had a rough-and-ready USB-to-mic cable.

On the receiver side and another radio, I used another “Kenwood” adapter—this time to a 3.5 mm female socket—and then a simple 3.5 mm audio cable into my device.

And it worked! 🎉
Bonus: The photo below is a selfie of the project itself.

This little project was a great way to showcase digital image transmission using amateur radio, with a modern twist via the Raspberry Pi Pico. It sparked some fun conversations at the rally and hopefully inspired a few fellow hams to try it out themselves.

There’s also lots of scope for improvements. Here are a few ideas:

  • Moving it off the breadboard to make it more robust for events
  • Adding shielding—if I transmit too close, the screen goes white (I suspect interference on the SPI bus)
  • Saving received images—the screen has an SD card slot
  • Automating the sending side—currently, I have to hold the PTT button manually

If you’re curious about trying this out, I highly recommend checking out Jon Dawson’s guide, the inventor of the project:
👉 https://101-things.readthedocs.io/en/latest/sstv_decoder.html

73s!

— Jeffrey Roe, EI7IRB

📸 Photos from the IRTS AGM Weekend & Radio Rally

Joe (EI3JVB), before and after his image was sent via SSTV. Check out our gallery for more!

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Stopping Time: A Sensor-Driven Interactive Art Installation

At Tog Hackerspace, we love helping artists bring their visions to life by combining technology with creativity. One recent project, led by me, Jeffrey Roe, involved modernizing an older artwork that originally used a film camera, and upgrading it to use a digital projector and new sensors. The high-level concept was simple but striking: if a person was detected in front of the screen, the video should stop, and the screen should go black.

This collaboration took place over several months, working around the artist’s availability and my own time outside my day job. We began by choosing a Raspberry Pi as the brains of the project. Initially, I used an ultrasonic distance sensor to detect when a person was present. I wrote the control software in Python, using VLC Player to handle video playback. The script managed VLC through subprocess calls, ensuring that the video would start and stop as needed. To make the setup more seamless, the Raspberry Pi was configured as a server to auto-start, log in the user automatically, and hide the mouse cursor from the screen.

Continue reading “Stopping Time: A Sensor-Driven Interactive Art Installation”
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Pizza Oven Overhaul

From almost the very beginnings of TOG, our monthly Saturday evening Open Social has been a constant fixture in our calendar. At our Open Social in January 2015, a quick hack over the previous few weeks at making a brick pizza oven from a stack of red bricks and some bits of angle iron turned out to be an unexpected instant hit. Our Open Social was changed forever, and has become as much of an outdoor event as an indoor one, irrespective of the season.

We were blessed in TOG 2.0 (Chancery Lane) to have our own private yard where we could leave the oven permanently. Fast forward to TOG 3.0 (Blackpitts) where there was a large outdoor car park, but we couldn’t leave stuff out there permanently. The solution was to create a mobile pizza oven that we could wheel in and out as required. Using a gym ball as a mould, we made our current mobile pizza oven.

After 7 years of hard use, it was time for a bit of well deserved maintenance. The top was removed and the base refilled and leveled with fresh perlite. New dedicated fire bricks instead of red bricks were laid out for the base. Unlike the previous red bricks, these fire bricks are all identical in dimensions and have now made a super flat cooking surface. The inside of the dome got some re-pointing with new red pottery clay.

At our combined Open Social and 16th birthday party last week, the newly refurbished oven was put to the test. The pizzas were fabulous. Thanks to Conor for making the dough! Being a maker space, you get to prepare and cook your own pizza. We even have peels that we made ourselves. We are a maker space after all! To see the oven in action and to have a go yourself, drop into any of our Open Socials.