December is a time to get cozy, sip a warm drink, and scroll through long lists about the previous year. So make yourself a cup of tea and settle in for a good one.
With so many events on our calendar at Iffy Books, it can be tough to consistently post documents from workshops after they’re done. I’m thus taking a moment to reflect on 2025 and put things in order, alphabetically. I’ve made a list of 25 projects from the past year that have handouts/graphics/code associated with them, including some misfires and not-totally-finished experiments.
Here we go!
5W Breadboard Amplifier
A one-off workshop for the People Power Media Fest in October. We soldered header pins to an amplifier board and a micro USB port, then assembled a circuit with audio input/output hardware on a breadboard. To test it, we connected an MP3 player and a salvaged speaker and played some music.
• Breadboard_5W_Amp_diagram.png
• Breadboard_5W_Amp_Kit_Label.png
Breadboard MP3 Player
This project is built around the DFPlayer, an MP3 player module with a microSD slot and a built-in amplifier. We’re using a Pi Pico (with pre-soldered header pins) to issue serial commands that change the track and adjust the volume. The first workshop is on December 30th.
• https://iffybooks.net/breadboard-mp3-player
• https://github.com/iffybooks/breadboard-mp3-player
Cassette Tape Loop Workshop
We host cassette mixtape workshops periodically, but over the summer we switched to making loops instead. We’d disassemble a cassette, cut a strip of magnetic tape using the template, and attach the ends with Scotch tape. Then we’d listen to the loop and record over it until the ends came apart, which usually didn’t take long. Tedious fun!
Citrus Battery Kit
If you visited the shop this past spring, you may have seen a bowl with three lemons and three oranges connected by wires, powering a little green LED. It stayed lit for seven weeks! If you want to try making your own, we have a few kits left.
• Citrus_Battery_Kit_Instructions_Iffy_Books.png
• Citrus_Battery_Kit_Label_Iffy_Books.png
DIY Guitar Cable
We made a lot of guitar cables at Iffy Books in the first half of 2025, with varying degrees of success. This was intended as a quick beginner soldering project, but ~25% of people who took the class found working with the wires difficult in a not-fun way. So it’s off the calendar for now.
• DIY_Guitar_Cable_Kit_Label_Iffy_Books.png
DIY Macro Keyboard
We start by soldering mechanical keyboard switches to a Pi Pico, then we use CircuitPython to make the device emulate a regular USB keyboard. Pressing a key on the macro keyboard triggers whatever keyboard input you want (e.g., an email signature or shortcut).
• https://iffybooks.net/diy-macro-keyboard
• https://iffybooks.net/diy-macro-keyboard-code.py.txt
Double Dice One-Time Pad Encoder/Decoder
A memorizable scheme for encrypting short messages without a computer, using 6-sided dice to generate random keys. I put this workshop together for the Philly Anarchist Skillshare back in October, a somewhat low-key event that changed location at the last minute because a reporter on Fox News called attention to it.
My previous attempt at teaching one-time pad cryptography was way too complicated, so I’ve been thinking about ways to improve it over the past few years. I’m really proud of this one, especially because the encoder/decoder sheet can be recreated by hand.
• https://github.com/iffybooks/double-dice-one-time-pad
ESP32 Breadboard Display Kit
We’ll introduce this kit in 2026 with a workshop on building a wi-fi weather forecast display. Stay tuned!
• https://iffybooks.net/esp32-breadboard-display
Host a Website at Home
A workshop and zine on how to host a real website at home. I’ve been writing and rewriting the zine for over a year now, adding and rearranging things based on feedback from workshops. The newest version (coming soon!) adds HTTPS support and better instructions on configuring your Verizon router. And we’re now using a Python script to handle IP address changes instead of the glitchy DDNS services we started with.
• https://iffybooks.net/home-server
• https://github.com/iffybooks/host-a-website-at-home
• https://iffybooks.net/ip_address_check.py.txt
• Iffy_Books_unattended-upgrades_bookmark.png
Li’l Info Box
Folks who caught this workshop built a tiny e-reader-type device with a 1-inch OLED screen, a Pi Pico, and a rotary encoder knob to turn pages. We had memory issues with MicroPython when trying to display long text files, and without wi-fi the device has limited usefulness. So the ESP32 Breadboard Display Kit is sliding in to replace it.
• https://iffybooks.net/lil-info-box
• https://iffybooks.net/info-box-code.py.txt
Linux Lab: E-Z Command-Line Encryption
A command-line information security exercise for total beginners. Participants get into pairs, encrypt files using OpenSSL, and exchange them using a temporary file locker site. If you’re a macOS or Linux user, OpenSSL is already installed!
• EZ_Command_Line_Encryption_SCREEN_Iffy_Books.pdf
• EZ_Command_Line_Encryption_IMPOSED_Iffy_Books.pdf
Make a Hand-Coded SVG Holiday E-Card
For this workshop we use a plaintext editor and a web browser to create animated vector graphics from scratch. Participants so far (myself included) have been getting deeply absorbed in this project in a way that makes me think we should keep doing it.
• Make_a_Hand-Coded_SVG_Holiday_E-card.svg
• Happy_Birthday.svg
Meshtastic 101
We ran our Meshtastic 101 workshop 19 times in 2025, and they’ve been getting more crowded as the mesh chat network has taken off across Philly. So we’ll keep doing them! I updated our how-to zine back in March, and I’ll return to it in the next few months. In the meantime, check out PhillyMesh.net to learn more about the local Meshtastic scene.
• https://github.com/iffybooks/meshtastic-zine
Model Internet Club
The Model Internet Club re-formed in 2025 and we finally (sort of) know what we’re doing. We found a wi-fi router that runs OpenWRT beautifully, with custom domain names pointing to the websites we host on our laptops and single-board computers. More importantly, we have a core group of members who are great at helping newcomers feel welcome.
• Iffy_Books_Python_Local_Website_bookmark.png
• Model_Internet_Club_Handout_Nov_2025.pdf
Pico MP3 Sampler
The CircuitPython programming language added MP3 audio support back in 2024, which means a Pi Pico’s 2MB of storage can now hold several minutes of compressed sound. For this workshop we built a digital synth/sampler device with 10 buttons, each triggering a drum sample or sound effect. The quality is pretty good, but there’s a catch: a loud click whenever the device starts playing audio. I tried to mitigate it with some extra circuitry at the output, but the issue persists. So this one’s on the shelf until we figure it out.
• https://iffybooks.net/pico-sampler
• https://iffybooks.net/pico-mp3-sampler-files.zip
• https://iffybooks.net/pico-sampler-code.py.txt
Pico LED Hourglass
After a few iterations we’ve settled on a programmable hourglass project with 6 LED lights, a vibration motor, and a push button switch, all soldered to a Pi Pico. Pressing the button starts a timer that runs for whatever duration you choose. I’ve been using mine for writing sessions!
• https://iffybooks.net/pico-hourglass
• https://iffybooks.net/pico-hourglass-code.py.txt
Pico Power Cycler
Another beginner soldering project using a Pi Pico. We designed this kit to reboot solar-powered LoRa radios, which sometimes crash due to voltage fluctuations. But you can use it to turn any USB-powered device on and off, like a fan or a string of holiday lights.
• https://iffybooks.net/pico-power-cycler
• https://github.com/iffybooks/pico-power-cycler
Python Script-Along: Download Podcasts to an MP3 Player
Leaving home without a phone is in fashion, but it’s nice to have something to listen to while you’re waiting for the bus. In this beginner-friendly workshop we write a Python script that downloads new podcast episodes directly to an MP3 player (or your computer if you don’t have one). We’re planning to run it again!
• Download_Podcasts_to_an_MP3_player.py.txt
Security Culture Zine Pack
A collection of 84 zines on security culture and related topics, which we originally distributed on USB flash drives.
Soldering Workshops: LED hearts, audio meters, FM transmitters, etc.
We expanded our soldering curriculum in 2025, cycling through projects at varying difficulty levels so folks could come back and keep practicing. Our most popular project was one of the trickier ones, a heart-shaped circuit board with 22 LEDs and an oscillator circuit that takes 2–3 hours to complete. We’ll be running it again in late January/early February!
• https://iffybooks.net/heart-led-soldering-kit
Thrash Bot Workshop
A servo motor on a cardboard stand that you can program to strum/thwack the strings of a guitar. What’s not to like? These workshops were lightly attended, but all the parts are still in stock if you want to make one.
• https://iffybooks.net/thrash-bot
• https://iffybooks.net/thrash-bot-code.py.txt
USB Data Blocker Workshop
For this workshop we made a USB adapter that lets power through but not data, intended to prevent leaking metadata/files when connecting to public charging stations. But new phones are getting fussy about their power needs, and the hardware we’ve been using apparently has too much resistance. Back to the drawing board.
Zine Vending Machine Web App
A friendly web interface for printing zines from our PDF library, built using the Flask web app framework. I’m the only one using it so far, but at some point I’ll write instructions so visitors can print out-of-stock zines.
Wave Craft: Music Box Spectrogram
A workshop on making the leap from visualizing audio in the time domain (the waveform shape you’ve seen in audio editing programs) to the time-frequency domain (the spectrogram, which looks more like a heat map). We start the session by recording a music box using Audacity and exporting the audio to a WAV file. Then we open the file in Sonic Visualiser, navigate around its spectrogram, and talk about what it all means.
• Wave_Lab_Music_Box_Spectrogram_SCREEN_Iffy_Books.pdf
• Wave_Lab_Music_Box_Spectrogram_IMPOSED_Iffy_Books.pdf
Wi-Fi Tricks with Ghost ESP
Ghost ESP is software for wi-fi and Bluetooth scanning designed to run on inexpensive microcontrollers like the ESP32-C3. But between the first and second time we offered the workshop, something changed in the Ghost ESP codebase and it stopped working entirely on our boards. If it gets resolved we may offer it again!
• https://iffybooks.net/Ghost_ESP_Zine_Iffy_Books.pdf
As usual, y’all are free to print, re-post, edit, and otherwise do whatever you want with the materials here. No permission needed for anything. But we’re always glad to hear from people who find these resources helpful!
If you’re a Patreon supporter, thank you so, so much for helping make Iffy Books happen. We’re in better shape financially than we were a year ago, and we’re on our way to being actually sustainable. But I’m feeling some pressure to step up sales and/or fundraising in the coming months to keep things on track. I’m still passionately devoted to what we’re doing at the shop and I’m confident we can keep it together.
So consider joining our Patreon. If you’re a supporter already and you feel moved to increase your donation, we won’t dissuade you.
In addition to supporting the work above, your donations make it possible for these groups to meet regularly:
• Anarchist Sewing Club
• FAFIO Meetup (F_ck Around and Figure It Out)
• IndieWeb Homebrew Website Club
• Intelligence History Reading Group
• Make Your First Website Class
• Neo-Luddite Reading Group
• Permacomputing + Solarpunk Meetup
• Philly 2600 Hacker Meetup
• Speculative Futures Reading Group
• The Writing Room
Happy new year! And other holidays too! Hope to see you at the shop soon!
—
Steve McLaughlin
Iffy Books
404 S. 20th St., PHL
https://iffybooks.net