The Swift Caller Project
The Swift Caller is more than just an automated playback system—it’s a grassroots rescue mission for one of our most incredible migratory birds.
This project has incredibly humble beginnings. Born from a collaboration between Draco, the Sanquhar Men's Shed, and swift enthusiast Andrew Turney, it started with a shared frustration: everyday people wanting to help Swifts were getting absolutely ripped off by ridiculously overcharged commercial audio lures. We knew we could build something better, smarter, and radically more accessible for the community.
We are tackling this with TWO distinct approaches:
The "Install and Forget" Full Unit (Our 2026 Focus): Designed for immediate, rugged field use, this fully assembled unit is solar-powered and completely autonomous. Optimized to project high-fidelity calls for 6 hours a day (with a massive 18-hour reserve capacity), you simply mount it at the start of the season in May and let it run flawlessly without maintenance until the birds migrate.
The "Click & Connect" Development Kit (Target: 2027): We are actively developing a modular, no-solder kit so other Men's Sheds and hobbyists can build their own callers. However, we refuse to release a product that isn't bulletproof. We are dedicating the entire 2026 season to gathering rigorous field feedback from our Full Units first, ensuring the Dev Kit is perfected for a 2027 rollout!
Featured in The Scottish Shedder Magazine
The Swift Caller project recently caught the attention of the Scottish Men's Sheds Association!
We are thrilled to be featured in the February 2026 edition of the magazine under the headline:
"Sanquhar Shed acts swiftly to save the birds."
Head over to Page 24 to read the full article covering our intergenerational collaboration, the technical hurdles, and our ultimate goal of building a network across Scotland.
Why choose the Swift Caller?
Powered by the Sun
It runs completely off its own solar panel and built-in battery. The smart power management means it keeps calling the birds even during those long, cloudy Scottish weeks.
Install & Forget
It knows when to wake up. The caller turns itself on at sunrise and goes to sleep at sunset. Once it's mounted, you don't need to touch a thing all season.
Crystal Clear Sound
Swifts are picky listeners. We use a high-quality audio setup to play their calls exactly as they sound in the wild, ensuring the birds actually respond.
Never Needs Plugging In
Designed to sip power. The "brain" inside the unit takes deep 'micro-naps' between calls, saving enough energy to run flawlessly all summer long.
Scottish Weatherproof
Built to handle heavy rain, morning frost, and summer sun. The tough, fully sealed casing keeps the electronics safe and dry all year round.
Built to Last & Easy to Fix
Instead of throwing it away if a part wears out down the line, our design lets anyone swap out a battery or speaker in minutes.
How to Order / Get Involved
Full Unit
Alpha Version 1
£35
/Unit
Limited Technical Support
Standard Firmware (No Custom Mods)
Weatherproof & Outdoor Tested
Available March 2026
Made to order
Development Kit
Alpha Version 1
TBD
/Unit
Full Technical Support
Software Customization Support
Indoor tested only.
Delayed until 2027
Delayed until 2027 so that we can focus on the main unit this year, as the full unit is a ready-to-go solution!
Interested in obtaining a unit?
As we are currently in the Alpha Phase of development, we are not yet accepting automated online orders. However, we are building units manually to order for local community groups and individuals.
Visit Us
Sanquhar & District Men's Shed
St Brides Church Hall,
St. Mary's Street
Sanquhar
DG4 6BW
Shed Opening Hours
| Day | Time |
|---|---|
| Monday | 10:00am - 12:00pm |
| Wednesday | 10:00am - 12:00pm & 7pm - 9pm |
| Friday | 10:00am - 12:00pm |
Resources & Downloads
The Mission & The Story
The Spark: It all began when fellow Shed member Andy Williamson attended a talk by swift enthusiast Andrew Turney.
Inspired by the plight of the Swift, a bird that travels an astonishing 7,000 miles from Africa only to find its UK nesting sites disappearing rapidly,
he realized that while the Shed had the woodworking skills to build the nest boxes, we needed a way to actually attract the birds to them.
I joined the Shed in May 2025, and one of my first projects was an electronic "Days Since Last Accident" sign to help keep the workshop safe.
Seeing this, Andy approached me to ask if we could work together to design a new 'Swift Caller'—one that would not require expensive equipment or mains power, but could be deployed anywhere using just the sun.
Intergenerational Innovation: This project became a perfect example of how our Shed works. While Andy led the construction of the wooden nesting boxes, the technical challenge fell to me. My goal was to design an electronic caller that could mimic the "screaming" calls of Swifts to encourage them to investigate new sites. But it couldn't just be a simple radio transmitter or a standard Bluetooth speaker; we needed an intelligent device that could manage its own audio schedules, survive the Scottish weather, and run all summer without needing constant maintenance.
The Solution:
Drawing on the need for simplicity, I wanted to move away from complex wiring and maintenance. I developed an "Install and Forget" system: once you mount the unit, it runs autonomously based on the pre-programmed schedule.
At the heart of the unit is my custom SC-MPU (Swift Caller-Main Processing Unit), powered by an ESP32-C3.
To make this accessible to other groups, I also developed a companion "Click & Connect" Development Kit. This allows other Sheds to assemble their own units using just a screwdriver—no soldering required.
Looking Ahead: With Swifts returning in May, the race is on. Our goal is to have the first batch of units and Developer Kits ready for our annual coffee morning. By making the technology accessible, I hope to help reverse the decline of these extraordinary birds. As I mentioned to the Scottish Men’s Sheds Association recently: "The caller can actually be adapted for use with other bird species too," making this a versatile tool for future conservation efforts.
SC-MPU Tech Specs
Core Microprocessor: ESP32-C3
Power Module: TP4056 5V
Audio AMP: MAX98357 Amp (Mono)
MPU Housing Material: PETG Plastic
Wiring: 20 AWG
Other Tech Specs
Power input: USB/5V Solar/18650 Li-Ion
Speaker: 2831 4-ohm 3W Speaker
Full Unit Material: ABS Plastic
Big Thank You
This project wouldn't be possible without the help of:
- Will: For 3D printing the very first V1 prototype case when I was just getting started.
- Alex: My loving partner who has been a constant source of motivation.
- Neil: Donation of 18650 Batteries, Document reading and project support.
- Andy: For the original idea and leading the nesting box build.
- Andrew: For the swift knowledge and practical field experience.
- Sanquhar Men's Shed: For the funding, tea, and endless support.
Project FAQ & Insights
Development Roadmap
Inception & Early Prototypes
Sparked by a conversation with Andy Williamson, the goal was set to build a solar-powered Swift Caller to pair with the Shed's nesting boxes. We benchmarked microcontrollers, settling on the highly efficient ESP32-C3 paired with a MAX98357 I2S amplifier. By Autumn, the first V1 physical prototypes were being 3D-printed in PLA.
Summer & Autumn 2025
The "Soak Test" & The Glenkens Meeting
Met with swift enthusiast Andrew Turney, who gave the project an enthusiastic green light, cementing our decision to design a "Click & Connect" system.
However, winter field testing revealed a major flaw: the PLA plastic casing degraded and warped under heavy Scottish rain.
The Pivot: Production was immediately shifted to weather-resistant PETG and ABS materials, and the Sanquhar Committee officially approved the £35 pricing model.
Winter 2025 / 2026
Alpha Production Run
Overcoming a two-week shipping delay on Li-Ion cells, the initial production run for the Sanquhar Men's Shed began. Cases were printed, components were soldered, and the first batch of fully sealed units was assembled.
March 2026
Deployment & Firmware V002
A massive month for the project! We successfully delivered a batch of black A1 units to Andrew Turney for specialized conservation field testing. Simultaneously, the green Shed unit was mounted on the stone walls of St. Brides Church Hall.
Firmware V002: a major firmware update introducing Light Sleep overnight hibernation, drastically improving battery life, alongside a massive overhaul of the Web UI with uptime tracking, volume sliders, and dynamic CPU scaling.
April 2026 (Current)
Active Field Testing Season
The Birds Return. The callers will run autonomously throughout the summer. This season is strictly dedicated to gathering data on unit stability, solar efficiency, and bird interaction rates across the Sanquhar and other testing sites.
May - August 2026
DEVKET-1 Public Launch
Using the data and firmware stability achieved during the 2026 test season, the modular "Click & Connect" Development Kits are targeted to officially launch, allowing other Men's Sheds across Scotland to easily build their own callers.
Early 2027
About Me
I'm Draco, a passionate developer focused on creating innovative and enjoyable projects. Let's connect and collaborate!
Contact
© 2011 - 2026 Draco. All rights reserved.