Optical Networks

IoT in a fiber of Light: 1-Fiber and the Free Networks

By Nissan - Sergio Sorrenti •
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IoT in a fiber of Light: 1-Fiber and the Free Networks

Where silicon archaeology meets the patient mathematics of light through plastic

The October heat pressed against Barcelona’s concrete with the persistence of accumulated memory. Adrià Montserrat climbed four flights of narrow stairs in the Gràcia building, his messenger bag bouncing against his hip with each step. Through the stairwell’s grimy windows, the city’s digital nervous system hummed invisibly—fiber optic cables threading through subway tunnels, data centers cooling in hidden basements, the electromagnetic symphony of eight million connected souls.

On the second floor landing, Esperanza Vidal intercepted him with the focused determination of someone who had been waiting. Her weathered hands cradled something small and metallic like a talisman that had lost its power.

“Adrià, you understand computers and electronics, verdad? This thing”—she held up the small metallic disk—“it opened my garage for fifteen years. Now, nothing. The technician wants four hundred euros for a new system.” Her voice carried the particular frustration of someone who had survived Franco’s bureaucracy only to find herself defeated by digital locks.

Under the stairwell’s fluorescent light, he examined the device. A stainless steel button with the same shape just more larger of a watch battery. A microscopic chip visible through its transparent window, the laser-etched logo read “Dallas Semiconductor”—Silicon Valley archaeology embedded in Spanish suburban reality.

“An iButton,” he murmured. “DS1990A, most likely. Haven’t seen these in years.”

“Claro, that’s what the locksmith called it. But you can fix it, no? You always solve these problems.” Something in her tone suggested more than confidence in his technical abilities—a kind of faith that implied she understood the intersection of human ingenuity and stubborn machinery better than she revealed.

Twenty minutes later, in his workshop above, Esperanza’s garage key had become the catalyst for something entirely unexpected.

The Archaeology of Forgotten Protocols

The oscilloscope painted familiar patterns across its phosphor screen. Reset pulse, presence detect, ROM read. The iButton responded perfectly—electronically intact after fifteen years of Mediterranean weather and mechanical stress. The problem lived in the garage controller’s failing memory, not the device itself.

But as Adrià watched the hexadecimal sequence scroll across his terminal—01 A2 B3 C4 D5 E6 F7 01—a half-remembered fragment of digital history stirred in his consciousness. Something about 1-Wire networks and the early internet. Something archived in the depths of hacker folklore.

His browser opened to Hackaday’s familiar interface, search terms appearing as if typed by archaeological instinct: 1-wire network router.

The first result was digital archaeology itself.

“1-Wire Wireless Router”
March 10, 2006

1-Wire is a low speed communications bus. OWFS is the 1-wire filesystem for Linux. Combine the two with a WRT54G and you’ve got a cheap wired/wireless network enabled data collection platform…

OWFS. The 1-Wire File System. Adrià had forgotten this existed—a Linux kernel module that made every 1-Wire device appear as a simple file in the filesystem. /mnt/1wire/10.A2B3C4D5E6F7/temperature to read a sensor. /mnt/1wire/family/ to enumerate devices by type. The humble WRT54G router, running OpenWrt, suddenly transformed into a wireless hub for an entire network of sensors.

Nineteen years ago, someone had already solved part of the democratization puzzle. Every 1-Wire device accessible through a simple web interface. Temperature sensors in attics appearing as clickable links. Door switches reporting their state through HTTP requests. The poetry of making silicon speak the language of the early web.

But they were still bound by copper’s fundamental limitations—shared bus architecture, limited range, electrical interference.

The next result made his breath catch.

“IPv6 To 1-wire Protocol Translator”
December 2, 2009

[Fli] assembled an AVR based system that can assign IPv6 addresses to 1-wire components. An AVR ATmega644 microcontroller is used in conjunction with an ENC28J60 ethernet controller chip…

Frederik Lindberg had seen the mathematical poetry hiding in plain sight. A 1-Wire device’s sixty-four bit unique identifier mapped perfectly to the sixty-four bit host portion of an IPv6 address. One device, one globally unique internet identity.

Not just network-accessible through a hub router—individually addressable across the entire internet. Each temperature sensor carrying its own unchangeable name in the vast namespace of IPv6. The hub would discover devices through standard 1-Wire polling, then assign IPv6 addresses based on their eternal ROM codes. No configuration required. No central authority beyond the local gateway.

The historical progression was breathtaking. 2006: OWFS turning commodity routers into 1-Wire hubs. 2009: IPv6 giving every device its own internet identity through intelligent mapping. 2025: The obvious next step that somehow nobody had taken.

The Catalyst: Plastic Optical Fiber

Adrià leaned back in his chair, feeling the particular vertigo that accompanies the discovery of an idea whose time has finally arrived. Esperanza’s iButton—this small token of technological frustration—suddenly represented more than a garage door key. It was a fragment of a distributed future that had been waiting two decades for the right physical medium.

Three generations of hackers, each building on the last. The OpenWrt enthusiasts making sensors wireless through radio. Frederik mapping silicon identities to cyberspace. And now, perhaps, the moment to free the protocol itself from copper’s electrical tyranny.

1-Wire was philosophically perfect. A single data line plus ground. Robust enough to function over tens of meters of twisted pair in electrically hostile environments. The killer feature was those eternal sixty-four bit identities—globally unique, factory-burned, unchangeable. Dallas Semiconductor had created a distributed addressing system that predated the modern internet by decades.

The limitation was physics. Capacitance, resistance, electromagnetic interference. Engineering could optimize, but couldn’t transcend the fundamental constraints of electrical signaling through metal conductors.

But light traveled differently.

The synthesis crystallized with mathematical precision: 1-Fiber. Not a new protocol, but 1-Wire liberated from its physical constraints. The same elegant timing, the same robust addressing, the same parasitic power architecture—but carried by photons through plastic optical fiber instead of electrons through copper.

His eyes fell on the tangled collection of audio cables beneath his workbench. Toslink. Digital audio cables. Red-glowing plastic optical fiber that had carried music between CD players and amplifiers for decades. Six-hundred-fifty nanometer wavelengths dancing through polymer cores, already optimized for the exact specifications 1-Fiber would require.

The infrastructure was already there, disguised as consumer audio equipment.

From Copper to Light: The Elegant Solution

The breakthrough came not from complex engineering, but from observing the simplest possible solution hiding in plain sight. Among the audio cables lay a Y-shaped Toslink splitter—one input, two outputs. The kind of unremarkable plastic component that cost a few euros and was designed to split digital audio signals to multiple amplifiers.

But light was light, whether carrying Dolby Digital or 1-Wire protocols.

The genius was mechanical, not electronic. Two separate optical paths converging into a single fiber. One path for the LED transmitter, one path for the photodiode receiver. The splitter handled the optical switching with pure physics—no active components, no power consumption, no complexity beyond the geometry of refraction.

LED on one arm, photodiode on the other, device connected to the single output. The timing protocols remained identical to electrical 1-Wire. Master transmit phase, device respond phase, all preserved through half-duplex operation. The splitter was transparent to the protocol, invisible to the devices.

His first experiments used components from the salvage drawer. A 650nm LED extracted from a broken indicator panel. A PIN photodiode carefully desoldered from an optical mouse assembly. Simple driver circuits—a transistor for the LED, a comparator for the photodiode. The electronics were almost trivial compared to the optical elegance.

Range testing through standard Toslink cable revealed ranges approaching fifty meters. Clean, reliable, interference-free transmission. The polymer fiber could be bent like garden hose, pulled through walls like speaker wire, spliced with simple mechanical connectors available at any electronics shop.

The economics were more nuanced than simple cost calculations. Individual components from electronics shops inflated prices dramatically. AliExpress sourcing in reasonable quantities brought LED and photodiode costs to under two euros total. For makers willing to order components by the hundred from Taiwanese suppliers through GlobalSources, the economics shifted toward manufacturing reality—essentially negligible component costs.

But the deeper revolution was philosophical, not economic.

Engineering the Democratic Revolution

The beauty of the Y-splitter approach lay in its complete passivity. No switching circuits, no timing dependencies, no active components to fail. The optical domain handled bidirectional communication through pure geometry. During transmission, the LED illuminated both the receiver path (harmlessly) and the device path (carrying data). During reception, incoming light illuminated both the transmitter path (harmlessly) and the receiver photodiode (recovering data).

Power loss was the only trade-off. Each passage through the splitter cost approximately 3dB—half the optical power lost in each direction. For the modest timing requirements of 1-Wire at 15 kilohertz, this loss budget remained entirely manageable over practical distances.

The mechanical implementation crystallized around Toslink panel-mount connectors oriented at ninety degrees to the PCB surface. LED and photodiode mounted directly behind the connector ferrules, aligned to the one-millimeter POF core with mechanical precision. The connector became both the optical interface and the mounting mechanism.

For extended range applications, dual-fiber differential signaling remained possible. Two Y-splitters, four optical paths, RS-485 transceivers driving the transmit LEDs differentially. Common-mode noise rejection through optical channels instead of electrical. The range could extend beyond a hundred meters while maintaining complete electrical isolation.

The Network Awakens: Mapping Silicon to Cyberspace

Late that night, with Barcelona settling into its digital evening rhythm, Adrià began implementing Frederik Lindberg’s vision through optical channels. Each 1-Fiber device would maintain its factory-burned 64-bit identity, ready to be mapped to IPv6 addresses by a network hub.

The hub would discover devices through standard 1-Wire polling over optical links, then assign IPv6 addresses based on their eternal ROM codes:

2001:db8:1::/64::01a2:b3c4:d5e6:f701

No device configuration required. No central authority beyond the local gateway. Just the elegant mathematics of distributed addressing working exactly as Frederik had envisioned—the hub handling IPv6 translation while preserving each device’s unique silicon identity.

Optical splitters enabled star topologies impossible with electrical systems. One master node could communicate with dozens of sensors through passive fiber distribution—no active electronics in harsh environments, no single points of failure. The polymer fibers could run through cable trays, conduits, or simply be stapled along walls like low-voltage speaker wire.

For permanent installations, wall outlets emerged as the logical architecture. Small plastic boxes with Toslink jacks on the front, mechanical fiber connectors on the back. Bulk POF cable between outlets, short Toslink patch cables to devices. The installation philosophy mirrored ethernet networking—permanent backbone infrastructure with flexible access points.

His first complete 1-Fiber network spanned the workshop like a constellation of red-glowing connections. Five salvaged 1-Wire devices connected through optical splitters and Toslink cables, each device announcing its identity through precisely timed light pulses.

The demonstration was simple but profound. A DS18B20 temperature sensor, thirty meters away through three fiber segments, reporting its measurements to an IPv6 address derived from its eternal sixty-four bit identity. The same sensor that would have required careful electrical design and EMI shielding now worked flawlessly through optical isolation.

No configuration. No device drivers. No proprietary software. Just standard 1-Wire protocols flowing through light instead of electrons, carrying Dallas Semiconductor’s vision of uniquely addressed silicon into the photonic age.

The Philosophical Architecture

As morning approached, Adrià found himself contemplating the deeper implications. Technology as archaeology of the future. 1-Wire had been waiting thirty years for the right physical medium. IPv6 had been waiting twenty years for devices worth addressing individually. Toslink cables had been waiting for applications that needed their unique properties of electrical isolation and electromagnetic immunity.

The synthesis felt less like invention than discovery. Three generations of engineers, each solving part of a larger puzzle without seeing the complete picture. OWFS making 1-Wire networkable. IPv6 giving every device its own internet identity. Toslink providing the democratic optical infrastructure.

Free software principles demanded that 1-Fiber remain democratic technology. GPL version three licensing for all software implementations. Creative Commons licensing for hardware designs. No proprietary modulation schemes, no vendor lock-in, no artificial scarcity. Just the patient physics of coherent light carrying digital truth through plastic polymer cores.

The revolution would be photonic, and it would be free.

Esperanza’s Revelation

Three days later, Esperanza’s garage door opened smoothly to her re-enrolled iButton. But she noticed the thin red cable snaking from Adrià’s workshop window to the building’s utility room—a prototype 1-Fiber link monitoring temperature sensors throughout the old structure.

“Qué interesante,” she murmured, watching the faint red glow pulse through the translucent cable. “Light carrying information. Like the old lighthouse signals, but inside a thread.”

She understood intuitively what many engineers missed—that the real breakthrough wasn’t technical but philosophical. The liberation of information from the constraints of metal and electricity. Data flowing as light, as free and fast as thought itself.

“When I was young,” she continued, “we sent messages by hiding them in books, in songs, in the way we hung laundry. Now you hide networks in audio cables. Siempre the same—intelligence finding its own path, no matter what walls they build.”

Adrià realized she was right. 1-Fiber wasn’t just an engineering improvement—it was the digital equivalent of guerrilla communication, networks that could route around damage, censorship, and corporate control by speaking the language of light through infrastructure designed for entertainment.

The Propagation Begins

Word spread through the networks where real innovation flows—forums buried in internet backchannel traffic, mailing lists maintained by volunteers, IRC channels where knowledge moves at light speed between minds ready to receive it.

The documentation, released under the GNU Free Documentation License, sparked a global wave of grassroots innovation. Each new deployment reinforced the core idea: technology becomes truly powerful when its knowledge is shared openly and adapted locally.

From Nairobi: “Used recycled fiber from old car audio systems and 3D-printed splitters to connect community weather stations. Now farmers in the Rift Valley receive real-time alerts via SMS—no more relying on unreliable radio broadcasts.”

From Lima: “Repurposed POF cables from decommissioned arcades to create a mesh network in the barrio. The city’s electrical grid is unstable, but light doesn’t care about power cuts. Our sensors keep running even during blackouts.”

From Jakarta: “Local hackerspaces turned discarded karaoke machine cables into 1-Fiber links for flood warning systems. Students soldered transceivers in weekend workshops—now the whole neighborhood gets alerts before the rivers rise.”

From Athens: “In abandoned buildings turned into maker labs, we used POF from old DVD players to network DIY air quality monitors. The city won’t fund our projects, but we don’t need their permission to breathe cleaner air.”

From Mumbai: “Rickshaw drivers now carry POF toolkits to splice cables on the go. We trained them to connect street vendor stalls to a shared inventory system—no more lost sales because of stockouts. Technology should work for people, not the other way around.”

Every story proved the same truth: democratic technology doesn’t need Silicon Valley’s blessing. It thrives in garages, alleys, and classrooms, built from scrap and stubborn optimism. Whether it’s plastic fiber for local connections or glass fiber for longer reach, the future is built one photon—and one community—at a time.

Technical Implementation: Engineering Light for Democracy

The complete 1-Fiber system preserves every aspect of the original 1-Wire protocol while transcending copper’s physical limitations. Standard timing specifications remain unchanged—fifteen kilohertz signaling rate, four-hundred-eighty microsecond reset pulses, sixty microsecond time slots. This backward compatibility ensures that existing 1-Wire devices work transparently over optical links through simple electrical-to-optical translation.

The core innovation lies in the Y-shaped Toslink splitter architecture. This passive optical component enables bidirectional communication over a single fiber without any active switching electronics. LED and photodiode connect to separate arms of the splitter, while the device connects to the common output. Optical power loss of approximately 3dB per direction represents the only system trade-off, easily manageable within 1-Wire’s modest timing requirements.

Component sourcing reflects the maker reality spectrum. Electronic waste harvesting enables near-zero cost for those with salvaging skills. AliExpress purchasing in reasonable quantities brings component costs to under five euros for a complete transceiver. For production-oriented makers sourcing components by the hundred from Taiwanese suppliers, the economics approach manufacturing reality with essentially negligible material costs.

Plastic Optical Fiber implementations use precisely 650 nanometers for optimal transmission through PMMA polymer cores. Standard Toslink cables provide the democratic infrastructure—one-millimeter diameter POF that can be bent, twisted, and pulled through walls like audio cable. Installation requires no special skills beyond basic connector handling, and mechanical splicing can be accomplished with simple tools available at any electronics retailer.

Transmission ranges extend to fifty meters per fiber segment using salvaged LED and photodiode components. Extended-range implementations using differential optical signaling can achieve over 125 meters through dual Y-splitter architectures with RS-485 interface compatibility. The plastic fiber’s immunity to electromagnetic interference and electrical isolation eliminates entire categories of installation problems that plague copper networks.

Network discovery protocols operate identically to copper-based 1-Wire systems. Hub nodes poll the optical environment using standard ROM search algorithms, automatically building IPv6 routing tables based on discovered device identities. Each device’s factory-programmed sixty-four bit address becomes its globally unique internet identifier through hub-managed mapping to IPv6 host addresses—no device configuration, no translation complexity, no central authority beyond the local gateway.

Installation architecture scales from point-to-point connections to building-wide infrastructure. Wall outlet systems using Toslink jacks and bulk POF cable enable permanent installations with professional appearance. The mechanical implementation uses Toslink panel-mount connectors oriented at ninety degrees to PCB surfaces, with LED and photodiode positioned directly behind the connector ferrules for optimal optical coupling to the one-millimeter POF core.

The libre hardware specification ensures perpetual maintainability. All mechanical designs carry Creative Commons BY-SA licensing, electronic schematics use CERN Open Hardware License version two, software implementations follow GNU General Public License version three. No vendor lock-in, no planned obsolescence, no artificial scarcity. Just patient engineering documented for democratic reproduction across all economic levels.

Global deployment scenarios range from industrial sensor networks in electromagnetically hostile environments to community mesh networks that route around expensive telecommunications infrastructure. Emergency communication systems can maintain operation through electromagnetic disruption that would destroy radio links. Urban installations connect buildings through optical fiber runs that require no electrical permits or utility coordination.

The technology scales from single-device demonstrations to city-wide networks limited only by the mathematics of optical propagation and the creativity of community implementers. Each successful deployment validates the thesis that technological sophistication can be democratized through principled sharing of knowledge and honest documentation of implementation realities across all economic levels.

PS: The people involved in this story may be inspired by real individuals or archetypes, but are products of the imagination of this blog post’s author.

References & Technical Documentation

Historical 1-Wire Network Projects

Plastic Optical Fiber Technology

1-Wire Protocol Documentation

IPv6 Addressing and Implementation

OpenWrt and Embedded Linux

  • “OpenWrt Project Documentation”
    Community-driven router firmware enabling custom applications
    https://openwrt.org/

  • “OWFS - One Wire File System”
    Linux kernel module for 1-Wire device access
    https://owfs.org/

Libre Hardware Philosophy and Licensing

DIY Optical Cable Construction

Component Sourcing and Electronics Recycling

  • “Electronic Component Recovery and Reuse”
    Guidelines for salvaging usable components from electronic waste
    https://www.epa.gov/recycle/electronics-donation-and-recycling

  • “LED and Photodiode Specifications for Optical Communication”
    Technical data for 650nm optical components
    Available through component manufacturer datasheets

Industrial and Automotive POF Applications

Light finds its own path into the infrastructure where copper was used before, a quiet revolution one photon at a time.