DRAFT · SPECULATIVE
Pop Boll Developer Specifications
Version 1.0-draft · Status: speculative draft · Updated 2026-11-08
Speculative draft. No Pop Boll hardware has shipped, and nothing on these pages has been built or validated on hardware. Dimensions, pinouts and protocols will change without notice, and nothing here is an offer, a commitment or a promise of compatibility. We would love to hear about partnership, OEM and dev-kit ideas: use the contact form below.
These pages are for people who want to build things for the Pop Boll: docks, speakers, light pucks, charging stands, cartridge computers, and software that changes how the Boll writes songs. They are open specifications. You do not need our permission, a licence fee or a certification to build to them.
What the Pop Boll is#
The Pop Boll is a soft, glowing ball, 135 mm across, with a tiny band inside. Sixteen virtual musicians jam, seven judges score every take, and together they write and play pop songs, learning from licensed song collections called corpora.
- It works offline. Everything the band needs runs inside the ball. A Boll that has never been online makes songs exactly like one that has. When it is online, it fetches new corpora and uploads the songs it made.
- It lights up. A ring of 24 LEDs shows each musician in their own colour, in time with the music.
- It has a front panel, the medallion, with three buttons, a USB-C port and a 3.5 mm audio output.
- It has a dock foot. The bottom of the ball is a rigid, keyed, magnetic connector: the female half of the Bollard interface.
Bollard and bollardeck#
Bollard is the open ecosystem of docks and accessories that attach to the bottom of the Boll, and the interface they share. A Bollard dock mates with the Boll's foot through a 3.5 mm plug, a USB-C plug and a row of 10 spring pins, all hidden inside a spring piston until a Boll is pressed onto it. The Bollard Physical Specification fixes every dimension, pin and power rule. Everything else about your dock is up to you.
bollardeck is the API that docks, cartridges and routines speak. Docks and cartridges exchange JSON messages with the Boll over USB or Bluetooth Low Energy: they can read what is playing, the song's MIDI stems, the beat, the light frames and the buttons, and they can send volume, transport, remix, audio-routing and light-sync requests. Routines are small Python programs that hook into the Boll's song factory on your own Boll. The bollardeck API covers all three.
Device classes#
| Class | What it is | Interface | Read |
|---|---|---|---|
| Bollard docks | anything that mates with the Boll's foot: speakers, amps, charging stands, light bases, toys. Docks on one of four profiles (Full, Lite, USB-C, Passive) use more or fewer of the foot's features | Bollard, one profile | Bollard §3 |
| Pucks | stackable Full-profile docks with a male top and a female bottom, Ø 135 or Ø 72 mm, in 25 mm height steps. Up to 5 stack under one Boll, in any order | Bollard Full | Bollard §16 |
| Bolltridges | cartridges with their own Linux computer running one signed image: a synth, a sequencer, a soundfont pack, an effect, a player, a remixer or a visualiser. Up to 4 chain under one Boll, and each powers itself | Bollard Full or USB-C, plus bollardeck Part C | Bollard §17 and bollardeck Part C |
| The Boll Cap | the free cap that ships on every Boll: a passive pass-through that brings the foot's USB-C and 3.5 mm out to the side, so the Boll sits flat while charging or feeding speakers. The zero-feature reference device | Bollard Passive | Bollard §18 |
| Wireless accessories | anything that talks to the Boll over Bluetooth Low Energy with no physical connection | bollardeck over BLE | bollardeck §3 |
| Routines | software only: Python hooks into the song factory that run on your own Boll | bollardeck Part B | bollardeck Part B |
| PWHAMSS devices | devices a person works on alongside the band: a Workshop, context-switching keys and a Bolltridge inside, all drawing one frame. The first is the Glass Snipler | Bollawax inside, bollardeck Part C to the core | PWHAMSS and the Glass Snipler |
PWHAMSS and the Glass Snipler#
The Boll plays by itself. PWHAMSS (Personal Workshop for Human-Device Animation and MIDI Sync Systems) is the family of Pop Boll devices where a person works alongside the band instead: the same Bollawax engine, the same sixteen musicians and seven judges, the same licensed corpora, with a person at the keys pulling material out of songs, cutting it and handing it back. Every PWHAMSS device keeps an always-visible Workshop, keys that redraw their legends with the mode, a frame that every screen and light draws from, and a personal library that follows the person through HAMS sync. The PWHAMSS page states those principles, the event and frame contract, and the roadmap.
The Glass Snipler is the first PWHAMSS device: a slab about 12 × 8 inches with a 12 × 3.5 inch touch Workshop, four knobs (Small, Medium, Large, Huge), a touch pad over a 16 × 26 RGB matrix, four mode diamonds (K, P, S, A), 48 transparent pressure-sensitive keys over an LCD and six side keys. Everything you make on it is a sniplet (a stem, a riff, a loop, a beat or a macro); SNIP POP lifts material off the Workshop and SNIP PUT drops it back; the band listens to what you cue and may steal finished public sniplets into its own riff books. Inside, the Boll's own core runs Bollawax and a Raspberry Pi acts as a Bolltridge running the bollawax-snipler image. The Glass Snipler page has the layout, the key maps, the sniplet format and what is not decided.
Neither device exists in hardware. The design is being built first as a web simulator at popboll.com/pwhamss, open to superusers during development, that runs the same state machine the slab will.
The interface at a glance#
| Item | Value |
|---|---|
| Connectors | 3.5 mm TRS + USB-C + BCR-10 (10 spring pins in a straight row at 2.54 mm pitch), all on one floating plate inside a spring piston |
| The Boll's side (female) | a 3.5 mm jack, a USB-C receptacle and 10 hard-gold pads in the floor of a well in the foot; 4 magnets (S pole down); a key pocket at the front |
| Reference plane | Datum A, the Boll's rigid foot face. The pad plane is 7.5 mm above it |
| Piston | Ø 41.5 mm, 15 mm travel, extended face 22.0 mm above Datum A |
| Spring pins | free tips 8.2 mm above Datum A, so 0.7 mm of compression on the pads |
| Profiles | Full (everything), Lite (4 pins, no USB), USB-C (USB only), Passive (audio and power only) |
| Power into the Boll | USB-C VBUS at 5 V, up to 3 A (Full, USB-C, Passive), or V_AUX at 5 V, up to 2 A (Lite) |
| Power from the Boll | none on its foot; at most 5 V / 1.5 A, on its medallion USB-C port only |
| Stack power | V_STACK, 10–17 V, 4 A for the whole stack (Full profile; the Boll does not connect to it) |
| Audio | A-BUS analog line, 1.0 Vrms at 0 dBFS, wired through every module; USB Audio Class 2 optional |
| USB roles | the Boll is always the USB host (it takes the role by a USB PD data-role swap) and only ever sinks power on its foot |
| Identity | Full: an I2C header (magic BLD1) and a JSON descriptor; Lite: the same header over 1-Wire; USB-C: USB descriptors and the bollardeck hello |
| Sync | a hardware SYNC pin: 60 Hz frame ticks, 2 ms beat pulses, 4 ms downbeat pulses |
| Module sizes | Full Ø 135 mm, Mini Ø 72 mm; heights in 25 mm steps, at least 50 mm |
| Stacks | up to 5 modules plus the Boll above any base, with a static tip angle of at least 12° |
| API | bollardeck/1: JSON Lines over USB CDC-ACM (interface string bollardeck) or BLE GATT |
| Cartridges | at most 4 Bolltridges per Boll; signed images only, except in hacker mode on the owner's own Boll |
The specifications#
- Bollard Physical Specification, version 1.0-draft, for hardware developers: datums and dimensions, the floating plate and piston, the BCR-10 pins and pinout, power, USB-C roles, analog audio, enumeration, sync, profiles, stacking, the Bolltridge device class, the Boll Cap, the Reference Bollard speaker design, hobbyist builds and the conformance checklist.
- bollardeck API, version 0.1-draft, for software developers: transports, the message envelope, the handshake and capabilities, every dock message, stems and rights, routines (hooks, context, limits, packaging and two complete examples), and the cartridge messages and manifest.
Good places to start:
- Building a speaker or an amp: profiles, pinout and the Reference Bollard.
- Building your first light puck: hobbyist builds.
- Writing dock software: the handshake and the example dock.
- Writing a routine: hooks and the example routines.
- Building a cartridge: the Bolltridge device class and the cartridge manifest.
- Writing a renderer or a tool for a PWHAMSS device: the frame and event contract and the Glass Snipler's modes and sniplets.
Status and versioning#
Everything here is a speculative draft. No Pop Boll, dock or cartridge has been built to these documents, and there is no shipping date. Each specification ends with an "Open items" section that lists what has not yet been validated on hardware.
| Document | Version | Wire identifiers |
|---|---|---|
| Bollard Physical Specification | 1.0-draft | header magic BLD1, JSON "bollard": "1.0" |
| bollardeck API, Parts A and C | 0.1-draft | wire protocol bollardeck/1, envelope "v": 1 |
| bollardeck API, Part B (routines) | 0.1-draft | routine API api: 1 |
| Bolltridge extension | 0.1 | bolltridge: 0.1 in the cartridge manifest |
| Glass Snipler: Device Specification | 0.0.1-draft | sniplet ids sn_ + 12 hex, frame "v": 1 |
| PWHAMSS | 0.0.1-draft | frame and event envelope "v": 1 |
- Bollard minor versions only add registers, classes, profiles or JSON fields. Any mechanical change, or any change to an assigned pin, is a new major version with a new header magic.
- bollardeck additions within a major version are optional fields, new message types, new error codes and new capabilities. Removing a field or changing its meaning is a new major version, negotiated in the
hellohandshake. - The two move independently. A Bollard v1.0 dock speaks
bollardeck/1. - Expect breaking changes before the 1.0 final releases. Each page carries its own change log.
Licence (proposed)#
The licences below are proposed and not yet final:
- Hardware designs (the Reference Bollard and Lux Puck designs, the reference pad strip, the gauges, the mechanical drawings): CERN-OHL-P v2, a permissive licence, so anyone can build and sell closed commercial docks.
- Firmware and code (the puck microcontroller reference, the bollardeck client libraries, the example dock and the example routines): Apache-2.0, which includes an explicit patent grant.
- The specification text: CC BY 4.0.
These licences cover the documents, designs and code, not the project's names and logos. You may describe a product as "built to the Bollard Physical Specification v1.0, Full profile" (or whichever profile applies).
Get in touch#
Use the contact form below. We would especially like to hear from:
- dock, speaker and accessory makers interested in partnership or OEM work;
- developers who want a dev kit when one exists;
- anyone who finds a mistake, an ambiguity or a missing number in these drafts.
Tell us what you want to build and which profile you have in mind. Nothing you send commits either of us to anything.
FAQ#
Can I build and sell a dock?#
Yes. That is the point of an open specification. Build any shape, on any profile, and sell it under your own name at any price. The Reference Bollard speaker is an open reference design that anyone may build and sell as well. Because these are drafts, please do not cut production tooling until the 1.0 final versions are published.
Do I need permission?#
No. There is no certification, no licence fee and no approval step for hardware. Conformance is self-declared: if you say your product is "Bollard v1.0, Full profile", you are stating that it passes the checklist for that profile. You are responsible for your product's safety and regulatory compliance. A future storefront may list docks, and listing would ask for a short self-declaration, but it will not be required to build or sell anything. Cartridge images are different: a Boll runs only signed images, unless its owner has turned on hacker mode.
When will Bolls ship?#
There is no date. No Pop Boll hardware has shipped, and this specification is published ahead of the hardware so that people can comment on it and start designing.
Can I get a dev kit?#
Not yet. A reference cartridge, the Bolltridge Dev Puck, is specified but not built, and the reference gauges for the Boll's foot and a dock's top face will be published with v1.0 final. If you would like a dev kit when one exists, say so through the contact form. In the meantime, the hobbyist builds in the Bollard specification show how to make a first light puck from perfboard and printed parts.
Can routines run on the website?#
No. Routines run only on your own Pop Boll. The website never runs user routines, and its song factory loads none. Routines work only with the corpora already on your Boll, and no API creates corpora.
Does my accessory have to touch the Boll?#
No. Any accessory can speak bollardeck over Bluetooth Low Energy with no physical connection at all. A physical Bollard connection adds charging, analog audio, USB and hardware sync.