# physical

<div align="right"><img src="https://4075073488-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FV9R366GtJi7slXbSunO8%2Fuploads%2F68d2JFkXt9G84vrNq6gx%2Fhelix.jpg?alt=media&#x26;token=61681c14-43a5-43c8-a754-97855158f2d4" alt="an early sketch of our first exoskeleton (a band of linked modules, which ↔ collapses into a helix / hand grasped sceptre when coiled in one direction and ↔ forms a loop / neck worn choker when flexed in the other direction)
image: Compossible Umwelten 2021"> <figure><img src="https://4075073488-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FV9R366GtJi7slXbSunO8%2Fuploads%2FIAVVDu3LiIFyqdAT3Ej8%2Fproject%20bobtai%202022%2008%2025.png?alt=media&#x26;token=fd6a4510-e26d-4a90-af95-94aa200bd632" alt=""><figcaption><p>our initial 3 products will be an interface, a platform and a module (which will be built on top of three different boards) <br>image: Compossible Umwelten 2022</p></figcaption></figure></div>

Our initial three products are:

* **Neck | Hand Interface.** A mass market consumer product.
* **Wearable platform.** Niche market, for hardware developers working on wired arrays with wireless connectivity.
* **Neuro-tactile module.** Niche market, for laboratories researching haptics or bio-potentials.

Some details about these three follow.&#x20;

## exoskeletons

We incorporate our neuro-tactile module (ref. subsystems below) into our wearable platform (ref. subsystems below) to produce several different macro forms. Community members may make their own forms. Initially we'll work on a helical form and at a later stage we'll release some others.&#x20;

### neck | hand interface

A band which forms either either a neck worn choker (wearable) or a hand held sceptre (graspable), as in the image at the top of this page. Each segment in the array has a module in it. This will likely be our first shelf ready device.

### later forms

#### ribbon

Wrappable. Two variable length module arrays. Similar to the helix but with more flexible macro movement. May be installed on a handle of some kind. e.g. on a walking stick, an umbrella, an oar, a racquet, bow or the like.&#x20;

#### pair

Strappable. Two modules placed \~5 cm apart (like dumbbells). May be strapped to various locations. We expect this to be a quick way for graduate students to get their experiments up and running.&#x20;

#### grid

A tabletop pad on which one may place one's hand.

## subsystems

We're developing two subsystems which we integrate to form various exoskeletons. These subsystems may be of interest to hobbyists, researchers, developers and hardware tinkerers

### wearable platform (wireless array)

Many of the devices we wear / carry around with us contain a hardware unit confined to a single space. Our wearable platform has a central 'crest board' (ref. below) with a battery and wireless connectivity and is physically wired to long arrays of 'edge boards' (ref. below). Several different devices may be built on top of this.&#x20;

#### edge board

Built around an RP2040 (<https://www.raspberrypi.com/products/rp2040/> ) connected via a buck. Uses I2C as an address and control bus, disconnect-able SPI and UART buses for data and a disconnect-able USB bus to update the firmware of each board separately. They may be daisy chained to form a common bus with relatively few wires across boards.&#x20;

#### crest board

A HAT / base which mates with a Raspberry Pi Compute Module 4 ( <https://www.raspberrypi.com/products/compute-module-4/> ); has a battery management system, peripherals and is intended to work with two arrays of Edge Boards.

### neuro-tactile module

It incorporates an eXg-haptic board (ref. below) and edge board (ref. above) into a single unit. May be of interest to laboratories conducting haptic and bio-potential experiments.&#x20;

#### eXg-haptic board

A (1) bioelectric sensor (capacitive, dry, single electrode ExG) (2) a piezo unit functioning as a vibro-tactile (haptic) stimulator / actuator and vibration sensor and (3) an external temperature sensor, with an (4) optional IMU, an (5) optional LRA and an (6) optional LED.

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