This library is in the design phase.
Bridge is a protocol designed to allow a system of different devices, to communicate with each other and issue commands through lightweight and robust remote procedural calls. It allows inter-network communication through the concept of "bridges". Both nodes and bridges can be highly resource constrained devices (such as microcontrollers). Intended supported networks include tcp/ip, UART, CAN and ZigBee.
The Bridge Protocol has the following requirements:
- lightweight: both nodes and bridges can be run completely on the stack of microcontrollers with as little as 4k RAM
- simple: The entire protocol is governed by a small set of easy to implement rules that are defined by the rust typsestem. There are only two kinds of devices: nodes and bridges. Bridges are just nodes which also store a register of existing nodes and pass data along to its destination.
- network agnostic: can be run on any network that is masterless and has the ability to broadcast (tcp/ip, UART, CAN, etc).
- bridged: enables seamless communication between different networks via what are known as "bridge nodes". Through bridges, a node on ethernet can communicate with a node on CAN (or any other protocol) through an arbitrary number of bridges.
- flexibly robust: supports any range on the spectrum of robustness vs
guaranteed performance. When configured, data can always be re-requested
and the user is guaranteed to never accidentally get duplicate data or call
the same RPC twice.
- functions can be configured to never drop their return values (until the initiator clears them) in order guarantee crticial data
- functions can drop their return values immediately for idempotent operations and guaranteed performance.
- functions can have user-defined events of when they drop values (i.e. timeout, buffer fullness, etc)
- functions can store an index and only run when the index matches the
cx_idof the RPC, guaranteing that functions cannot be run twice accidentally.
The library will be split up into several libraries/crates:
- bridge-constants: provides generated constants for multiple languages
- bridge-logic-rs: contains core rust data types and logic handlers to implement the protocol.
- bridge-std-rs: contains higher logic implemented using the std library (including heap memory allocation and threading).
- bridge-uc-rs: contains higher logic implemented for microcontrollers (no heap memory allocation or threading)
The reference and primary implementation for all device types shall be in rust.