61 lines
2.7 KiB
Markdown
61 lines
2.7 KiB
Markdown
|
# GoTelem: Golang-based telemetry tools
|
||
|
|
|
||
|
|
`GoTelem` is a toolkit and library to make working with solar car telemetry
|
||
|
|
data fast, reliable, and insightful.
|
||
|
|
|
||
|
|
Features:
|
||
|
|
|
||
|
|
- SocketCAN interface for connecting to physical hardware.
|
||
|
|
- TCP streaming system based around MessagePack-RPC for LAN control/inspection.
|
||
|
|
- XBee integration and control for long-range communication.
|
||
|
|
- HTTP API for easy external tool integration.
|
||
|
|
|
||
|
|
|
||
|
|
`GoTelem` provides a flexible system for ingesting, storing, analyzing, and distributing
|
||
|
|
telemetry information.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
## Rationale
|
||
|
|
|
||
|
|
There are probably two questions:
|
||
|
|
|
||
|
|
1. Why a telemetry library that runs on an OS?
|
||
|
|
2. Why is it written in Go?
|
||
|
|
|
||
|
|
To answer the first question, the needs of the telemetry board are ill-suited for a microcontroller
|
||
|
|
since it requires doing multiple non-trivial tasks in parallel. The on-car system must ingest
|
||
|
|
all can packets, write them to disk, and then transmit them over XBee if they match a filter.
|
||
|
|
Doing fast disk I/O is difficult.
|
||
|
|
|
||
|
|
There are also significant advantages to moving to using a Linux system for telemetry. We gain
|
||
|
|
Wifi/Bluetooth/network support easily, we can integrate USB devices like a USB GPS reciever,
|
||
|
|
and we can share common tooling between the car code and the receiver code.
|
||
|
|
|
||
|
|
I chose to write this in Go because Go has good concurrency support, good cross-compilation,
|
||
|
|
and relatively good performance.
|
||
|
|
|
||
|
|
C/C++ was eliminated due to being too close to the metal and having bad tooling/cross compilation.
|
||
|
|
|
||
|
|
Python was eliminated due to having poor concurrency support and difficult packaging/distribution.
|
||
|
|
It also lacks a good http/networking story, instead relying on WSGI/ASGI packages which
|
||
|
|
make Windows not viable. Futhermore, being dynamically typed leads to issues in asserting
|
||
|
|
robustness of the code.
|
||
|
|
|
||
|
|
Rust was elminiated due to being too different from more common programming languages. Likewise
|
||
|
|
for F#, C#, D, Zig, Nim, Julia, Racket, Elixr, and Common Lisp. Yes, I did seriouisly consider each
|
||
|
|
of these.
|
||
|
|
|
||
|
|
Go has some quirks and -isms, like lacking "true" Object-Orientation, but the language is designed
|
||
|
|
around being normal to look at, easy to write, and straightforward to understand.
|
||
|
|
|
||
|
|
Go has really good cross compilation support built in to the `go` binary. However, since this
|
||
|
|
package uses some C libraries (SQLite), certain functionality will be missing if you don't
|
||
|
|
have a cross-compiler set up. There's a way to make things easier on Linux
|
||
|
|
[using `zig cc`](https://zig.news/kristoff/building-sqlite-with-cgo-for-every-os-4cic)
|
||
|
|
but this is not usually important since the user can pretty easily compile it on their
|
||
|
|
own system, and it's a single executable to share to others with the same OS/architecture.
|
||
|
|
|
||
|
|
## Building
|
||
|
|
|
||
|
|
There are build tags to enable/disable certain features, like the graphical GUI.
|