compass

This application reads bearings and plots them on a compass

In its current implementation, it reads 23 (or 25 if padding is used) character lines from STDIN and plots bearing circles on a compass.

Building

go build

Alternatively, you can set the OS and ARCH when compiling the code.

• Build for Raspberry PI (ARM) Running 32 bit Linux

  GOOS=linux GOARCH=arm go build

• Build for RaspBerry PI (ARM) running 64 bit Linux

  GOOS=linux GOARCH=arm64 go build

Usage

% ./compass --help
Usage of ./compass:
  -accessible
    	Enable accessible color mode
  -bearings int
    	Max bearings to cache (default 20)
  -colors string
    	5 colors to use for displaying magnitude, low to high (default "#2c7bb6,#abd9e9,#ffffbf,#fdae61,#d7191c")
  -darkmode
    	Enable dark mode
  -expire int
    	Bearing expire interval in milliseconds (default 2000)
  -paddedTimestamp
    	Pad timestamps to 15 digits
  -refresh int
    	Refresh interval in milliseconds (default 200)
  -rows int
    	Max table rows to display (default 5)

Generating fake input data

13 digit millisecond unix timestamps:

for i in $(seq -f "%03g" 0 359) ; do echo -n "C$i" ; echo -n "0000000" ; printf "%010d" "$(($(date +%s)))" ; echo "000" ; sleep 0.5 ; done >> bearings

15 digit millisecond unix timestamps:

for i in $(seq -f "%03g" 0 359) ; do echo -n "C$i" ; echo -n "0000000" ; printf "%012d" "$(($(date +%s)))" ; echo "000" ; sleep 0.5 ; done >> bearings

Example run

tail -F bearings | ./compass -bearings=30 -refresh=100 -expire=1500

Gradient versus accessibility colors

By default, the bearings are displayed in gradients of color (based on the magnitude):

• Dark Blue (min)
• Light Blue
• White
• Yellow
• Orange
• Red
• Brown (max)

For accessbility reasons, you can run the server with -accessible and it will only display 5 colors, changing at every magnitude increase by 200:

• #2c7bb6
• #abd9e9
• #ffffbf
• #fdae61
• #d7191c

You can override the default colors from command line, appending -colors with the value being five comma sepparated colors expressed as hex values with leading hashtag (Eg: -colors="#2c7bb6,#abd9e9,#ffffbf,#fdae61,#d7191c")

Sample UI

Fake data input with 70.0° and ~770 magnitude.

Dark Mode

Complete list of OS and ARCH

With GO version 1.21.0, the following OS and ARCH combinations are allowed as seen in go tool dist list:

OS \ ARCH	386	amd64	arm	arm64	loong64	mips	mips64	mips64le	mipsle	ppc64	ppc64le	riscv64	s390x	WASM
aix										X
android	X	X	X	X
darwin		X		X
dragonfly		X
freebsd	X	X	X	X								X
illumos		X
ios		X		X
js														X
linux	X	X	X	X	X	X	X	X	X	X	X	X	X
netbsd	X	X	X	X
openbsd	X	X	X	X
plan9	X	X	X
solaris		X
wasip1														X
windows	X	X	X	X