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Display Server Notifications Using a blink(1)

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The blink(1) is an open source USB notification light that can be controlled from the command line.

blink(1) set to full green

I couldn’t find a pre-built package for it in FreeBSD but it was easy to compile directly from source. To do so, install a few dependencies and then clone the repository.

$ su
Password:

# pkg install -y gcc git gmake libiconv
[...]

# cd /tmp && git clone https://github.com/todbot/blink1-tool
[...]

Compile the blink1-tool and install it on the system.

# cd blink1-tool && gmake && install blink1-tool /usr/local/bin
[...]

# which blink1-tool
/usr/local/bin/blink1-tool

Insert the device into a USB port and make sure the system identifies it.

# dmesg
[...]
ugen0.3: <ThingM blink(1) mk3> at usbus0
uhid0 on uhub1
uhid0: <ThingM blink(1) mk3, class 0/0, rev 2.00/1.01, addr 5> on usbus0

# blink1-tool --list
blink(1) list:
id:0 - serialnum:3d5ee772 (mk3) fw version:303

The documentation explains the program’s basic usage.

Specify --green to set the LED color to solid green.

# blink1-tool --green

Specify --red --blink 10 to set the LED color to red and flash it 10 times.

# blink1-tool --red --blink 10

Reset the device using --off.

# blink1-tool --off

Use --playpattern <patternstr> to create more complicated patterns.

The<patternstr> parameter consists of a list of values separated by commas. The first value in the list is a repeat count indicating how many times the entire sequence should be repeated or 0 to indicate that the sequence should repeat forever. Following the repeat count is a list of triples, each of which contains a hexidecimal RGB to specify color, a float to specify the event length in seconds and an integer between 0 and 2 to indicate which LEDs to use.

For example, a sample pattern can be built up like this:

  • ' begin the pattern string
  • 0, repeat forever
  • #ff0000,1.0,0, display red for 1 second on both LEDs
  • #000000,1.0,0, display nothing for 1 second on both LEDs
  • #00ff00,2.0,1, display green for 2 seconds on the bottom LED
  • #000000,1.0,0, display nothing for 1 second on both LEDs
  • #0000ff,3.0,2, display blue for 3 seconds on the top LED
  • #000000,1.0,0 display nothing for 1 second on both LEDs
  • ' end the pattern string

Set the transition time between states to 0ms using -m 0 and the entire command looks like this:

# blink1-tool --playpattern '0,#ff0000,1.0,0,#000000,1.0,0,#00ff00,2.0,1,#000000,1.0,0,#0000ff,3.0,2,#000000,1.0,0' -m 0

Use --help to see more detailed usage examples.

# blink1-tool --help