Jed Parsons jedp

Controlling addressable LEDs with STM32 SPI + DMA

Overview

RGB5050 LEDs are programmed by sending a stream of 24-bit GRB packets, MSB first.

The logical 1s and 0s in the packets are encoded on a single line which is sent high or low with these timings:

0 -> 0.3µs high ± 0.15µs, 0.9us low ± 0.15µs

Fixing Ludicrous Java Localhost DNS Lookup on Mac

I recently started using the excellent adm wrapper for the android debug bridge.

I quickly noticed that my app was hanging on startup on an aarch_64 (Apple M1) machine.

Fortunately, vert.x, a dependency of adm, gave the following warning:

[vertx-blocked-thread-checker] WARN io.vertx.core.impl.BlockedThreadChecker - Thread Thread[vert.x-eventloop-thread-0,5,main] has been blocked for 4985 ms, time limit is 2000 ms

	# /etc/raspotify/conf -- Arguments/configuration for librespot

	# A non-exhaustive list of librespot options and flags.

	# Please see https://github.com/dtcooper/raspotify/wiki &
	# https://github.com/librespot-org/librespot/wiki/Options
	# for configuration details and a full list of options and flags.

	# You can also find a full list with `librespot -h`.

	#define ETAPE A0

	// Set crucial level as appropriate for your needs.
	// For me, 687 indicates three inches of water.
	#define CRUCIAL_LEVEL 687
	#define LED_RED 13
	#define LED_GREEN 12

	float resistance;

	#define ETAPE A0

	// Set crucial level as appropriate for your needs.
	// For me, 687 indicates three inches of water.
	#define CRUCIAL_LEVEL 687
	#define LED_RED 13

	float resistance;

	void setup(void) {

	#define ETAPE A0

	float resistance;

	void setup(void) {
	Serial.begin(9600);
	}

	void loop(void) {
	resistance = analogRead(ETAPE);

	if version < 704
	" if we are somehow running a version lower than 7.4,
	" something's wrong, so just stop processing this file.
	finish
	endif

	" auto reload vimrc after edit
	autocmd! bufwritepost .vimrc source %

	" vi? is it even possible to run original vi anymore?

	# Answer to a ruby koan:
	# http://koans.heroku.com/en/about_proxy_object_project

	# Project: Create a Proxy Class
	#
	# In this assignment, create a proxy class (one is started for you
	# below). You should be able to initialize the proxy object with any
	# object. Any messages sent to the proxy object should be forwarded
	# to the target object. As each message is sent, the proxy should
	# record the name of the method send.

	# http://koans.heroku.com/en/about_triangle_project_2
	#
	# XXX why does the second TriangleError.new cause a syntax error
	# in the heroku web app, but not in my irb repl!?

	class TriangleError < Exception
	end

	def triangle(a, b, c)
	sides = [a, b, c]

	. $topsrcdir/browser/config/mozconfig

	# Define where build files should go. This places them in the directory
	# "obj-ff-dbg" under the current source directory
	mk_add_options MOZ_OBJDIR=../build_mc

	# -s makes builds quieter by default
	# -j4 allows 4 tasks to run in parallel. Set the number to be the amount of
	# cores in your machine. 4 is a good number.
	mk_add_options MOZ_MAKE_FLAGS="-s -j6"