Florian Dejonckheere floriandejonckheere

PicoRuby Workshop 2025 - Setup & LED Control

Before starting, please check the following resources:

Terminal emulator (Many of you have already read): https://picoruby.github.io/terminal-emulator
Setup R2P2: https://picoruby.github.io/setup
- In this workshop, we use R2P2-PICORUBY-PICO2_W-*.uf2 (PICO2_W is the point)
Breadboard basics: https://picoruby.github.io/breadboard-basics
Troubleshooting: https://picoruby.github.io/troubleshooting

ZSH CheatSheet

This is a cheat sheet for how to perform various actions to ZSH, which can be tricky to find on the web as the syntax is not intuitive and it is generally not very well-documented.

Strings

Description	Syntax
Get the length of a string	`${#VARNAME}`
Get a single character	`${VARNAME[index]}`

Scenario

I want to use Rspec to build feature specs that test SR pages, just like normal web pages.

Therefore, I expect Capybara + Rspec to be able to do things like:

visit login_path
fill_in 'Email', with: user.email
fill_in 'Password', with: user.password + 'BAD'
expect(page).to have_content('That email or password is not correct')

How to use

In iTerm2, in the menu bar go to Scripts > Manage > New Python Script

Select Basic. Select Long-Running Daemon

Give the script a decent name (I chose auto_dark_mode.py)

Save and open the script in your editor of choice.

Create a Wi-Fi hotspot on Linux using `nmcli`

Original post : https://unix.stackexchange.com/a/310699

nmcli con add type wifi ifname wlan0 con-name Hostspot autoconnect yes ssid Hostspot
nmcli con modify Hostspot 802-11-wireless.mode ap 802-11-wireless.band bg ipv4.method shared
nmcli con modify Hostspot wifi-sec.key-mgmt wpa-psk
nmcli con modify Hostspot wifi-sec.psk "veryveryhardpassword1234"

	##########################################
	######## NickelMenu configuration ########
	##########################################

	#
	## Main Menu
	#
	menu_item : main : Pocket : nickel_open: library : pocket
	menu_item : main : Browser (full window) : nickel_browser :
	menu_item : main : Browser (popup) : nickel_browser : modal

	#!/bin/sh
	# Configure homebrew permissions to allow multiple users on MAC OSX.
	# Any user from the admin group will be able to manage the homebrew and cask installation on the machine.

	# allow admins to manage homebrew's local install directory
	chgrp -R admin /usr/local
	chmod -R g+w /usr/local

	# allow admins to homebrew's local cache of formulae and source files
	chgrp -R admin /Library/Caches/Homebrew

	1) Install iTerm2, it's awesome.

	2) locate your rubymine commandline integration thingy, it's usually `/usr/local/bin/mine`

	3) Open iTerm2 preferences. Go to Profiles -> Default -> Advanced.

	4) Select "Run command..." under Semantic History

	5) Enter "/usr/local/bin/mine --line \2 \1" as the command

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD