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Stephen Holdaway stecman

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stecman / grid.less
Last active Mar 5, 2021
Mixin based grid for LESS with scoped grid settings
View grid.less
// Based on
// Defaults
@columns: 12;
@gutter-width: 25px;
@total-width: 100%;
// Uncomment these two lines and the star-hack width/margin lines below to enable sub-pixel
stecman / AutoCrop.lua
Last active Feb 25, 2021
Lightroom plugin to calculate image crops using OpenCV
View AutoCrop.lua
-- LR imports
local LrApplication = import("LrApplication")
local LrApplicationView = import("LrApplicationView")
local LrBinding = import("LrBinding")
local LrDevelopController = import("LrDevelopController")
local LrDialogs = import("LrDialogs")
local LrExportSession = import("LrExportSession")
local LrFileUtils = import("LrFileUtils")
local LrFunctionContext = import("LrFunctionContext")
local LrLogger = import("LrLogger")
stecman / SConscript
Last active Feb 24, 2021
STM8 WS2812 hacked together demo
View SConscript
import os
# Device definition for the stm8s.h header
# This enables available features of the device library.
# Programmer argument for stm8flash (stlink or stlinkv2)
STM8_PROGRAMMER = "stlinkv2"
# Target device argument for stm8flash
stecman /
Last active Feb 13, 2021
Dumping all bytecode from a packaged Python application

This is a technique for extracting all imported modules from a packaged Python application as .pyc files, then decompiling them. The target program needs to be run from scratch, but no debugging symbols are necessary (assuming an unmodified build of Python is being used).

This was originally performed on 64-bit Linux with a Python 3.6 target. The Python scripts have since been updated to handle pyc files for Python 2.7 - 3.9.


In Python we can leverage the fact that any module import involving a .py* file will eventually arrive as ready-to-execute Python code object at this function:

PyObject* PyEval_EvalCode(PyObject *co, PyObject *globals, PyObject *locals);

This is a collection of code snippets for various features on the STM8S family microcontrollers (specifically the STM8S003F3). These are written against the STM8S/A SPL headers and compiled using SDCC.

Some of this controller's functions aren't particularly intuitive to program, so I'm dumping samples for future reference here. These are based on the STM8S documentation:

Run at 16MHz

stecman /
Last active Jan 11, 2021
Brother P-Touch PT-P300BT bluetooth driver python

Controlling the Brother P-Touch Cube label maker from a computer

The Brother PTP300BT label maker is intended to be controlled using the official Brother P-Touch Design & Print iOS/Android app. The app has arbitrary limits on what you can print (1 text object and up to 3 preset icons), so I thought it would be a fun challenge to reverse engineer the protocol to print whatever I wanted.

Python code at the bottom if you want to skip the fine details.


Intitially I had a quick peek at the Android APK to see if there was any useful information inside. The code that handles the communication with the printer in Print&Design turned out to be a native library, but the app clearly prepares a bitmap image and passes it to this native library for printing. Bitmaps are definitely something we can work with.

stecman /
Last active Dec 22, 2020
ffmpeg streaming examples

FFmpeg streaming

These are some ffmpeg command lines used when developing VHS dubbing controller.

HLS Stream (on Linux)


# Stream a PAL 50i capture, cropped and de-interlaced using ffmpeg
stecman / monday-for-week.php
Last active Dec 7, 2020
Reliable PHP function to return Monday for week (pre-PHP 7.1)
View monday-for-week.php
* Find the starting Monday for the given week (or for the current week if no date is passed)
* This is required as strtotime considers Sunday the first day of a week,
* making strtotime('Monday this week') on a Sunday return the adjacent Monday
* instead of the previous one.
* @param string|\DateTime|null $date
stecman /
Last active Nov 23, 2020
bash-completion extract for dealing with colons

Extract from bash-completion for working with stecman/symfony-console-completion

This is an example extract of the minimum amount of the bash-completion project required to use these two functions:

  • __ltrim_colon_completions
  • _get_comp_words_by_ref

The functions here are copied verbatim from the bash_completion source. I recommend not using this extract unless there are no other alternatives. Instead, prefer installing the bash-completion package from your package manager, or install bash-completion from source.

stecman /
Last active Nov 2, 2020
DS18B20 1-Wire implementation for Atmel AVR

AVR C 1-Wire + DS18B20 temperature sensor

This implements Maxim's One Wire / 1-Wire protocol for AVR microcontrollers from the DS18B20 datasheet and Maxim's other application notes.


Single DS18B20 device on bus

With just one DS18B20 on the 1-Wire bus, you can ignore slave addresses: