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@stecman
stecman / _readme.md
Last active Jan 18, 2020
Brother P-Touch PT-P300BT bluetooth driver python
View _readme.md

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.

Process

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
stecman / config.txt
Last active Jan 17, 2020
Raspberry Pi 2 B+ 1440x2560 resolution config
View config.txt
# Enable 1440x2560 resolution (mobile phone screen that expects this orientation)
hdmi_group=2
hdmi_mode=87
hdmi_pixel_freq_limit=400000000
hvs_priority=0x32ff
max_framebuffer_width=1440
max_framebuffer_height=2560
framebuffer_width=1440
framebuffer_height=2560
View How to Git.md

Note: this is an extract from Heyday's internal docs, written by me. Published as a Gist to share the love.

Authoring commits

We like sensible commit messages. There're a lot of good articles about writing great, useful commit messages, but here's the gist of what we like:

  • The single most important thing is: commit messages should explain why you are making the change.
  • Think, "what would future me want to know about this change?"
  • Avoid committing multiple sets of ideas/changes in the same commit: split them up.
  • Don't assume the reader understands what the original problem was.
@stecman
stecman / SConscript
Last active Dec 30, 2019
STM8 WS2812 hacked together demo
View SConscript
import os
# Device definition for the stm8s.h header
# This enables available features of the device library.
STM8_DEVICE_DEFINE = "STM8S003"
# Programmer argument for stm8flash (stlink or stlinkv2)
STM8_PROGRAMMER = "stlinkv2"
# Target device argument for stm8flash
@stecman
stecman / AutoCrop.lua
Last active Dec 8, 2019
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
stecman / _NMEA GPS datetime for AVR.md
Last active Oct 16, 2019
NMEA GPRMC sentence parsing for low memory microcontrollers: read GPS date and time from UART
View _NMEA GPS datetime for AVR.md

Date/time from GPS without storing NMEA string

This is a first pass at reading the date and time from a serial GPS device on a tiny microcontroller. The target device is an ATTiny13A with only 64 bytes of RAM, which isn't enough to store the full 79 characters of a NMEA sentence, so something like minmea wouldn't work (their API passes around full sentence strings).

When compiled with avr-gcc -Os, this is around 500 bytes of program space. The size can be reduced by 100 bytes if the handling of checksums is removed.

@stecman
stecman / README.md
Last active Sep 28, 2019
Pushover notification CLI script
View README.md

Send Pushover notifications from the command line

Notify is a utility for sending push notifications via Pushover from the command line. It can be run manually, but is most useful for sending notifications from shell scripts, cron jobs, and long running tasks.

Pushover screenshot

Installation

To install, copy the contents of notify.php to somewhere on your computer, and make it executable:

@stecman
stecman / silverstripe-remove-empty-tabs.php
Last active Aug 13, 2019
Remove empty tabs in the SilverStripe CMS
View silverstripe-remove-empty-tabs.php
/**
* Recurse through tabs and remove any with no child fields
*
* The way SilverStripe's field scaffolding works can leave empty tabs around after
* fields are moved or removed by the slices module.
*
* @param FieldList $fields
* @return FieldList
*/
protected function removeEmptyTabs(FieldList $fields)
@stecman
stecman / index.htm
Last active Aug 9, 2019
CSS3 playing cards with flexbox
View index.htm
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Cards</title>
<link href="http://fonts.googleapis.com/css?family=Roboto" rel="stylesheet" type="text/css">
<link rel="stylesheet" type="text/css" href="style.css">
</head>
@stecman
stecman / dump-pyc-with-gdb.md
Created Jun 30, 2019
Dumping all bytecode from a packaged Python application
View dump-pyc-with-gdb.md

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 performed on 64-bit Linux with a Python 3.6 target.

Theory

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);
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