thomasbhatia

# Defaults / Configuration options for homebridge
# The following settings tells homebridge where to find the config.json file and where to persist the data (i.e. pairing and others)
HOMEBRIDGE_OPTS=-U /var/lib/homebridge

# If you uncomment the following line, homebridge will log more 
# You can display this via systemd's journalctl: journalctl -f -u homebridge
# DEBUG=*

thomasbhatia

[Unit]
Description=Mosquitto MQTT Broker daemon
ConditionPathExists=/etc/mosquitto/mosquitto.conf
After=network.target
Requires=network.target

[Service] 
Type=forking 
RemainAfterExit=no 
StartLimitInterval=0 

thomasbhatia

-module(udptest).

-export([start_sender/2, start_reader/2]).


start_sender(Addr, Port) ->
  Options0 = [{broadcast, true}, {reuseaddr, true}, {active, once}, {multicast_loop, true},
             {multicast_ttl, 4}, {high_msgq_watermark, 262144}, {low_msgq_watermark, 65536}, {sndbuf, 262144}],
  % {multicast_if, {127,0,0,1}}],
  Options = Options0,

thomasbhatia

HomeKit Service and Characteristic UUIDs

Thanks to HAP-NodeJS

Service	UUID
Accessory Information	0000003E-0000-1000-8000-0026BB765291
Air Quality Sensor	0000008D-0000-1000-8000-0026BB765291
Battery Service	00000096-0000-1000-8000-0026BB765291
Bridging State	00000062-0000-1000-8000-0026BB765291

thomasbhatia

   Wordlist ver 0.732 - EXPECT INCOMPATIBLE CHANGES;
  acrobat  africa   alaska   albert   albino   album    
  alcohol  alex     alpha    amadeus  amanda   amazon   
  america  analog   animal   antenna  antonio  apollo   
  april    aroma    artist   aspirin  athlete  atlas    
  banana   bandit   banjo    bikini   bingo    bonus    
  camera   canada   carbon   casino   catalog  cinema   
  citizen  cobra    comet    compact  complex  context  
  credit   critic   crystal  culture  david    delta    
  dialog   diploma  doctor   domino   dragon   drama    

thomasbhatia

For development it may be useful to be able to replay TCP traffic (e.g. HTTP). The dump can be created using WireShark or tcpdump:
$ tcpdump -s 0 port http -i en0 -w dump.pcap

To generate data files that can be replayed through netcat we use tcptrace:
$ tcptrace -e input.pcapng

Finally replay the HTTP traffic using netcat to host 192.168.1.1 port 80
$ cat a2b_contents.dat | nc -v 192.168.1.1 80

If you need to replay the raw network traffic, we need to do some massaging using tcpprep and tcprewrite before using tcpreplay to replay the raw packages. Note that due to limitation of tcprewrite this will not replay any traffic to the network: http://tcpreplay.synfin.net/wiki/FAQ#Doestcpreplaysupportsendingtraffictoaserver.

thomasbhatia

Erlang and Named Pipes

The intention of this post is to provide a solution (with examples) to a somewhat uncommon issue in Erlang. I hate searching for answers to the same problems over and over, and I had a hard time finding answers to this particular problem, so I wrote it all down once I figured it out. If one day you decide to read and write data through fifo's (named pipes) and then decide you want to read or write the other end of the pipe from Erlang, this post is for you.

The Problem

I wanted to read and write to a fifo from a C/C++ app and have an Erlang app communicate over the other end of that fifo. Put simply, Erlang doesn't really support what I was trying to do. You cannot just file:open/2 a fifo, or any special device for that matter, in Erlang and expect it to work. This is documented in Erlang's FAQ.

The Solution! ... ???

thomasbhatia

Studying for a Tech Interview Sucks, so Here's a Cheat Sheet to Help

This list is meant to be a both a quick guide and reference for further research into these topics. It's basically a summary of that comp sci course you never took or forgot about, so there's no way it can cover everything in depth. It also will be available as a gist on Github for everyone to edit and add to.

Data Structure Basics

###Array ####Definition:

• Stores data elements based on an sequential, most commonly 0 based, index.
• Based on tuples from set theory.

thomasbhatia

ZeroMQ vs Redis

This document is research for the selection of a communication platform for robot-net.

Goal

The purpose of this component is to enable rapid, reliable, and elegant communication between the various nodes of the network, including controllers, sensors, and actuators (robot drivers). It will act as the core of robot-net to create a standardized infrastructure for robot control.

Requirements:

thomasbhatia

obj-m += tcp_svr_sample.o
 
all:
	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
 
clean:
	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clea