Ludwig Behm lbehm

Prometheus Water Meter

This is a fairly involved process as it seems that no one currently makes a pre-made product that measures water usage from a household meter.

It took quite a while to set up due to WiFi issues and the flow rate code still needs some work as the output is semi-random at the moment.

If you get stuck anywhere I'm happy to answer questions provided this doesn't go viral 😂

Components:

DFRobot Beetle ESP32 microcontroller (https://www.littlebird.com.au/products/beetle-esp32-microcontroller)
Water meter pulse probe for the specific meter model (https://www.aquatrip.com.au/accessories is one of the only places I've found that sells them)

Using Uni2Me

It's free but discontinued.

Using UTFCast

Proprietary software
Allows conversion from ANSI to UTF-8 with or without BOM

Using Notepad++

Cryptographic Best Practices

Putting cryptographic primitives together is a lot like putting a jigsaw puzzle together, where all the pieces are cut exactly the same way, but there is only one correct solution. Thankfully, there are some projects out there that are working hard to make sure developers are getting it right.

The following advice comes from years of research from leading security researchers, developers, and cryptographers. This Gist was [forked from Thomas Ptacek's Gist][1] to be more readable. Additions have been added from

	# If you, like me, have all of your various source-code-like projects in ~/src/
	# this is how to give yourself per-project shell history.
	#
	# I wish I'd done this years ago.
	#
	# First, in your .bashrc file, you redefine the cd, pushd and popd builtins to be "do the builtin bit,
	# then do one other thing (set_src_history.sh, below) like so:


	cd () {

	#include <stdio.h>

	#define SQ(x) (x)*(x)

	#define M0(x,y) SQ(x)+SQ(y)<4?0:0xe0
	#define M1(x,y,x0,y0) (SQ(x)+SQ(y)<4)?M0(SQ(x)-SQ(y)+(x0),2(x)(y)+(y0)):0xc0
	#define M2(x,y,x0,y0) (SQ(x)+SQ(y)<4)?M1(SQ(x)-SQ(y)+(x0),2(x)(y)+(y0),x0,y0):0xa0
	#define M3(x,y,x0,y0) (SQ(x)+SQ(y)<4)?M2(SQ(x)-SQ(y)+(x0),2(x)(y)+(y0),x0,y0):0x80
	#define M4(x,y,x0,y0) (SQ(x)+SQ(y)<4)?M3(SQ(x)-SQ(y)+(x0),2(x)(y)+(y0),x0,y0):0x60
	#define M5(x,y,x0,y0) (SQ(x)+SQ(y)<4)?M4(SQ(x)-SQ(y)+(x0),2(x)(y)+(y0),x0,y0):0x40

	# Docker networking is messy and undocumented. Docker will create IP addresses and iptables at random times.
	# This can be limited by using totally static IP addresses for network interfaces and avoiding the default network bridge.

	# /etc/default/docker
	# DOCKER_OPTS="--iptables=false --ipv6 --bip 172.16.0.1/16 --fixed-cidr 172.16.0.0/16 --fixed-cidr-v6 2a01:9000::/68"
	# --bip is the host IP address of the docker0 interface
	# --fixed-cidr is the CIDR subnet allocated to the docker0 interface (default network bridge)
	# --fixed-cidr-v6 is the IPv6 CIDR allocated to docker0

	# for IPv6 split your /64 delegated subnet into /68 subnets and allocate them to each docker-compose.yml subnet:

	#include <stdlib.h>
	#include <stdio.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <fcntl.h>
	#include <errno.h>

	int main(int argc, char** argv) {
	int fd;
	off_t ret;

	#https://msdn.microsoft.com/en-us/library/windows/desktop/aa374830.aspx
	$AlternativeNameType = @{
	XCN_CERT_ALT_NAME_UNKNOWN = 0
	XCN_CERT_ALT_NAME_OTHER_NAME = 1
	XCN_CERT_ALT_NAME_RFC822_NAME = 2
	XCN_CERT_ALT_NAME_DNS_NAME = 3
	XCN_CERT_ALT_NAME_DIRECTORY_NAME = 5
	XCN_CERT_ALT_NAME_URL = 7
	XCN_CERT_ALT_NAME_IP_ADDRESS = 8
	XCN_CERT_ALT_NAME_REGISTERED_ID = 9

	# Install ARCH Linux with encrypted file-system and UEFI
	# The official installation guide (https://wiki.archlinux.org/index.php/Installation_Guide) contains a more verbose description.

	# Download the archiso image from https://www.archlinux.org/
	# Copy to a usb-drive
	dd if=archlinux.img of=/dev/sdX bs=16M && sync # on linux

	# Boot from the usb. If the usb fails to boot, make sure that secure boot is disabled in the BIOS configuration.

	# Set swiss-french keymap

	#!/usr/bin/env python
	##############################################################################
	# TODO:
	# * create gnome dock w/ status, pause, and lock-rotation options
	# * documentation
	##############################################################################
	from glob import glob
	import logging
	import os
	import signal