Eka Puji Widiyanto ekapujiw2002

Packet format

0xfe - start byte
0xea - some kind of protocol version
0x10 - some kind of protocol version
1 byte of packet length, payload length + 4
variable length payload

Setup nut and netdata on Ubuntu

In this document, I will explain how to setup nut (Network UPS Tools) on Ubuntu 18.04 and 20.04.

It is basically the next chapter of my previous gist, Upgrade nut on Ubuntu 18.04.

I'll only document USB connected UPS and not the other supported connection modes.

Install required dependencies

MQTT in your browser

MQTT is probably best known as a lightweight messaging protocol implemented for small sensors, but there is actually a JavaScript implementation called MQTT.js. It's a JavaScript implementation, so of course it works in a browser. I think it's a great option for front-end engineers who are working with MQTT/IoT-related projects (for example, creating a dashboard to visualize MQTT data). In this article, I'd like to write about what I did when I tried to connect MQTT.js to the test server (broker) of Mosquitto™.

之前在这里研究过的用iptables配置跨网段的端口转发

Assume we have the following network environments:

Device:
- eth0 (192.168.6.59): for external access
- enx000ec6a490c5 (192.168.1.2): for ip camera
IP Camera：192.168.1.10
PC：192.168.6.2

Copying the whole linux root filesystem locally or remotely using rsync

Explanation of chosen options:

Verbose output with speed and progress information
Try to preserve all possible information: file attrs, hardlinks, ACLs and extended attrs,
Exclude contents of pseudo-filesystems and mountpoints
In this example source host is remote and destination local.

rsync --info=progress2  -vaHAX --exclude={"/dev/*","/proc/*","/sys/*","/tmp/*","/run/*","/mnt/*","/media/*","/lost+found"} source.host:/ /local/destination

	Basic Manual for DaFit Fitness Tracker firmware update protocol, works for nearly any nRF52832 tracker from Company DaFit

	The minimum size of update file is 0x10000(can be filled with garbage to get to size) and the maximum size is 0x2F000
	the update will first get stored onto the external flash at position 0x3D1000 by the stock firmware(not by the bootloader)
	the size of the update will get stored at 0x3D0000 on external flash with 4 bytes uint32_t

	when bootloader gets activated it will copy the update from external flash to 0x23000 of the nRF52 internal flash.


	Connect to device,

	server {
	server_name house.example.net;
	listen 1.2.3.4:80 default_server;
	listen [2001:1234:ffff::1]:80 default_server;

	add_header Cache-Control "public,max-age=31536000";
	return 301 https://$server_name$request_uri;
	}

	map $ssl_client_s_dn $ssl_username {


	/**
	ESPNOW - Basic communication - Broadcast
	Date: 28th September 2017
	Original Author: Arvind Ravulavaru <https://github.com/arvindr21>
	modified by Daniel de kock
	Purpose: ESPNow Communication using Broadcast

	Resources: (A bit outdated)
	a. https://espressif.com/sites/default/files/documentation/esp-now_user_guide_en.pdf

	import asyncio
	from collections.abc import Coroutine
	from typing import Any


	async def gather_limit(
	*tasks: Coroutine[None, None, Any],
	return_exceptions: bool = False,
	max_con: int = 100,
	) -> Any: