Saturday, May 16, 2020

Review: PCB Fab House PCBWay


A while back I got an offer from PCBWay to test their PB prototyping services. As I was at the time designing a couple of new circuits I accepted their offer and below I will give a description of the process and my impressions.

I like blue silk screens..

This tiny board is white to maximize light reflection. See the previous article for details.

For the test run I used two designs, one that was featured in my last article, and one that is coming up soon.

Disclaimer: I have received these PCBs from PCBWay for review.

Monday, May 4, 2020

Broadlink Smart Bulb Conversion to Open Source


Recently I have come across some smart LED light bulbs that came in different sizes, shapes, functionalities and manufacturers. One thing they share is that they all do their "smarts" over a WiFi connection for which you need to use a smartphone and one of the many apps that help you set up the bulb. Unfortunately, this poses the same serious privacy issue (as I have already shown in a previous article) as for the apps (and the light bulb) to work properly you not only have to be connected to the internet at all times, but you also have to provide sensitive personal data (like your home WiFi network's name, password, your location, etc.) to a 3rd party you know nothing about.

This particular bulb is marketed as "LED Light Bulb" requiring the "Magic Home-Smart home" app for your smart phone.

Under the cover

Wednesday, April 22, 2020

Expert tip: Add More Flash Memory to your Sonoff Basic Wifi Smart Switch


The Sonoff Basic Wi-Fi Smart Switch is an inexpensive wireless smart switch for anyone who wants to remote control and/or automate electric devices around the house or workplace. Unfortunately, it suffers from the same privacy issues as many of the inexpensive consumer grade smart devices, like the one in this article. In addition, the Sonoff Basic only comes with 8Mb (1MB) of flash memory, which makes it even more difficult to use it for development, since this means over-the-air updates are not possible.
Photo borrowed from official site

Monday, March 2, 2020

Privacy Showcase: How to Use Smart Devices without Ewelink/Internet


Recently, more and more consumer devices are available to make your home "smarter". While they can make our lives a bit easier, comfortable, most of these smart devices also give rise to a number of privacy concerns as well as usability/reliability issues:
  • The mobile apps (i.e. Ewelink, Smart life, etc) that come with them are closed source, and as such they should not be trusted. (When launched the first time they start by asking for your wifi network's password, and you can only hope that it doesn't pass it on to 3rd parties...)
  • Internet access is needed for them to operate, and as far as my experience goes in several countries, it is not without interruption.
  • Control happens through some servers over which one has no control or authority. This means that if those servers are down for any reason (a scheduled maintenance, the hosting company's decision to make it a paying service, malicious attack, etc.), then, the best case scenario is you can't control the switch, a worse case scenario is that someone else does.
Image borrowed from the official Sonoff web site

Sunday, February 5, 2017

ActoSenso Server - Controlling it all


Although optional, having a central coordinator (ActoSenso Server) in an automation environment can open up new possibilities. Advantages of having an ActoSenso Server include more processing power, more mass storage (for historical data), easier to develop business logic, etc.

Current setup: RPi 3 and an external hard disk