A short post to save some of the useful options for firewall-cmd:
Centos 7 – firewall-cmd usefull commands
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Author Archives: Paul
Learn about Sigfox and LoRa radio technologies
This post is a VLOG entry, as usual in French, you will find the english text version in the next part of the post.
Basically, I’m explaining how the two LPWAN technologies : Sigfox and LoRa use the radio frequency to communicate with a low power consumption in a wide area environment.
In this video you will find a mix of demonstration with voice to highlight how it works with day-to-day life example and spectrum capture of both technology to visualize how it looks like.
Smart home and wifi pros & cons
Getting this picture from the social networks it was an opportunity on reacting about the general use of wifi technology for IoT smart home equipment and the risk you have to design a such solution.
The following video is a VLOG about this question. As it is in french, this post will details the main lines about my feeling.
Take a look at SigFox radio signals with airspy usb software defined radio
I recently bought an AirSpy mini SDR (Software defined radio) dongle. Understand, it is a radio scanner you connect on your computer able to analyze radio communications on a large frequency range from 24MHz to 1,7HGz. The main difference between this SDR and the low cost one based on RTL 2832 + R820T is the spectrum view up to 6Mhz, the TCXO working with 0,5ppm and globally the quality of the solution and the availability of libraries. What is presented here is also valid for RTL based dongle.
With this tool you can see what is happening on the radio frequencies in real time, compare power, listen radio … This post is presenting how to install it and use it on windows & Mac Os X.
Test of Sigfox Wisol WSSFM10R1 module
I just got them at home ! The new Sigfox module with a low cost approach based on the OnSemi AX-Sigfox-D chip is now ready and available for being delivered. With a price less than $3 per module for a quantity of 10 this module offer a low cost access to the Sigfox network.
In this post I’ll describe the first step with this module.
What about making a $100 market study for your startup ?
Sometime I talk about non tech topic ! And I talk in French … So if you are also interested in an agile way to create a market study, you can watch my talk on this topic 😉
Install mosquitto (mqtt) server on CentOS to publish IoT data
Since a long to time I did not post about MQTT … The main reason was I uses MQTT as a protocol to publish data directly from a device but in a centralized environment like SigFox / LoraWan you can’t use it directly on the device. Actually I have some devices communicating with a backend and the question about how to provide these information to the customers of my service are raising. To match this pattern I have to ways : providing and API where the information are pulled by the customer and MQTT where the information are pushed to the customer.
One choice is not against the other one, I had the two kind of customers. For this reason I will describe how we can implement a MQTT server (mosquitto) to push Sigfox data device as json content.
GPS antenna comparison
I’m using different GPS antennas with different price, size and gain and I had never compared the result in a real live test. So now it is done and the result are good to share.
My test condition are quite bad and we can’t really consider this as a scientific bench but, experimentally it sounds like a real life test.
So the test is to connect an antenna to a TD1204 with a GPS code on it and test the time it makes to fix the position and get some note about signal level, satellites in view… I used in fact 2 TD1204 : one with a reference antenna to ensure we have equivalent condition from one test to the others. The tests are made indoor where the sensitivity is an important factor. This post detail the results.