New version of the Telecom design SDK has been released for TD1208 / TD1208R / TD1204 and now officially supporting TD1205.
This new version provide some bug fixes, like a crash after 21285 transmissions that could be after 212 days in case of full use… some I had in touch with could be interested… @pioupiou and also a bug that disable gpio interrupt after sigfox transmission (I experimented it !)
For the main evolution, this version is supporting FCC and TD1508 and improving sigfox transmissions.
From my experience, this version is also a good way to decrease the size of your binary files.
This post is about upgrading from a SDK 5 to SDK6 and the impact you can when recompiling your projects.
To install the SDK from scratch, just follow the well documented official post here.
I’m actually doing some experiment with the French LoraWan network operated by Objenious. To receive the message on your backend application, one of the way is to build a callback function to proceed the data.
Due to LoraWan protocol, you have different type of possible callback like for: joining network, uplink messages and downlink report.
This post gives an exemple on how to implement an uplink message callback handler, with php, for your application backend server.
Today Sigfox is releasing a really good document about antenna design. This pretty document can be found following this link (available on July 7th). This document from TI also contains really well detailed information about the alchemy of antennas and the different kind of product you can find. From Silicon Labs you also have an interesting development kit for 868 antennas with performance published in this application note.
This is to say antenna is one of the most important part of a 868 object, as for Sigfox as for LoRa where the problem is basically the same. I discussed with different sigfox object designed and every-time the antenna was a big project issue. Some has payed about 10-15k€ to get a custom optimized design.
I never experiment a custom design but I made test with various antennas and the purpose of this post will be to give you my feedback on the different solutions.
A second video : this time about “life coding”. They are technics based on reverse engineering to understand how life and DNA is working to create robots ; even if all of this is more biology than computers I was really touched by the Xavier Duportet talk about these technics and what he is doing.
For these reasons, it is the topic of my second youtube video (as the first on it is in French).
To tell you the full story, I was working on a 3d object I want to reproduce. The initial model is a 10cm object. I’ve got a 3D scan of this object and now I want to make a mold to reproduce it with a smaller size (3cm). All should be simple as even my printer software have a resize option.
The problem started when once resized the height of the object has became too small and the precision of the printer does not allow to have a good result. For my need it was not really important to preserve proportion on the Z axis. So I was looking for a tool able to resize an object with a different setting factor for each of the axis.
This tool exists and more over it is really useful for any STL manipulation (at least you need to be a coder) : its name is OpenSCAD. This tool is a programming language for 3D object allowing different object transformation and creation.
For my need to scale X & Y with a 0.4 factor and Z with a 0.6 factor, the following code was the solution :
After making LoRaWan test in a city environment, I make some test in a rural environment with the objective of evaluating the capability for being used in connected farming environment.
The result is really like what we have got in a city, eventually better in a way as the antenna position was on altitude. The following map makes with 6kbps communication shows the coverage. You can see that the coverage is really limited on the Eastern direction. This is due to higher mountains this way. Mountain are the main limiting elements and as you can see, even on short distance communication they are blocking any signal.