FOTA: Firmware Over The Air

When prototyping and writing the first version of the firmware you rarely spend a lot of time thinking about updating it; the focus is mainly on getting everything to work. After that you start ironing out all the other issues like watchdogs, logging, power hogs and correct behaviour whenever you loose connectivity or something not on the happy path and finally the first version is ready to be deployed. If you are lucky you might have just a few test devices in relatively close proximity that can be fixed whenever something in the real world isn't quite what you hoped it would be. »

Using CoAP on SARA N2 NB-IoT modules

UDP packets are generally nice but there's one thing they are: Datagrams. You can't tell for sure that they have been delivered or when. Usually this is solved by saying “use TCP if you want flow control” but when you are working on NB-IoT modules that might not be an option. The problem If you are sending UDP packets with the SARA N2 module you generally don't know what will happen with the data once it is sent. »

The Chemistry of Powder and Explosives...

…does not stop when the visual effects subside. In order to make fireworks displays more interesting, chemicals are added to the propellant / powder mix. Igniting these mixtures produce varius incandescent and luminous effects during combustion. Byproducts from the chemical reactions that take place are areosols and a cocktail of more or less toxic gases. Typical compounds that are found in the aerosols are: Aluminium oxide, ammonium carbonate, Antimony(III) oxide, barium carbonate, barium sulphate, Bismuth(III) oxide, carbon, Copper(II) oxide, Iron(III) oxide, Magnesium oxide, potassium chloride, Potassium oxide, Potassium carbonate, Potassium nitrate, Potassium sulfate, Potassium sulfide, Potassium sulfite, Potassium thiocyanate, Strontium carbonate, Strontium sulfate, Sulphur, Titanium(II) oxide [1] - in order to name a few. »

Let's start a conversation

A feature we had to sacrifice on the “getting done in time” altar was the downstream messaging (ie sending messages to the devices, not just receiving). We had a clear idea on how we should do it, but our main focus was to get the essentials up and running so we had to postpone it a bit. As with any LPWAN technology the first thing you'll try is to get bytes through the system, then something slightly more useful like monitoring data but after a while you realise that you'll need downstream messaging to really make it a useful technology. »