Santa Claus has passed!

It was a hassle. It took a month of ruthless struggle, juggling sales reps, quotes and paperwork. Relaunch, wait, relaunch, wait...

I even needed to be loaned a SIRET number so that the "accounts receivable" department can validate this damn order.

But finally, it finally happened:

Better than the #Valentine's day is #Christmas! Full of modems @Sigfox in the mailbox #TD1208 #IoT #GeekPorn pic.twitter.com/Y8DHN0gbEl

— Nicolas BALDECK (@nb4ld) February 14 2014

They are not beautiful these TD1208 ?

In this small rectangle of 25x13x4mm, we find all the intelligence of the beacon:

• a processor ARM Cortex M3, a small but powerful brain
• the radio module that manages all Sigfox communication

Everything is integrated. The sensors, the energy and the antenna are directly connected to it; he is injected with a little home-made program; and hop, we have our beacon 🙂 Even better than one Arduino.

Now that I have this, I will finally be able to get down to business.

(I'm still waiting for the delivery of the interface J-LINK to be able to program and debug all this)

It gas?

I have a small stock of BMP180. This is a pressure and temperature sensor manufactured by BOSCH. As it's originally designed for smartphones, it's tiny, cheap and the electrical consumption is around a few microphone-Amps.

I'm looking for a small place to embed it in the tag. That way I can use the measurement to improve the paragliding weather forecasts.

You receive me ?

The big difficulty with Sigfox is the design of the antenna. 

Indeed, we are sending very weak signals. About 20mW. This is the same strength as your computer's wifi signal.

Except that where your wifi hardly exceeds a few walls, the sigfox signal is supposed to carry up to 40km!

Once arrived at the Sigfox relay antennas, the signals are extremely weak. Up to -146dBm, or 0,0000000000000000025 Watts!!!

In other words, you have to think a little about the design of the antenna. Because if the antenna is not perfectly adjusted, we can easily lose a large part of this tiny energy.

This is a problem that I had not anticipated well, and which complicates things quite a bit. Installing an antenna is easy. But making yourself an antenna that is completely integrated inside the anemo is another problem.

Fortunately, I was able to take advantage of my Météo-France training last week in Toulouse to make a small detour to Sigfox. I talked to one of their ultra-competent engineers, and we found a solution to this antenna issue.

Ici, un super proof of concept 🙂

Um, the disgusting antenna made in a hurry with a stainless steel hanger. Not very @sigfox-certified, does it pass! pic.twitter.com/sL9RhKAC7A

— Nicolas BALDECK (@nb4ld) February 14 2014

Well in real life it will be a little more professional. I have an appointment in a lab next week to work it out with some real gear. The kind of must-have toys kind network analyzer but that I don't have at home because it costs €30.

Bip-Bip

To my mini-conf opened on Monday, there were a few paragliders who got lost there. In particular a certain Timothée, better known in underground hang-gliding circles as the gentleman who makes the Bip-Bip.

And so this gentleman kindly offered me some help. To make matters worse, he lives right next to my office. Damn then!

SPV1050

Behind this barbaric name hides a super chip manufactured by ST Microelectronics. " Ultra low power energy harvester and battery charger with embedded MPPT and LDOs " as they say.

Obviously, I dream of integrating that into my beacons, to do all the energy regulation work, the battery, the solar panel and everything.

The only thing is that it is too new, not yet available. They announced it last December. So it shouldn't take too long, I hope. Otherwise too bad, we will do without.

In summary: work, work and more work!

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This article tells you about the birth of Piou Piou, the first 100% autonomous and affordable sensor to measure the wind live, even where there is no electricity or internet.

Discover Pioupiou on his website: http://pioupiou.fr