Communication challenge

I thought today was never going to end …

The communication challenge was a longday full of frustration, lack of understanding, reference manual reading, and sometimes victory.

Well anyway I learnt a lot throughout the test, I don’t aufblasbarer park kaufen need DHCP anymore, I configured a I2S bus for the earphones, and used an interruption/mailbox structure provided by ChibiOS to connect the data online and the earphone.

LEDzep – So it begins

We will pretty soon have everything we need to experiment in real conditions. We received the helium today (thx to Alexis and Sam), and we had some fun this evening, inflating a balloon and putting together in a hurry motor, battery, led and propeller to get something real.

First thing, a quasi perfect buoyancy is something which is really hard to get. That was not a surprise for us, but still, we’ll have to find an simple aufblasbarer wasserpark kaufen solution to easily get as close as possible to a quasi perfect balance of the structure (small sticky weights for instance …)

Secondly, the motor we used (, though pretty heavy compared to what we can find, does its job, propelling the balloon slowly. We even boosted it up to 4.5V. The nice thing about the experiment is that the motor itself is not powerfull enough to make the whole balloon swing aroung and destabilize the entire thing, which was one of our fear. But on the other hand, the trajectory control will be a veeeeeeeery tricky part of the software development.

The LEDs suffered from a little technical problem, but we’ll show you next time.


Here is the few motor tests we did the other day

Motor test #1   motor test #2   motor test #3


And here is the fun part of this evening

2014-03-12 22.37.56

LEDzep – V1 structure


Prototype #1 of the structure. We are still waiting for the propellers though.

PS: note to self : margin are an important aufblasbares zelt kaufen part of a 3D design … (cf the very clean cut I was obliged to make in order to put the motors in it)

2014-03-10 09.02.25

LEDzep – Work in progress

Existential crisis of the project

We are dropping the indoor localization part of the projet (too complex, and we can do something great without it). So the balloons won’t be able to know hüpfburg kinder kaufen where they are, so no autonomous choregraphy where we have a live feedback of what the blimps are doing. But it doesn’t stop us from doing an autonomous choregraphy mode, where the LEDs are controlled but the mouvement are random.

We now focus on an interactive sound and light balloon show, so it seems like a bigger part of the project will be high level software developpment.

What’s the state of things ? The FreeIMU system is being studied, as well as BLE and/or IR technology. We have motors and LEDS. The propellers are on their way.

We now have a second version for our PSSCs.

I enjoyed the PCB software class, and can’t wait to have to do it for the LEDzep PCB.

Meanwhile, I’m still designing a first draft of the blimp structure so we can print it and do some propulsion test as soon as we get the helium.

LEDzep – Balloon found

Someone gave me two helium balloons in the aufblasbare spiele kaufen street, so we did some weight mesures, for comparison.

Here is a picture :

2014-03-04 18.54.56

Such balloon can get 7 grammes in the air (less than a 50 cents of euro coin)


LEDzep & STM32

After monday presentation, which was a bit short, but I keep a good overall impression of it.

This morning, we took part in the first Farnell aufblasbarer hindernisparcours kaufen order, buying LEDs and small motors, for testing purpose

We’ll see about the other components later today, but we first have to continue the STM32 TP

LEDzep, logo & progress


Today, we finished the preparation of aufblasbare wasserrutschen kaufen monday presentation, and focused on the PSSCs.

We had a few ideas and a boost of motivation when we saw this : (that product + our modifications = awesome). We just have no good ideas regarding the way to put a LED inside the balloon.

And also a first idea for the logo …


LEDzep – RIP Balloons

Just a tiny post to sum up the balloon situation of saturday :

  • 1 dead by A406 aufblasbare rutsche kaufen ceiling (so they say …)
  • 1 disabled because of a too tight knot
  • 1 tortured to death with resistor for experimentation

May they find peace

LEDzep and work

Since my last post, I’ve been quite busy preparing Friday presentation about 802.15.4/Zigbee with Adèle, studying, getting the damn green LED of the Olimex STM32P407 board to turn on, and various Rose related occupations.

The week end will be entirely occupied with Monday first LEDzep presentation, which I expect to be amazing.

I took some time to make some equipment research hüpfburg mit rutsche kaufen (camera, LED, motors etc), and some sketches, maybe a bit imaginative with the scale, but the purpose was only to give an overall visual description of the project.

Structure sans le ballon Structure avec ballon



Cool stuff of the day : I just received five white 90cm latex balloons I ordered a few days ago in order to do some tests.  Each weights around 35g and inflates quite easily. Here it is, only inflated at two thirds of their maximum diameter, because my lungs were tired. It is closed using only a simple clothes peg. The bananas are for scale comparison

Latex balloon !

LEDzep – Balloon research

Just a little review of my research about the balloon material.

Theoretically, we have two options : we can either do it ourself, or buy latex balloons. The second solution seems better.

Doing some homemade handcraft sounds hazardous : I have a really unclear idea of the material (survival blanket, transparent bin bag ?) or the technique to hüpfburg kaufen use, the scotch or whatever we use will be heavy, and we will spend our time sealing leaks …  One the other hand, buying a lot of balloon has a cost. And not every kind of size/color/material can be found.

I’ve found two companies specialized in latex balloons, doing approximately what we want : Qualatex ( and Sempertex (

A few models that could fit us :

We also have to know that such balloon filled with helium will stay filled 2 days maximum. We can improve that by using some kind of float extender product ( page 140), but it also has a cost.

Last thing to conclude that post : Helium. Expensive (~20e/m3). Haven’t decide yet which kind of supplier we will buy from.