Posted by: stratolife | September 23, 2008

Late night show

Well, before I climb my bed I will tell you a bit of what I’ve done so far during the last days.

There were a lot of changes. Some steps forward, some steps back.

First of all I can say that we do have two fully soldered and working main boards now. That’s great, but some other things didn’t end up successful like this that far. The first UartMerge I had done and from that I thought it would work did not work when using two boards. Well I found the reason for that (for those who are interested in: I hadn’t realized that the UART-Lines are high on inactivity which made mad problems with the open-collector based OR) and had to redesign and resolde the board almost completely. The new version is not fully tested yet, but receiving from board does work, sending unknown…

The second problem was the extension board. Multiple reasons forced me to redesign it: Support for heaters was needed, cause of heat management, the MOSFETs should be placed at one end of the board so that they can be connected with a cooling plate and – the most important point – I wanted to have the electronic well-arranged in an own box. For that I had to design the board for solid mounting (e.g. add holes for srews). Well, in spite of everything I already successfully finished designing and soldering this board.

Another board that still had to be built was the power board. Because of my new concept for the box (which i already partly realized in some CAD drawings) this board had to be redesigned, too. To save place I integretade the voltage control module. Yeah and this board will be my work for tomorrow, oh sorry, I meant for today. Yes my late night show is a bit to late.

“Yes bed, I’m coming”

You see, my bed is not able to sleep without me, so I have to accompany it. Good night 😉


Posted by: stratolife | September 20, 2008

“Journey” to Operpfaffenhofen…

The last days Alex and I met each other. On tuesday I traveled down to his home and we started merging the boxes with the electronic. But because of having just a few hours we weren’t able to go forward that much.
The next day we drove to the DLR in Operpfaffenhofen to prepare our tests in the vacuum chamber.
It is always very interesting to visit the DLR, in the hall we worked in there was a small rocket exhibited for example and the REXUS teams tested and merged their experiments.
We had some troubles with our equipment and so it was already 10 o’clock when we quit the DLR to drive to a guesthouse where we stayed over night.
On Thursday we started our vacuum tests, with a bit less electronic than we hoped to be able to test. But because of not being able to program our main controller with our laptop the whole electronic was not able to work correctly… (For that reason we will order an usb-programmer for Kiruna to minimize such risks).

When we had finished test and packed in everythin we were shortly able to see the controll centers that were in the same building we were, for example the european columbus module of the ISS is controlled from there, very interesting! Late we drove back to Alex’ home, slept a bit less than we wanted and then I drove back home. Alex went along with me till Frankfurth where he wanted to meet a friend.
On friday evening I finally arrived at Hildesheim (including half an hour DB delay…).

Maybe some more detailed reports about the test will follow but now I have to go on working, PR will come later 😉


Posted by: stratolife | September 13, 2008

Try not to sleep…

After some hard days there is a good progress in electronic. After some small problems I finished and successfully tested the extension board. Further I soldered the board that should merge serial signals from both main boards with galvanic isolation and change levels to RS232 standard. Well, sending form main board worked without any problems but it did not receive any signal from the computer. Two times of improving the schematic and reconnecting conductors ended in successful operation.
Then I also finished programming the voltage detection software for the corresponding board. Thus we should be able to control battery voltage during the flight.
And the most important step: I finished the first final main board and a first test of almost all components has been positive. There should not be any mistake in board layout so I am able to solder the second one. And that’s exactly what im goin to do now… Oh, wait, first of all I will have my breakfast 😉


Posted by: stratolife | September 6, 2008

First status report..

Yesterday the PCBs that are responsible for stearing the whole electronic arrived. Now 4 of them want to be soldered. Almost all other boards are planned and need to be soldered, too. The one that should controll battery voltage already is, the one that should controll the pumps and the blower is currently in soldering process. I’m still waiting for the PCBs fot the 16 temperature sensors and I hope they will arrive today. However, the weekend will be full of tin.
Software for the main board is almost finished, only SDcard support and some small improvements are still missing. Other software e.g. for the voltage control is partly available. The ground controlling software is still in developement, too. It already does work but is not yet very comfortable….
So far so good for the first time… Now I have to take my soldering gun and go on working. Bye 😉