[Paparazzi-devel] Blown power supply - again

[Jesper Kempe]

Hi all

Progress is slow for me to get my Tiny 2.11 to control my plane. New plane btw cause my first one created a small dent in the tarmac of landing strip when I should recover it from Auto1 but insted set the switch to Auto2...

Anyway, a couple of months ago the power module of my Tiny went up in smoke. I managed to replace it with a new one and I also then thought I had found the problem why that happend. I still had the +5V from the ECS connected to back to the Tiny. 
That wire was cut and then I took the plane for a testflight but then the crash mention obove happend.
Apart from the plane, the Xbee modem was broken. But also the power module was sort of shaved of the Tiny board as the board was pushed backward in the plane and into a a part of the airframe...

Once again I replace the power module and I hooked up everything and did some ground tests. This test was done with 3 cells LiPo but just before the flight I switch to a 4 cells that I had used earlier to fly (and tested the Tiny with). When I connected the battery the bad sound of a short was heard and the smell of burnt electronic started to apear. 

For the third time I replaced the power module and this time I actually managed to get some flight time for the system. But during flight I noticed I had som bad interference in the servos so I quickly landed. I started to disconnect things to locate the problem and I found that it was when the Tiny was to close to the reciever I got this problem. To test how close I could have I powered up the plane with standard Rc configuration (no Tiny or Xbee) and then I should connect power to the Tiny - That nasty sound and smell again! The third power module was blown

Does anyone have any ideas on what might be wrong with my system? I do have nice +5V out from the module but I did notice something the last time. That was that the voltage of the battery was now shown in the Ground station as it did earlier. Before I removed the module I tried to check connection from pin 1 of the module to the resistor R1 but it was no connection. Probably I have damaged the board with all my soldering. Can this (and maybe if it happend to for example pin 4 also) have caused my problems?

Looking at Fedex tracking site now and my new module should arrive this afternoon. Thank good for TI free samples.... :-)

//Jesper