I'm glad you survived. =20 Electron wrote: > >Howdy, > >I'm finally testing my dirk bike ECU. It worked wonderfully till a point, >where the engine turned off and didn't want to start anymore. I thought it >was maybe a bad/cold soldering, so I just replaced it with the original an= d >didn't bother anymore for that day. > >But when back in the lab, the ECU worked! I made a lot of tests and my ECU >proved to work absolutely perfectly, even when hammered. ;) So what was it >that made it suddenly stop working? > >I immediately recalled where it happened (I even have GPS logs): I was in = a >dried river bed full of rocks, and a thick gray cable was making impossibl= e >for me to pass. I stopped in front of it, the engine turned off but I thou= ght >it was just because of carburetion problems (too low idle), etc.. > >I noticed it was a very high tension/current cable that fell down from a >tower. Regardless of that, it felt natural for me to grab it with my hand, >raise it, and thus push the bike beyond the obstacle. Then I tried to star= t >the engine but, as said, it didn't run, so (as I wasn't alone and everybod= y >was in a hurry) I quickly swapped the ECU with the original, and the engin= e >restarted. > >I am thinking to return there but it means to do 200 kms alone.. it's not >safe to do it off road, but thanks to the GPS log I found a way to do 99% = of >those 200km via asphalt, and I will return there to clear my doubts. > >I tried to disturb the ECU in my lab with 230V 2000W appliances, but >evidently that wasn't enough. I will have to return there, near that cable= , >and see if the fault is repeatable, also because I've been using it for >many hours today and it worked flawlessly. > >But as it's very distant from home, I want to make 1 trip and 2 jobs: I wa= nt >to bring with me a 2nd prototype, with a supposed workaround/fix/improveme= nt >in place, and see if this new prototype is immune enough to that terribly = noisy >cable. > >Will shielding help? It probably won't, as it's just 50Hz magnetic field I= think, >but I wish to ask you. > >Will placing the Xtal nearer to the MPU help (currently 10mm), as well as = moving >the Xtal caps to the bottom of the PCB board, so they're as near as possib= le to >the Xtal and MPU too? (currently the caps are on the same PCB side of the = Xtal >and MPU and are comprehensibly not really close (another 10mm) but, worse,= their >ground return doesn't go into the MPU Vss pin, but to the opposite side of= the >PCB). Can this have made a difference? > >What else would you make to ensure maximum immunity to the noise coming fr= om >a very high tension/current cable that is there although it should not be = there? > >It's a chance I have to make my circuit more robust and gain experience be= fore >they fix that cable (because it can't be there, it's dangerous, and I will= notify >the local police about it then, i.e. hopefully tomorrow morning already). > >Oh yes this time I won't touch it, I will reach it near with my bike and E= CU but >not grab it anymore. If it was the cause of the malfunction, it indeed did= it even >at 1 meter of distance, so I'll do it from a small distance. > >Cheers, >Mario > >--=20 >http://www.piclist.com PIC/SX FAQ & list archive >View/change your membership options at >http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .