Greetings all; For lack of anything better to do this after noon I set out to cut and assemble the 50 pin jumpers to hook up my purty, all stacked up stairstep style, 7i42TA's. But when I plugged it in, it crowbared the psu. And I'm standing there contemplating my sins when I realize the 7i42TA is bass ackwards, and that I have pin 1 of the 7i90 connected to pin 50 on the 7i42TA's. Duh, so I spent the rest of the day turning the 7i42TA's around, finding there's no way to stack them facing the other way that isn't about an inch and a half too high. So I did stack the firt 2, but set the third on off the end of the 7i90, with the ribbon running under the card to get at the far edge, then brought up over the far end to arrive at the socket on the 7i42TA. There went all my plans to keep the noise on the right end of the 7i90 and beyond, many inches from the pi. Now I have to bring in lots of noise and connect it right on top of the pi. I can't win. It would have been buckets cleaner if the 7i42TA was mirrored so the pin 1's faced each other.
Now, it appears they are being fed not only from the power plugs, but via the 50 pin cables, from the 7i90 also, and I see a jumper that might have an effect on that in the 7i42TA's, so which is the preferred power source giving best performance, Peter? I am thinking I should unplug the power plugs from the 7i42TAs as thats a potential ground loop. I have identified the clock pin on the bottom of the pi, (it's mounted upside down to put the 40 pin adjacent to the 7i90 so that the pin ones mate w/o needing spaghetti knots in the cable, and I've found a 15 pf capacitor I'll stick on it tomorrow for S&G's. Progress? DamnedifIknow. But if it works 100% with the cap installed, I'll then verify the 7i90 is a good one and not one I've already blown with the noise, its box will be assembled and ready to bolt (with electrical insulation to destroy ground loops) to the outside face of the motor driver boxes door by tomorrow night. Then its trace everything and hook it back up again. And howinhell do I lock a kernel version, dpkg, in getting rid of a dependency for a doc file, just ripped out all the realtime stuff and reinstalled the latest raspian 4.9.26 something non realtime kernel. I hope I don't wind up starting all over on this card. dpkg is so slow on this pi things that it will be well past midnight local before I can reboot to a good kernel again. Thats 1h:15minutes elapsed time. And people wonder why I run plumb out of patience. 2 steps fwd, slip and 6 steps back. Sigh... I see the light at the end of the tunnel and it runs me over. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
