-------- Forwarded Message -------- From: Kirk Wallace <[email protected]> To: Enhanced Machine Controller (EMC) <[email protected]> Subject: Re: [Emc-users] [OT] Charge Pump Date: Mon, 13 Dec 2010 21:13:10 -0800
On Mon, 2010-12-13 at 20:27 -0600, Karl Schmidt wrote: > Back in the '80s, we used to do something similar that also took care of the > reset pulse width. > (See attached). The values of the C's and Rs set the reset pulse width and > wtdog time. > > We needed to have an ultra reliable system, but problem was that some power > glitches could hang up > processors. Wtdog counters could also get hung up - and we would see it > happen with the early > built-in uP wtdogs. Today they have the bugs out of it for the most part and > if you have a good > power supply and bypassing you won't have problems, yet stray alpha particles > can still sometimes > flip a bit. > > While you can get away with it most of the time, be aware that you can > sometime cause parts to draw > a lot of current if the input isn't supposed to see analog. > > You can get single gate schmitt triggers these days. I saw these earlier: http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=US&WT.z_homepage_link=hp_go_button&KeyWords=tiny+logic&x=0&y=0 (Short URL) http://alturl.com/aft7p I need to get the older larger parts because my older weaker eyes probably can't see these things. > If you are having problems with your system hanging, most likely you have a ground path problem. > Home run grounding with a beefy pavilion ground bus is the best way. My network switches hang whenever there is a glitch in the mains. I have to power cycle them to get them going again. I got my mini ATtiny board today. It's in the attached picture along with a breakout board for an L298 I got from Sparkfun.com . The AVR comes pre-programmed with a data logger. You just plug it into a USB port and it streams voltage data from the ADC's to the application you happen to have open (stdin ?) The screen shot of gedit shows the result. It starts with a blank document and the data steams in as if you were typing it in from the keyboard. It's kind of scary. What if someone had evil intentions. How much could a hacker do through a USB port? I got the AVR to work on a watchdog app, but it's much more entertaining as it is. I blew up a few L298's because I was trying to jury rig them to a breadboard. The L298 pins are too large and they have an odd spacing, so when I saw the breakout boards, I had to have some. It will be nice to be able to tinker with EMC2, albeit with small hardware, but without having to go down the hill to the shop. I guess attachments work, so my ASCII art days might be over. ****** Oops. There is a 90kb attachment limit so my pictures didn't go through. Here they are: http://www.wallacecompany.com/machine_shop/EMC2/AVR/data_logging_avr.png http://www.wallacecompany.com/machine_shop/EMC2/AVR/dcp_6935-1a.jpg -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA ------------------------------------------------------------------------------ Lotusphere 2011 Register now for Lotusphere 2011 and learn how to connect the dots, take your collaborative environment to the next level, and enter the era of Social Business. http://p.sf.net/sfu/lotusphere-d2d _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
