On Thu, 2009-10-08 at 10:15 +0100, Andy Pugh wrote: ... snip > I did these sums last night and came to much the same conclusion. I > will see what I have in the way of buffers (I definitely have some > Op-Amps I can configure in voltage-follower mode, but I will see what > the 74LS255 is) ... snip
74LS244 Data: http://media.digikey.com/pdf/Data%20Sheets/Fairchild% 20PDFs/DM74LS244.pdf (Short URL) http://preview.alturl.com/kjp9 I haven't studied the different logic families, so a 74HC244 or HCT or other, might be better. The 4000 series logic can work with 12 or 18 Volts, if needed. The 74LS244 enables can help with blocking the state of the parallel port as the PC boots up. EMC2's watchdog or rather charge pump feature: http://linuxcnc.org/docs/2.3/html/man/man9/charge_pump.9.html can be used to keep the chip from passing signals until EMC2 is up and running. My problem is that I have yet to get a stand-alone charge pump detector working. This worked once, but failed when I tried to make the final board: http://www.wallacecompany.com/machine_shop/Shizuoka/watchdog-1b.png I think I just need to put more effort into understanding how it works in order to adjust the component values. For inverting signals, I have used a 2N3904 or 2N2222: http://www.wallacecompany.com/machine_shop/Shizuoka/watchdog-1b.png to sink a signal to ground. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
