How do you design these days?
in [Design]
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From: John Larkin on 2 Jan 2010 23:00 On Sat, 02 Jan 2010 21:36:09 -0600, krw <krw(a)att.bizzzzzzzzzzz> wrote: >On Sat, 02 Jan 2010 17:03:43 -0800, John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > >>On Thu, 31 Dec 2009 09:41:54 -0800, "Joel Koltner" >><zapwireDASHgroups(a)yahoo.com> wrote: >> >>>"John Larkin" <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in message >>>news:7glpj5l1a7i5nm45bsp5gfhc016e3kjgo8(a)4ax.com... >>>> On Thu, 31 Dec 2009 09:10:22 -0700, Don Lancaster <don(a)tinaja.com> >>>>>It is NEVER right the first time. >>>> We sell about 80% of our rev A boards, with no prototypes. Assuming >>>> the first unit won't work is self-fulfilling, and a good way to make >>>> sure the third iteration won't work either. >>> >>>I agree with your philosophy John... but you do allow yourself a non-zero >>>number of blue wires or a couple of tack-soldered components or something on >>>those saleable rev. A boards too though, right? >> >>Sure, that happens. But it's supposed to be embarassing. >> >>We make blue boards and I think we should use red wires. But >>production insists on blue. > >I know one company that does use red wires, so oops's stand out like >the sore thumb they are. The Scarlet Letter thing. John
From: krw on 2 Jan 2010 22:59 On Sat, 02 Jan 2010 20:00:23 -0800, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Sat, 02 Jan 2010 21:36:09 -0600, krw <krw(a)att.bizzzzzzzzzzz> wrote: > >>On Sat, 02 Jan 2010 17:03:43 -0800, John Larkin >><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >> >>>On Thu, 31 Dec 2009 09:41:54 -0800, "Joel Koltner" >>><zapwireDASHgroups(a)yahoo.com> wrote: >>> >>>>"John Larkin" <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in message >>>>news:7glpj5l1a7i5nm45bsp5gfhc016e3kjgo8(a)4ax.com... >>>>> On Thu, 31 Dec 2009 09:10:22 -0700, Don Lancaster <don(a)tinaja.com> >>>>>>It is NEVER right the first time. >>>>> We sell about 80% of our rev A boards, with no prototypes. Assuming >>>>> the first unit won't work is self-fulfilling, and a good way to make >>>>> sure the third iteration won't work either. >>>> >>>>I agree with your philosophy John... but you do allow yourself a non-zero >>>>number of blue wires or a couple of tack-soldered components or something on >>>>those saleable rev. A boards too though, right? >>> >>>Sure, that happens. But it's supposed to be embarassing. >>> >>>We make blue boards and I think we should use red wires. But >>>production insists on blue. >> >>I know one company that does use red wires, so oops's stand out like >>the sore thumb they are. > >The Scarlet Letter thing. Exactly.
From: ehsjr on 3 Jan 2010 00:54 krw wrote: <snip> >> >>You've got a steadier hand than I'll ever have. >>I have to do it with a Dremel mounted in a drill press >>adapter, and slide the board against guides clamped to >>the bed. Even then ... :-( > > > Sounds like you need a small milling machine. In my best Clint Eastwood imitation voice: "Go ahead, make me drool". :-) Ed
From: John Devereux on 3 Jan 2010 02:04 John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> writes: > On Fri, 01 Jan 2010 18:33:34 +0000, John Devereux > <john(a)devereux.me.uk> wrote: > >>Bill Sloman <bill.sloman(a)ieee.org> writes: >> >>> On Jan 1, 6:00 am, Spehro Pefhany <speffS...(a)interlogDOTyou.knowwhat> >>> wrote: >>>> On Thu, 31 Dec 2009 09:10:22 -0700, the renowned Don Lancaster [...] >>>> >It is NEVER right the first time. >>>> >>>> Keep firing people who have that attitude and it eventually will be! >>> >>> Perhaps. But if the survivors are sufficiently nervous of getting >>> fired that they triple-check every aspect of the circuit before they >>> commit to a printed circuit layout, you may find that you get to the >>> final layout more slowly than you would have if you'd gone through a >>> throw-away prototype layout along the way. >> >>I'm going through this right now. New (208 pin!) microcontroller, ADC, >>connectors, SMPS chip. I can spend an extra couple of days re-checking >>everything, and I just *know* I will still miss a couple of things. Or I >>can just go ahead and make the damn board. >> >>I think I'll just go ahead and see how it turns out. At some point it's >>actually quicker and cheaper to debug using the real thing. > > You have to debug the real thing anyhow, so it makes sense to try to > do the final product first pass. That saves a lot of time and teaches > good disciplines. And you may be able to sell it. That *is* what I am doing. But don't you find there is eventually a point of diminishing returns with respect to "paper" analysis and prototyping? The last bug you did have on a rev A board, couldn't you have found it by staring at the design for another week, checking datasheets, going through the operation in your head? Maybe prototyping some more bits of the circuit? -- John Devereux
From: Jan Panteltje on 3 Jan 2010 09:58
On a sunny day (Fri, 01 Jan 2010 23:20:29 GMT) it happened Jan Panteltje <pNaonStpealmtje(a)yahoo.com> wrote in <hhm009$nia$1(a)news.albasani.net>: >Here is my old 8052AH BASIC computer that originally controlled everything: > ftp://panteltje.com/pub/8052AH_BASIC_computer/8052AH_BASIC_computer_img_1725.jpg >You can see the 8052AH chip with 'BASIC' written on it just visible next to the flat cable on the right: > ftp://panteltje.com/pub/8052AH_BASIC_computer/8052AH_BASIC_computer_inside_img_1727.jpg >The side slides out, you can then slide in this programmer board for the 8049 EPROM version: > ftp://panteltje.com/pub/8052AH_BASIC_computer/8052AH_BASIC_computer_8049_programmer_board_img_1731.jpg >It has collected a lot of dust, not used for so many years. >On the rear the DIN connector is i2c (external) to all the I/O, there are 2 RS232 connectors, >a power connector, and some extra I/O directly from the 8052 AH pins. > ftp://panteltje.com/pub/8052AH_BASIC_computer/8052AH_BASIC_computer_rear_img_1728.jpg >I wonder if the NICAD (the big yellow thing) is dead after 25 years of no use.... >It is for SRAM backup. >You can also see the pot core for the EPROM programmer voltage generator. >The whole thing runs on a 12 V DC adaptor. >May even try it some day, it should just work with the current system, it still uses the DIN 5 pole to >connect to a cable that connects to the PC. >Computers have something eternal... Hey, I got that old MCS BASIC computer working again:-) grml: ~ # ptlrc -d /dev/ttyS0 -b 1200 Panteltje ptlrc-0.6 using device /dev/ttyS0 Escape exits. *MCS-51(tm) BASIC V1.1* READY >10 for i=0 to 10 >20 print i >30 next i >run 0 1 2 3 4 5 6 7 8 9 10 READY > All I needed to do is solder back some wires to the connectors that were broken.. The NICAD charges and is still working OK! I could no longer find the manual for the 8052AH MCS BASIC, but is not internet and google great: wget www.nomad.ee/micros/Basic52Manual.pdf Nice, an other computer online. Also once wrote an a very simple assembler for that 8052AH, it can output asm in MCS BASIC data statements, so you can speed up parts of the BASIC code: http://panteltje.com/panteltje/newsflex/a52-1.0.tgz |