| Kai Klaas 08/27/06 09:03 Modified: 08/27/06 09:10 Read: 922 times Germany |
#123138 - Cables... Responding to: Jan Waclawek's previous message |
Jan said:
I thought about it more during the night and I concluded, that for the "bomben- und idioten-fest" version we should ban the "in the DB25 shell" version. Need not to be mounted WITHIN the DB25 shell. You can still solder the DB25 plug to the printed circuit board very easily. If you allow a cable here, then insist on a "printer" cable, which is short, is a flat ribbon cable and has shielding ground wires between the signal lines!! If we finally have to struggle with capacitive cross coupling within an unsuited and superflous printer cable, we should forget the idea of letting a newbie fabricate his own "ISP cable"! Jan said:
In fact, we should strongly discourage using long cables from "the circuit" to the target. Your posts show that this IS a concern. As I recommended series termination, this is not so much of concern compared to circuits omitting them. Nevertheless, it's always good to keep cables as short as possible. More than recommending the newbie to keep the cable short, we should focuse on the importance of having "grounded" shielding wires between the signal lines!!! So, changing the cable or even only the header pinning is a huge NO-NO! Jan said:
However, I still believe it might be a good way. The AT89Sxx inputs, although not exactly Schmitt-trigger, certainly exhibit enough hysteresis to accomodate a slow ramp - it's still the SAME input as used for normal operation, and no slew rate is specified for those in the datasheets, anyway. It's not so much the slew rates of these comparators I concern about, but the propagation delay time! Remember, Atmel's ISP software let the clock line toggle and recieves the MISO signal afterwards. As long as we do not exactly know the delay between the clock signal toggling and the MISO signal recieving we should not add additional delays (neither for the clock signal nor the MISO signal) which are much higher than the original circuit. Some tens of nanoseconds is ok, but hundreds of nanoseconds or even microseconds? Jan said:
Today, I'd expect CMOS inputs with heavy protection and a reasonable amount of hysteresis. I assume the same, but can you rely on it?? Kai |
| Topic | Author | Date |
| SPI ISP issues | Jan Waclawek | 08/13/06 03:00 |
| SPI ISP issues - part 2 | Jan Waclawek | 08/13/06 03:05 |
| SPI ISP issues - part 3 | Jan Waclawek | 08/13/06 04:20 |
| plural | Steve M. Taylor | 08/13/06 05:38 |
| Fora is certainly correct | Phillip M Gallo | 08/14/06 15:44 |
no, it's not ...  | Andy Peters | 08/15/06 01:02 |
| great post! | Phillip M Gallo | 08/15/06 15:02 |
| I think the biggest problem is with the AT | Richard Erlacher | 08/13/06 10:22 |
| maybe | Jan Waclawek | 08/13/06 13:28 |
| It's not necessarily the product ... it's the docs | Richard Erlacher | 08/13/06 16:26 |
| OK let them be so | Jan Waclawek | 08/14/06 07:36 |
| It's true, they shouldn't be used by anyone. | Richard Erlacher | 08/14/06 08:27 |
| What would you suggest to use? | Kai Klaas | 08/14/06 10:58 |
| Anything else at all would be fine ... even a PIC | Richard Erlacher | 08/14/06 15:58 |
| Whaaaat??? | Jan Waclawek | 08/14/06 16:05 |
| ANYTHING but Atmel products! | Richard Erlacher | 08/14/06 23:23 |
| Come on, Richard... | Kai Klaas | 08/15/06 08:39 |
| well, I, for one, agree with Richard | Erik Malund | 08/15/06 08:44 |
| Bullshit! Stating such is entirely ridiculous! | Kai Klaas | 08/15/06 10:43 |
| how can a FACT be \\\'ridiculous\\\"? | Erik Malund | 08/15/06 10:49 |
| It's ridiculous, because you deduce... | Kai Klaas | 08/15/06 11:07 |
| single event? | Erik Malund | 08/15/06 11:19 |
| Yes, and hundreds of events with Philips, | Kai Klaas | 08/15/06 11:42 |
| a VERY high up 'idiot' | Erik Malund | 08/16/06 07:01 |
| Well, mine was a long series of events | Richard Erlacher | 08/15/06 16:49 |
| there may be hope, sorry Kai | Erik Malund | 08/17/06 12:05 |
| It will be a WARM December day in Moscow | Richard Erlacher | 08/17/06 17:08 |
| maybe someone found out | Erik Malund | 08/18/06 06:28 |
| The penalty isn't severe enough | Richard Erlacher | 08/18/06 12:01 |
| blame the rest of the bunch | Erik Malund | 08/18/06 12:52 |
| Well, as I said, it's like U.S.-made cars | Richard Erlacher | 08/18/06 16:41 |
| If they'll do it to US, they'll do it to YOU! | Richard Erlacher | 08/15/06 10:44 |
| Do you really think that others are better?? | Kai Klaas | 08/15/06 11:03 |
| all comapanies have things to blame them for | Erik Malund | 08/15/06 11:18 |
| Indeed! | Kai Klaas | 08/15/06 11:36 |
| a maxim about maxim | Andy Peters | 08/15/06 12:17 |
| Once upon a time ... there were second sources ... | Richard Erlacher | 08/15/06 16:56 |
| I don't love Philips, either | Richard Erlacher | 08/15/06 16:51 |
| I don't 'love' any company, but I 'love' to work w | Erik Malund | 08/16/06 07:19 |
| Once upon a time there were FAE's who knew things. | Richard Erlacher | 08/16/06 09:43 |
| once upon a time ... | Erik Malund | 08/16/06 10:54 |
| Yes, it\'s like the grocery store | Richard Erlacher | 08/16/06 14:23 |
| The biggest problem is | Kai Klaas | 08/14/06 07:44 |
| do it - under my name | Jan Waclawek | 08/14/06 08:33 |
| All right, here is it... | Kai Klaas | 08/18/06 21:49 |
| Kai .. we're not getting a bit sensitive here ? | Phillip M Gallo | 08/19/06 00:41 |
| noooooo................ hmm, maybe a bit... | Kai Klaas | 08/19/06 23:07 |
| Why does this come up so frequently? | Richard Erlacher | 08/19/06 23:19 |
| Because there is so much trash in the www! | Kai Klaas | 08/21/06 10:21 |
| Maybe we can provide a local "fix" for that | Richard Erlacher | 08/21/06 10:38 |
| Great idea, but... | Kai Klaas | 08/21/06 22:04 |
| the other side of the coin | Erik Malund | 08/22/06 06:10 |
| A fool who trusts on phantasy programmers | Kai Klaas | 08/22/06 07:46 |
| Kai the issue is | Erik Malund | 08/22/06 08:02 |
| Exactly! | Kai Klaas | 08/22/06 09:14 |
| Little Joe | Jon Ledbetter | 08/22/06 09:26 |
| did you not know | Erik Malund | 08/22/06 09:44 |
| especially since he\'s been deceased for some time | Richard Erlacher | 08/22/06 09:58 |
| Lots of those "fantasy" programmers are for sale | Richard Erlacher | 08/22/06 09:57 |
| What a trash! | Kai Klaas | 08/22/06 22:23 |
| Oddly enough, similar circuits work for JTAG | Richard Erlacher | 08/22/06 22:31 |
| Driving cables is nasty!! | Kai Klaas | 08/22/06 22:53 |
| framkly, I wish eval-board makers would heed this | Richard Erlacher | 08/22/06 23:16 |
| Have you tested series termination? | Kai Klaas | 08/23/06 10:16 |
| would be great, but | Erik Malund | 08/23/06 10:36 |
| Kai, I think that would be a WONDERFUL addition! | Richard Erlacher | 08/23/06 12:52 |
| Well, what I am thinking ... | Richard Erlacher | 08/22/06 10:11 |
| Yeah, but what's that to do with ISP? | Jon Ledbetter | 08/22/06 10:20 |
| grits, yes, oatmeal, no | Erik Malund | 08/22/06 10:21 |
| Some of 'em will look, read, and do SOME work | Richard Erlacher | 08/22/06 17:57 |
| and the winner is | Erik Malund | 08/23/06 05:56 |
| An alternative to Atmels ISP CABLE | Kai Klaas | 08/20/06 22:46 |
| Profiting from highest noise margins | Kai Klaas | 08/21/06 10:15 |
| comparator | Jan Waclawek | 08/25/06 17:07 |
| Not so well suited... | Kai Klaas | 08/26/06 08:28 |
| I don't understand. | Jan Waclawek | 08/26/06 15:39 |
| Check the spec-sheets | Richard Erlacher | 08/26/06 17:35 |
| I am sorry... | Kai Klaas | 08/26/06 21:10 |
| cables et al | Jan Waclawek | 08/27/06 00:57 |
| Cables... | Kai Klaas | 08/27/06 09:03 |
| software | Jan Waclawek | 08/27/06 15:09 |
| ps | Jan Waclawek | 08/27/06 16:17 |
| To be honest... | Kai Klaas | 08/27/06 20:12 |
| Atmel software... a piece of @%^& | Jan Waclawek | 08/28/06 04:02 |
| it's for amateurs | Erik Malund | 08/28/06 06:58 |
| ?? | Kai Klaas | 08/28/06 07:20 |
| Not at all | Kai Klaas | 08/28/06 07:19 |
| dear amateurs, be realistic | Erik Malund | 08/28/06 08:02 |
| Erik, did you mean... | Jan Waclawek | 08/28/06 09:24 |
| Why, oh, why | Erik Malund | 08/28/06 09:39 |
| why, oh why | Jan Waclawek | 08/28/06 09:45 |
| not the issue | Erik Malund | 08/28/06 10:32 |
| but you ARE professional!!!! | Jan Waclawek | 08/28/06 09:39 |
| now, I'm going to upset Richard | Erik Malund | 08/28/06 09:44 |
| ICE? | Jan Waclawek | 08/28/06 09:51 |
| No success stories | Maarten Brock | 08/28/06 12:28 |
| Exactly! | Kai Klaas | 08/28/06 20:48 |
| Grrrr! Well, maybe not this time ... | Richard Erlacher | 08/28/06 12:35 |
| it makes you wonder, doesn't it? | Richard Erlacher | 08/28/06 12:28 |
| ATMEL cable with the HC | Jan Waclawek | 08/28/06 09:49 |
| another idea | Jan Waclawek | 08/29/06 06:58 |
| please, pretty please | Erik Malund | 08/29/06 07:22 |
| there is no magic | Jan Waclawek | 08/29/06 07:32 |
| you said it | Erik Malund | 08/29/06 07:47 |
| you got me wrong | Jan Waclawek | 08/29/06 07:53 |
| do not blame me for what YOU said :) | Erik Malund | 08/29/06 08:04 |
| teaching is hard | Jan Waclawek | 08/29/06 08:32 |
| good analogy, the question is | Erik Malund | 08/29/06 08:47 |
| when I turned my back... | Jan Waclawek | 08/29/06 09:07 |
| you forgot | Erik Malund | 08/29/06 09:14 |
| filter | Jan Waclawek | 08/29/06 09:19 |
| nope | Erik Malund | 08/29/06 09:25 |
| upside-down | Jan Waclawek | 08/29/06 07:49 |
| and the 3rd reader | Erik Malund | 08/29/06 07:57 |
| he already did | Jan Waclawek | 08/29/06 08:14 |
| a good one | Erik Malund | 08/29/06 08:51 |
| tell it beforehand | Jan Waclawek | 08/29/06 09:11 |
| The newbie SHALL try to build his stuff, but... | Kai Klaas | 08/29/06 09:24 |
| allow a reply of \"you stupid idiot\" to anyone | Erik Malund | 08/29/06 09:33 |
| Will not do the trick, unfortunately | Kai Klaas | 08/29/06 09:14 |
| decoupling the LPT lines? | Jan Waclawek | 08/29/06 09:41 |
| Low state noise margin... | Kai Klaas | 08/29/06 09:43 |
| and with a Schottky? | Jan Waclawek | 08/29/06 09:53 |
| No, I wouldn't recommend this | Kai Klaas | 08/29/06 21:04 |
| www.reichelt.de | Jan Waclawek | 08/30/06 02:02 |
| Ok, to be more precisely... | Kai Klaas | 08/30/06 09:28 |
| can you please draw it down? | Jan Waclawek | 08/30/06 11:46 |
| Replace the 74VHC244 in the original circuit | Kai Klaas | 08/30/06 12:03 |
| How would a germanium work? | Richard Erlacher | 08/29/06 22:10 |
| Could work! | Kai Klaas | 08/29/06 22:34 |
| thanks, Kai! | Jan Waclawek | 08/25/06 16:58 |
| Schottky diodes | Kai Klaas | 08/26/06 21:29 |
| to Schottky or not to Schottky :-) | Jan Waclawek | 08/27/06 00:46 |
| Yes, but we must assume a minimum standard... | Kai Klaas | 08/27/06 08:32 |
| shopping | Jan Waclawek | 08/27/06 14:57 |
| My point is.. | Kai Klaas | 08/27/06 20:06 |
| You can use an array | Richard Erlacher | 08/27/06 12:25 |
| Your search - 74S1023 - did not match any document | Jan Waclawek | 08/27/06 15:03 |
| SN74S1053 | Kai Klaas | 08/27/06 19:54 |
| OOPS! it is 74S1053 ... sorry! | Richard Erlacher | 08/27/06 22:29 |
| the issues | Erik Malund | 08/15/06 07:50 |
| a most telling thread | Erik Malund | 08/15/06 09:11 |
| The root problem is that the first thing one needs | Richard Erlacher | 08/15/06 17:02 |
| "dedicated programmer" | Jan Waclawek | 08/31/06 02:50 |
| what's difficult to understand ... | Richard Erlacher | 08/31/06 08:03 |
| Ok, how do you propose they program and erase the | Erik Malund | 08/31/06 08:27 |
| I would not be quite so sure about that | Jan Waclawek | 08/31/06 08:43 |
| Keep in mind that this is for newbies ... | Richard Erlacher | 08/31/06 12:29 |
| but they still have to build it | Erik Malund | 08/31/06 13:45 |
| Only because it looks simple does not mean... | Kai Klaas | 08/31/06 14:33 |
| he's desperate | Erik Malund | 08/31/06 15:19 |
| there are lots of circuits published like this! | Richard Erlacher | 08/31/06 16:41 |
| I used to have memory mapped I/O in virtual | Erik Malund | 09/01/06 06:23 |
| I wouldn't say that ... | Richard Erlacher | 09/01/06 09:00 |
| that threy learn to drive with a stick shift | Erik Malund | 09/01/06 09:40 |
| Once again, you are exaggerating ... | Richard Erlacher | 09/01/06 09:59 |
| the point I\'m trying to make (and believe that I | Erik Malund | 09/01/06 10:46 |
| Yes, but in 101 you've got to use a '51 or '31 | Richard Erlacher | 09/01/06 13:47 |
| nonono | Jan Waclawek | 09/01/06 14:16 |
| Perhaps you\'re right, in this case ... | Richard Erlacher | 09/01/06 14:40 |
| I don't think so | Jan Waclawek | 09/01/06 15:21 |
| Ah but.. | Steve M. Taylor | 09/03/06 21:00 |
| halelujah! | Erik Malund | 09/05/06 09:51 |
| the problem with RD2 is... | Jan Waclawek | 09/01/06 14:17 |
| what cost the most | Erik Malund | 09/05/06 09:58 |
| cost | Jan Waclawek | 09/06/06 08:40 |
| patience is what it takes | Richard Erlacher | 09/06/06 15:57 |
| let's sort it out | Jan Waclawek | 09/06/06 08:52 |
| Richard, you aregue things that, while valuable , | Erik Malund | 09/05/06 09:56 |
| Its not the cables if you ask me. | Jez Smith | 09/06/06 15:25 |
| an interesting thought | Erik Malund | 09/06/06 15:39 |
| It's probably not JUST this part ... | Richard Erlacher | 09/06/06 16:01 |
| not the cable alone | Jan Waclawek | 09/07/06 01:00 |
| it will, but | Erik Malund | 09/07/06 06:34 |
| It simply has to do with the numbers | Kai Klaas | 09/07/06 09:02 |
| maybe not quite ... | Richard Erlacher | 09/07/06 09:33 |
| I was assuming... | Kai Klaas | 09/07/06 09:58 |
| a case like that ... | Richard Erlacher | 09/07/06 11:32 |
| I have | Erik Malund | 09/07/06 11:43 |
| Perhaps it's that the approach is wrong | Richard Erlacher | 09/07/06 15:29 |
| I guess I have seen those ... | Richard Erlacher | 09/18/06 10:37 |
| fresh thoughts | Jan Waclawek | 09/18/06 07:52 |
| ??????????????? | Kai Klaas | 09/18/06 11:03 |
| I'm puzzled, too, Jan | Richard Erlacher | 09/19/06 08:57 |
| 2 different things | Jan Waclawek | 09/19/06 11:49 |
| au contraire | Erik Malund | 09/19/06 11:53 |
| from the ISP point of view... | Jan Waclawek | 09/19/06 12:13 |
| if you have "no reset and oscillator" | Erik Malund | 09/19/06 12:29 |
| sure | Jan Waclawek | 09/19/06 12:36 |
| Ok \"in-situ programming\" works but that is not ISP | Erik Malund | 09/19/06 12:51 |
| Does this scheme actually work reliably? | Richard Erlacher | 09/19/06 13:32 |
| Guiness book? | Erik Malund | 09/19/06 13:46 |
| This all goes back to the "AT" in the part number | Richard Erlacher | 09/19/06 14:59 |
| Nothing magic with reset and oscillator | Kai Klaas | 09/19/06 20:27 |
| I am talking about the rusty nail | Jan Waclawek | 09/20/06 01:19 |
| Yes, here you are right! | Kai Klaas | 09/20/06 08:10 |
| just helping | Erik Malund | 09/20/06 08:42 |
| 200 | Steve M. Taylor | 09/20/06 09:59 |
| not quite, but I like the idea | Jan Waclawek | 09/20/06 11:50 |
| Exactly! | Kai Klaas | 09/20/06 12:34 |
| ... and that's why I advocate for the 8032 version | Richard Erlacher | 09/20/06 22:13 |
| Stuff it | Steve M. Taylor | 09/20/06 23:40 |
| This will soon be moot | Erik Malund | 09/21/06 07:05 |
| Central Europe? | Jan Waclawek | 09/21/06 07:28 |
| Mistake... | Kai Klaas | 09/21/06 08:06 |
| you think so, I do not | Erik Malund | 09/21/06 08:13 |
| Better hope... | Kai Klaas | 09/21/06 08:31 |
| no love there | Erik Malund | 09/21/06 08:44 |
| Nothing is perfect... | Jan Waclawek | 09/22/06 01:24 |
| HUH | Erik Malund | 09/22/06 06:27 |
| waitaminute | Jan Waclawek | 09/22/06 06:43 |
| same desert | Erik Malund | 09/22/06 06:56 |
| it appears so | Jan Waclawek | 09/22/06 07:00 |
| male cow manure | Erik Malund | 09/21/06 06:57 |
| Eprom programmers are cheap and simple | Richard Erlacher | 09/21/06 10:46 |
| Cheaper than a $25 Atmel cable ? | Erik Malund | 09/21/06 11:17 |
| Yes, and widely applicable, too | Richard Erlacher | 09/22/06 10:05 |
| beware | Erik Malund | 09/22/06 11:12 |
| That's the usual line from an Asian vendor in U.S. | Richard Erlacher | 09/22/06 14:09 |
| fresh experience | Jan Waclawek | 09/26/06 02:26 |
| I am not going to vote 'off topic' but | Erik Malund | 09/26/06 06:26 |
| I am still just thinking aloud... | Jan Waclawek | 09/26/06 07:27 |
| just helping | Jez Smith | 09/26/06 07:50 |
| 222 posts WOW!! | Jez Smith | 09/26/06 07:51 |
| EEEK! Why would you get that close? | Richard Erlacher | 09/26/06 10:44 |
| post number 224 and counting | Jez Smith | 09/27/06 09:49 |
| Well, I\'m a dog person ... | Richard Erlacher | 09/27/06 11:37 |
| 226 | Erik Malund | 09/27/06 11:41 |
| tie a brick around his neck | Richard Erlacher | 09/27/06 11:54 |
| %$#@! it happened again! | Richard Erlacher | 09/27/06 11:55 |
| Programming Dogs | Jon Ledbetter | 09/27/06 12:52 |
230 tried it | Erik Malund | 09/27/06 13:00 |