| Rubem Pechansky 08/09/07 06:23 Read: 341 times Porto Alegre Brazil |
#142978 - Many thanks, I'll try some of your tips... Responding to: Rubem Pechansky's previous message |
...and tell you about any results. Meanwhile what I've done is to mount both micros -- 89S51 AND 89C2051 -- on the same breadboard, each with its own crystal, and make them share the same test buttons (no photos yet). Exchanging crystals made no difference. The 89S51 seems to be far more immune to noise or whatever is causing this.
I've made also a quick-and-dirty test which was connecting pin 5 of the 2051 to one of the S51 oscillator pins. Both worked with no problems. Last test I made was to remove the connection between pin 5 and the S51 and re-insert the crystal as before. Then I removed all caps and this seemed to make the 2051 oscillator work better!!! Did that many times, looks unbelievable but true. But I have to program the micros again as suggested before I come to any conclusions. Many thanks again for now, |
| Topic | Author | Date |
| 89C2051 oscillator does not oscillate (?) | Rubem Pechansky | 08/06/07 17:08 |
| Capacitor value? | Russell Bull | 08/06/07 17:58 |
| 20-40pF indeed | Rubem Pechansky | 08/07/07 08:00 |
| it might be the crystal | Jan Waclawek | 08/07/07 08:05 |
| Probably not | Rubem Pechansky | 08/07/07 08:24 |
| because it\'s crap | Jan Waclawek | 08/07/07 08:31 |
| Not same position | Rubem Pechansky | 08/07/07 08:38 |
| one cap or two makes most probably no difference.. | Jan Waclawek | 08/07/07 09:38 |
| Not on the pins | Rubem Pechansky | 08/07/07 11:45 |
| I'd recomend you re-read the spec's ... | Richard Erlacher | 08/07/07 13:08 |
| It's the same Vcc | Rubem Pechansky | 08/07/07 17:14 |
| Hhm...I wouldn't recommend this paralleling | Kai Klaas | 08/07/07 09:51 |
| hummm... really? In what frequency range? | Jan Waclawek | 08/07/07 10:00 |
| The inductance of the left resonating with... | Kai Klaas | 08/07/07 10:17 |
| interesting | Jan Waclawek | 08/07/07 10:35 |
| Spice models | Kai Klaas | 08/08/07 08:57 |
| Thanks, Kai. | Jan Waclawek | 08/08/07 09:18 |
| Numerical calculation, some examples... | Kai Klaas | 08/09/07 12:09 |
| Wrong reset scheme! | Kai Klaas | 08/06/07 22:24 |
| 10µF reset capacitor to Vcc | Rubem Pechansky | 08/07/07 08:06 |
| Isn't that the mfg's recommended circuit? | Richard Erlacher | 08/07/07 13:10 |
| Which do you mean? | Kai Klaas | 08/08/07 11:43 |
| 10 uF to Vcc and 8.2K (built-in?) to GND | Richard Erlacher | 08/09/07 00:24 |
| no, it is not | Erik Malund | 08/13/07 11:10 |
| If it's in nearly every datasheet ... | Richard Erlacher | 08/13/07 12:55 |
| this is your perception of the things, Richard | Jan Waclawek | 08/13/07 13:04 |
| Here we go again ... | Richard Erlacher | 08/13/07 18:37 |
| ... and again... | Jan Waclawek | 08/13/07 23:22 |
| I don't know what to say ... | Richard Erlacher | 08/14/07 02:50 |
| there is NO out of spec power supply | Jan Waclawek | 08/14/07 03:36 |
| Not only... | Kai Klaas | 08/14/07 07:34 |
| Not allways | Daniel Contarino | 08/15/07 12:24 |
| Have you seen evidence of improvement? | Richard Erlacher | 08/19/07 09:55 |
| Wider spectrum | Kai Klaas | 08/19/07 11:51 |
| maybe ratio of good/bad crystals is the same... | Jan Waclawek | 08/19/07 14:16 |
| In all the various designs I produced ... | Richard Erlacher | 08/19/07 17:10 |
| Never had a failure until now | Grant Beattie | 08/20/07 13:16 |
| I know of lots of crystal problems... | Kai Klaas | 08/21/07 12:02 |
| Could be, but I've never encountered it ... | Richard Erlacher | 08/21/07 12:32 |
| %$#@! Double-post again ... | Richard Erlacher | 08/21/07 12:32 |
| ^%$#@! double-post ... | Richard Erlacher | 08/19/07 09:55 |
| If the datasheet says 1 ms ... | Richard Erlacher | 08/19/07 09:58 |
| more about locomotives | Erik Malund | 08/14/07 06:59 |
| symptoms suggest ... | Richard Erlacher | 08/19/07 10:09 |
| steam locomotives | Erik Malund | 08/13/07 13:15 |
| I like the steam locomotives | Jan Waclawek | 08/13/07 14:26 |
| So do I | Steve M. Taylor | 08/13/07 15:05 |
| me too, said the dog | Erik Malund | 08/13/07 15:10 |
| The kids should be smarter than that! | Richard Erlacher | 08/13/07 18:39 |
| kids are kids | Erik Malund | 08/14/07 06:46 |
| It might not be a clock problem | Stanley Lio | 08/06/07 22:31 |
| Does not work, sorry | Rubem Pechansky | 08/07/07 08:31 |
| Bad Connections or Crystal ? | Richard Houghton | 08/07/07 08:17 |
| A picture may be useful | Rubem Pechansky | 08/07/07 08:28 |
| Breadboards are highly unsuited for micros!! | Kai Klaas | 08/07/07 10:09 |
| Makes sense | Rubem Pechansky | 08/07/07 11:48 |
| breadboards are highly unsuited for ANYTHING! | Richard Erlacher | 08/07/07 13:11 |
| Not at all! | Kai Klaas | 08/07/07 22:26 |
| If you look at the pictures you can see why. | Richard Erlacher | 08/08/07 07:24 |
| Yes, it doesn\'t look properly, but... | Kai Klaas | 08/08/07 08:31 |
| It's too risky! | Richard Erlacher | 08/09/07 00:40 |
| What is the purpose of your posts?? | Kai Klaas | 08/09/07 09:30 |
| My purpose is to point out that there are flaws | Richard Erlacher | 08/09/07 10:43 |
| *** THE PICTURES *** | Rubem Pechansky | 08/07/07 12:04 |
| Problem may be breadboard | Ralph Sac | 08/07/07 12:26 |
| Breadboard correction | Ralph Sac | 08/07/07 16:12 |
| How I programmed the 2051 | Rubem Pechansky | 08/07/07 17:55 |
| Must be continuous | Rubem Pechansky | 08/07/07 17:23 |
| there is a good english word \'IS\" | Erik Malund | 08/13/07 11:11 |
| I have the same thing running on my desk... | Stanley Lio | 08/07/07 20:44 |
| really ? | Erik Malund | 08/13/07 11:41 |
| Sadly, it's a trade name | Richard Erlacher | 08/13/07 12:58 |
yea, but...  | Stanley Lio | 08/14/07 16:31 |
| again, replacing one uncertainty with another | Erik Malund | 08/15/07 07:06 |
| I see two points | Kai Klaas | 08/07/07 22:49 |
| When you\'re ready to give up ... try this! | Richard Erlacher | 08/07/07 13:19 |
| wow | Jan Waclawek | 08/07/07 14:10 |
| use the unbuffered parts | Andy Peters | 08/07/07 14:20 |
| It works fine with S, LS, HC, AC, HCT, ACT, etc | Richard Erlacher | 08/08/07 07:28 |
| It's not so foolproof | Kai Klaas | 08/08/07 09:24 |
| I've had pretty good results ... | Richard Erlacher | 08/09/07 01:02 |
| Many thanks, I'll try some of your tips... | Rubem Pechansky | 08/09/07 06:23 |
| Maybe your AT89C2051 is just damaged? | Kai Klaas | 08/09/07 09:14 |
| Overtone | Darek Rogowski | 08/14/07 07:59 |
| 89S51/52 are much more stable | Rubem Pechansky | 08/21/07 17:38 |
| Can you still (re-) program it | Grant Beattie | 08/16/07 10:37 |
| Let's hope that Rubem will come back ... | Kai Klaas | 08/16/07 22:03 |
| Hi again, sorry | Rubem Pechansky | 08/21/07 16:23 |
| Even with no breadboard | Rubem Pechansky | 09/07/07 18:25 |
| What has the programmer to do with the oscillator? | Richard Erlacher | 09/07/07 22:29 |
| The chip is fine | Rubem Pechansky | 08/21/07 17:36 |
| What will that tell you about the oscillator? | Richard Erlacher | 09/07/07 22:40 |
| It is time to tell the manufacturer, that... | Kai Klaas | 09/08/07 07:42 |
| oscillator of 2051? | Jan Waclawek | 09/08/07 08:48 |
| Sorry, maybe I was too harsh | Kai Klaas | 09/08/07 09:02 |
| The MCU and crystals are all working for sure | Rubem Pechansky | 09/08/07 12:29 |
| It was not the 7805 | Rubem Pechansky | 09/08/07 12:35 |
| because you shook/dropped/kicked it | Erik Malund | 09/10/07 07:01 |
| 7805 decoupling | Jan Waclawek | 09/08/07 13:33 |
| LM79XX need a different treatment! | Kai Klaas | 09/09/07 17:38 |
| Good news | Rubem Pechansky | 09/08/07 14:47 |
| Is this >good news< ?? | Kai Klaas | 09/09/07 17:14 |
| Have you considered the "breadboard" effect? | Richard Erlacher | 09/09/07 17:59 |
| Inductance | David Smith | 09/10/07 04:17 |
| Hey! | Jan Waclawek | 09/10/07 04:24 |
| So what? | Kai Klaas | 09/10/07 09:01 |
| specifically | Erik Malund | 09/10/07 09:11 |
| Let\'s not go overboard ... | Richard Erlacher | 09/10/07 11:05 |
| This does not make him learn to swim... | Kai Klaas | 09/10/07 21:13 |
| I have only my own experience ... | Richard Erlacher | 09/11/07 11:22 |
| Not Atmel problem | James Krushlucki | 09/10/07 23:19 |
| things change | Erik Malund | 09/11/07 06:24 |
| looking at the wrong characteristic | Richard Erlacher | 09/11/07 11:31 |
| OT: to Richard | Jon Ledbetter | 09/11/07 11:54 |
| OT: I hadn\'t but I have ... Yes, I\'m interested! | Richard Erlacher | 09/11/07 18:29 |
| You are probably right | Rubem Pechansky | 09/12/07 20:35 |
| do you have a 10-100nF directly across the | Erik Malund | 09/10/07 06:46 |
| *** PCB and schematic *** | Rubem Pechansky | 09/12/07 21:16 |
| I cannot find C1 | Kai Klaas | 09/12/07 21:28 |
| Ahh, it is the supercap! Needs some changes! | Kai Klaas | 09/12/07 22:07 |
| Surprisingly It works like it is | Rubem Pechansky | 09/13/07 11:01 |
No, no... | Kai Klaas | 09/13/07 21:49 |
| I can't really 'read' your PCB but ... | Erik Malund | 09/13/07 06:02 |
| It is connected | Rubem Pechansky | 09/13/07 11:04 |
| Is any old recipe. | Darek Rogowski | 08/21/07 05:12 |