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Kai Klaas
08/29/03 08:50
Read: 858 times

#53655 - RE: ALE---indicator...failed MPU
Responding to: Stanley Lio's previous message
Hallo Stanley,

a picture tells more than 1000 words, right?

Now I have an idea, why you have problems with your microcontroller. Sorry, but there's no other option, you MUST fabricate microcontroller circuit much more compact. With zero force socket, adequate power supply decoupling is impossible! Also, oscillator pins are much too far away from crystal. Please avoid this zero force socket for standardly running of microcontroller. It may be adequate for programming, when clock is reduced, and even more important, when no loads with long, unshielded and unfiltered cables are connected.

So, my recommendation is to use simple socket. Put power supply decoupling capacitor as close as possible to microcontroller. But now problems arise: If you don't have solide massplane, but connect decoupling capacitor by wires, decoupling looses almost all of it's functionality!! Inductivity of wires are so much higher than solid massplane, that you will always have problems...Such an arrangement will NEVER work reliably, especially if you use DIL-package. PLCC package would introduce some benefit. But what you really need is wide copper traces of a properly fabricated PCB, which highly reduce inductivity of 0V routing.

Another point: I assume you connect cables to driver unit without any filter or buffer. That's very dangerous, because port outputs of microcontroller are very high impedant, when showing logical high. So, any interefence reaching cables is coupled into microcontroller and makes nonsense.
Before you route your cables to driver unit, do buffer them directly at microcontroller, insert a filter and shield cables. Please have a look again at my schematic, where I realized and explained all these very important points!!

By the way, use of integrated bridge-driver will NOT solve your problems. Just the opposite, if it's a fast one, problems will even getting worse.

If you don't understand my reply in detail, don't hesitate to contact me directly. Put your cursor on my name at upper left of screen and you will find my e-mail address.


List of 51 messages in thread
ALE---indicator...failed MPU      Stanley Lio      08/22/03 10:15      
   RE: ALE---indicator...failed MPU      Kai Klaas      08/22/03 10:18      
      RE: ALE---indicator...failed MPU      Stanley Lio      08/23/03 10:48      
   RE: ALE---indicator...failed MPU      Oleg Sergeev      08/22/03 10:20      
   RE: ALE---indicator...failed MPU      Andy Neil      08/22/03 10:55      
      RE: ALE---indicator...failed MPU      Stanley Lio      08/23/03 10:50      
   RE: ALE---indicator...failed MPU      Raghunathan R      08/22/03 11:11      
      RE: ALE---indicator...failed MPU      Stanley Lio      08/23/03 10:47      
      RE: ALE---indicator...failed MPU      Abhishek Singh      08/23/03 10:57      
   RE: ALE---indicator...failed MPU      Stanley Lio      08/23/03 11:04      
   RE: ALE---indicator...failed MPU      Stanley Lio      08/23/03 11:05      
      RE: ALE---indicator...failed MPU      Oleg Sergeev      08/23/03 14:12      
         RE: ALE---indicator...failed MPU      Raghunathan R      08/23/03 20:35      
            RE: ALE---indicator...failed MPU      Kai Klaas      08/23/03 21:43      
               RE: ALE---indicator...failed MPU      Stanley Lio      08/23/03 22:53      
                  RE: ALE---indicator...failed MPU      Abhishek Singh      08/24/03 02:31      
                     RE: ALE---indicator...failed MPU      Stanley Lio      08/24/03 12:12      
                  RE: ALE---indicator...failed MPU      Kai Klaas      08/24/03 07:41      
                     RE: ALE---indicator...failed MPU      Stanley Lio      08/24/03 12:31      
                        RE: ALE---indicator...failed MPU      Raghunathan R      08/24/03 18:57      
                        Grounding scheme      Kai Klaas      08/25/03 22:29      
                           RE: Grounding scheme      Stanley Lio      08/26/03 09:43      
                           How to post pictures?      Stanley Lio      08/26/03 09:59      
                              RE: How to post pictures?      Kai Klaas      08/26/03 14:09      
                              RE: How to post pictures?      Ian Forse      08/27/03 13:22      
                                 RE: How to post pictures?      Raj Shetgar      08/28/03 23:55      
                                    RE: How to post pictures?      Stanley Lio      08/29/03 01:35      
   RE: ALE---indicator...failed MPU      Steve M. Taylor      08/24/03 18:35      
      RE: ALE---indicator...failed MPU      Stanley Lio      08/24/03 23:33      
         RE: ALE---indicator...failed MPU      Raghunathan R      08/25/03 01:56      
   RE: ALE---indicator...failed MPU      Stanley Lio      08/28/03 09:11      
      RE: ALE---indicator...failed MPU      Steve M. Taylor      08/28/03 10:51      
         RE: ALE---indicator...failed MPU      Stanley Lio      08/28/03 20:54      
      RE: ALE---indicator...failed MPU      Kai Klaas      08/28/03 14:07      
         RE: ALE---indicator...failed MPU      Hans Van Pelt      08/28/03 14:34      
            RE: ALE---indicator...failed MPU      Kai Klaas      08/28/03 19:16      
   RE: ALE---indicator...failed MPU      Stanley Lio      08/28/03 09:31      
   RE: ALE---indicator...failed MPU      Stanley Lio      08/29/03 07:33      
      RE: ALE---indicator...failed MPU      Kai Klaas      08/29/03 08:50      
         RE: ALE---indicator...failed MPU      Steve M. Taylor      08/29/03 09:07      
            RE: ALE---indicator...failed MPU      Kai Klaas      08/29/03 09:40      
               RE: ALE---indicator...failed MPU      Steve M. Taylor      08/29/03 10:35      
                  RE: ALE---indicator...failed MPU      Stanley Lio      08/29/03 13:49      
                     RE: ALE---indicator...failed MPU      Erik Malund      08/29/03 13:54      
                     RE: ALE---indicator...failed MPU      Steve M. Taylor      08/29/03 15:37      
      RE: ALE---indicator...failed MPU      Stanley Lio      08/29/03 13:52      
         RE: ALE---indicator...failed MPU      Raghunathan R      08/31/03 09:52      
            RE: ALE---indicator...failed MPU      Stanley Lio      08/31/03 10:28      
            RE: ALE---indicator...failed MPU      Stanley Lio      08/31/03 10:37      
               RE: ALE---indicator...failed MPU      Steve M. Taylor      08/31/03 10:41      
                  RE: ALE---indicator...failed MPU      Stanley Lio      09/01/03 08:13      

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