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David Prentice
01/02/12 03:35
Read: 502 times
Wormshill
England


 
#185247 - Your schematic is wrong
Responding to: ???'s previous message
Remove the transistor switch in the VCC line. Or turn it on permanently.
Copy the RESET circuitry from the data sheet. e.g. capacitor between RESET and VCC, resistor from RESET to GND.

Alternatively use a proper external RESET supervisor chip.
There are several ways of wiring an 8051 RESET. Copy an existing proven design.
I doubt that your schematic would work reliably.

The AVRISP-2 should program a AT89S52 just fine.

Connect all 6 ISP wires to the relevant AT89S52 pins.

The AVRISP-2 will use the active-high RESET. You should read signature successfully with ISP frequency of 200kHz or less.

David.

List of 32 messages in thread
TopicAuthorDate
AT89S52 and ISP problem      Adam Collins      01/01/12 13:38      
   Quick Schematic Obversation      Michael Karas      01/01/12 18:28      
      hmm      Adam Collins      01/01/12 22:20      
         Your Reset Input      Michael Karas      01/02/12 03:56      
            Thanks!!      Adam Collins      01/02/12 07:28      
   Your schematic is wrong      David Prentice      01/02/12 03:35      
   The AT89S52 needs a reset chip!      Kai Klaas      01/02/12 05:44      
      The AVRISP-2 is a USB device      David Prentice      01/02/12 06:02      
   what an AWFUL design      Erik Malund      01/02/12 07:35      
      Isn't mine!      Adam Collins      01/02/12 08:06      
         Compare several schematics      David Prentice      01/02/12 08:16      
            Thanks!!      Adam Collins      01/02/12 08:41      
               Sink or source? Does matter a lot!      Per Westermark      01/02/12 08:50      
                  Not granted      Adam Collins      01/02/12 09:07      
                     Processor can be used      Per Westermark      01/02/12 09:20      
                        Yeah..      Adam Collins      01/02/12 09:33      
                     cure for ignorance      Erik Malund      01/02/12 11:11      
         you forgot the quotes      Erik Malund      01/02/12 08:23      
         well      Erik Malund      01/02/12 08:30      
            Funny      Adam Collins      01/02/12 08:47      
               RC resets are evul      Per Westermark      01/02/12 08:57      
                  So?      Adam Collins      01/02/12 09:02      
                     Not necessarily,,,      Kai Klaas      01/02/12 09:18      
                     I guess you are a student / hobbyist      David Prentice      01/02/12 09:19      
                        Oh..      Adam Collins      01/02/12 09:30      
                        Even or better just then...      Kai Klaas      01/02/12 09:45      
                           Where to apply 100nF?      Adam Collins      01/02/12 10:01      
                              Shortest possible distance      Per Westermark      01/02/12 10:34      
                        especially not for a hobbyist      Erik Malund      01/02/12 11:23      
                  RC RESET worked fine for years ,,, but ...      Richard Erlacher      01/02/12 20:01      
               no, not "will" but "is likely to"      Erik Malund      01/02/12 11:17      
                  an added IMPORTANT comment      Erik Malund      01/02/12 11:26      

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