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- Newsgroups: sci.electronics
- Path: sparky!uunet!usc!zaphod.mps.ohio-state.edu!uwm.edu!csd4.csd.uwm.edu!pegasus
- From: pegasus@csd4.csd.uwm.edu (David R Hucke)
- Subject: 8051 help needed urgently!
- Message-ID: <1992Jul30.070338.6778@uwm.edu>
- Originator: pegasus@csd4.csd.uwm.edu
- Sender: news@uwm.edu (USENET News System)
- Organization: Computing Services Division, University of Wisconsin - Milwaukee
- Date: Thu, 30 Jul 1992 07:03:38 GMT
- Lines: 48
-
-
- Hi everybody!
-
- Well I finally got my 8051 compatible micro-controller in the mail
- and got it all wired with a crystal and MAX232 chip and reset hardware.
-
- I was able to invoke the onboard serial program load mode and load a
- program on the chip...
-
- The program simply set a bit on a port...
-
- I had an LED hooked up to port 1 pin 1 with a resistor and connected to
- ground like this:
-
- |
- | Port 1 Pin 1
- |
- LED
- |
- ^v^v^v 150 ohm resistor
- |
- |
- GND
-
- So my first program was this:
-
- setb P1.1 ;; Set Port 1 Pin 1 to 1
-
- This turned on the LED as expected...
-
- Now my second program was this:
-
- clr P1.1 ;; Set Port 1 Pin 1 to 0
-
- This should have turned off the LED.. It did not turn off the LED... In fact
- nothing I do turns the LED off...
-
- Anybody have any idea what is going wrong?
-
- When I go into Serial Load mode (RST goes low) the LED still on also.
-
- Any help would be appreciated...
-
-
- --
- pegasus@csd4.csd.uwm.edu David R. Hucke
- UW-Milwaukee Film Major
- --
-