Hi,
I tried to set up a circuit with a AT89S52 8051 microprocessor on breadboard. I programmed the chip with an Arduino through in system programming. I used an external clock which I connected to XTAL1 pin and I left XTAL2 pin not connected.
Anyway, I was able to read the signature bytes, write bytes to memory and read them back for verification.
However, when I pull the reset LOW to begin normal operation, microprocessor works randomly. I was trying to blink an LED. I searched the web and tried everything. I connected ground side of the LED to port1.0 and I try to write 0 to port1 to turn LED on. But it doesn't work.
There shouldn't any problems with clock because if there were, ISP wouldn't have worked.
I am controlling the reset pin through a digital pin of Arduino and I give a reset pulse when I restart the device. Vcc is connected to 5V supply and similarly ground is connected to Gnd of Arduino.
I thought maybe the processor is damaged but then how is it possible to successfully program a damaged chip through isp. Maybe there is a problem with my breadboard setup.
I tried to set up a circuit with a AT89S52 8051 microprocessor on breadboard. I programmed the chip with an Arduino through in system programming. I used an external clock which I connected to XTAL1 pin and I left XTAL2 pin not connected.
Anyway, I was able to read the signature bytes, write bytes to memory and read them back for verification.
However, when I pull the reset LOW to begin normal operation, microprocessor works randomly. I was trying to blink an LED. I searched the web and tried everything. I connected ground side of the LED to port1.0 and I try to write 0 to port1 to turn LED on. But it doesn't work.
There shouldn't any problems with clock because if there were, ISP wouldn't have worked.
I am controlling the reset pin through a digital pin of Arduino and I give a reset pulse when I restart the device. Vcc is connected to 5V supply and similarly ground is connected to Gnd of Arduino.
I thought maybe the processor is damaged but then how is it possible to successfully program a damaged chip through isp. Maybe there is a problem with my breadboard setup.