problem of loading program in P89V51RD2 due to float GND(PIN 5) of serial cable

Started by Tanumoy, July 25, 2013, 07:29:40 AM

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Tanumoy

Hello Sir/Madam
                         After reading some of the Post in the forum I found out using a multimeter that PIN 5 of serial cable has +10V with respect to pin 3 of serial cable so it may lead to a floating gnd problem in the ckt,and also the flash magic is unable to program the microcontroller its showing message box of reset option when i push start buttom but when i am pressing the reset buttom its not responding to it.
                                                Even I have a shock sensation felling when i touch the gnd terminal of the ckt(After joining the gnd of serial cable to the 5V Ckt GND)
                                                PLEASE help me to solve this problem.I am using a desktop PC.
                                                                                       Thanking You
                                                                                        Tanumoy                                               

Andy Ayre

You shouldn't be getting any electric shocks from any circuitry. It's possible you have damaged the microcontroller using static electricity or the improper ground.

Andy
Embedded Systems Academy, Inc.
support at esacademy dot com

Tanumoy

Hello Andy
                         Ya I have a improper ground in my room( i.e no earthing is done) .Can this be a reason that when flash magic is telling to reset the device but when i press reset button, flash magic is not responding to it.
                          Please tell me if this may be a reason then i should do a earthing in my room or the problem may be some thing else.
waiting for your reply
Thanking You
Tanumoy

Andy Ayre

I suggest you set up an anti-static workstation:

http://en.wikipedia.org/wiki/Antistatic_wrist_strap

http://en.wikipedia.org/wiki/Antistatic_mat

*After* you have done that discard your microcontroller as it is probably damaged, and get a brand new one from an authorized NXP distributor.
Embedded Systems Academy, Inc.
support at esacademy dot com