brother_four
New Member
hey i'm new to PICs and i've been trying to program a pic for some time. heres the case :
I built a programmer for a 16f84a using the schematic given at oshonsoft.com and using the software given there. thing is i accidently connected MCLR to the node to which VDD should have been connected and vice versa. everything else was correct. now my pic got heated up as soon as i connected the supply and i took it off after some time. i later found my error and then made corrections.
now, everything works, i mean the voltages are correct, at all places , the LEDs light up and blink, my parallel port is fine and so is my wire and connectors but my chip is not being programmed. I found these anamolies :
1) when the programmer is not connected to a PC, Between pins 14 and 5 the voltage is NOT 5v but 4.15-4.3 v, usually the latter which is a diode drop less than i want. and .2v less than the minimum requirement of 4.5
2) Is it possible that my chip burnt out due to over heating or overvoltage ? because it was not previously programmed is it possible to find out if it is in working condition and how ? the max VDD is 5.5 V according to the datasheet and i had supplied it with a full 13 V.
I am using 2 9V batteries connected in series for supply. also i have tried to program it with ICProg as well using the Serial TAIT programmer which is very similar to the above.
pls help me out with this...
I built a programmer for a 16f84a using the schematic given at oshonsoft.com and using the software given there. thing is i accidently connected MCLR to the node to which VDD should have been connected and vice versa. everything else was correct. now my pic got heated up as soon as i connected the supply and i took it off after some time. i later found my error and then made corrections.
now, everything works, i mean the voltages are correct, at all places , the LEDs light up and blink, my parallel port is fine and so is my wire and connectors but my chip is not being programmed. I found these anamolies :
1) when the programmer is not connected to a PC, Between pins 14 and 5 the voltage is NOT 5v but 4.15-4.3 v, usually the latter which is a diode drop less than i want. and .2v less than the minimum requirement of 4.5
2) Is it possible that my chip burnt out due to over heating or overvoltage ? because it was not previously programmed is it possible to find out if it is in working condition and how ? the max VDD is 5.5 V according to the datasheet and i had supplied it with a full 13 V.
I am using 2 9V batteries connected in series for supply. also i have tried to program it with ICProg as well using the Serial TAIT programmer which is very similar to the above.
pls help me out with this...
