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homebrew programming of pic16f628

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New Member
I admit to posting this in another category
group, but here it is -

because of my background in programming and electronics
I am determined to send a line of random data to
program memory of the pic16f628 and then to READ it back confirming
that the prgrmng was successful

I am using qbasic lang sending sigs from the parallel port
of a pc laptop with homebrew hardware

I am utilizing 160 pgs of elect specs & 20 or more pgs
programming spec's found on the internet

I've noted some problems people have had with
more sophisticated programming software

so far I've changed my hardware (homebrew)

when I program my one line of random data into
pgm mem, I then try to read it back, mainly with an LED
option to look at data appearing at the DATA pin
when it is in output mode

so far no signs of life with my PIC

I have brought my mclr & pgm volt up to
5v (rather than just logic hi - say 3.5)

I am proceeding on the basis that there are no MAX
time constraints on the clock and data signals

when I raise mclr & pgm I am assuming
PC says zero as the loc for loading my data

in my read pgm when I raise mclr & pgm
I also assume I am at loc zero

I am also assuming that config says 1
for low volt pgming

are any of these assumptions faulty?

Larry Keegan in Stoneham, MA, USA



New Member
programmed the pic16F628

Joined: 09 Nov 2003
Total Posts: 3
Re: my own programming of the pic16f628
Posted: 12-01-2003 12:54 PM
to all concerned
I was successful in loading in some
random test data into my PIC16F628
at 10:30 PM EST on Saturday, Nov 29
and verifying the data
using my own software (QBASIC) and
hardware connected to the parallel port
of an older PC laptop. My earlier attempts
were uncsuccessful, since I was using the
low voltage mode of programming. When I
changed my hardware/software to use the high
voltage mode, I achieved success.
I also conclude that my PIC16F628 came
from the manufacturer with the CONFIGURATION
word set for permitting high voltage prgming only.
A great feeling! Now I will proceed to entering
a Hello World pgm in which I will hand assemble
the instructions. It will probably blink an LED
or turn an LED on when I close a switch to a
separate port assigned as input. Sound OK?
I seem to be having too much fun
at age 75.
Larry Keegan in Stoneham, MA


New Member
Good for you!

A blinking led program is the best way to start programming a PIC :)

Keep up the good work, even at that young age!

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