Re: Programming the pic16F84A


Jon Slaughter a écrit :

"lerameur" <lerameur@xxxxxxxxx> wrote in message
news:1157329739.868079.105890@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Hello,

I have been trying to build a programmer for the PIC16F84A microchip.
After a couple of design not working. Then I found this web site
(http://sciencezero.4hv.org/electronics/com84.htm) stating that a 13v
produced by the serial port is needed. From my voltMeter, I can only
record about 0.5v.
They say that newer computer do not have enough voltage at the serial
port.
Is this true ? If so How can I fix the problem.
I tested 4 circuits over and over again, they cant be all wrong..


You really should use an external power source. You can use a cheap DC
adaptor with a regulator. You will need both 13 and 5V's so you'll probably
want something like a 15-17V DC adaptor with a 13V and 5V regulator. Once
you got this you'll also need a tristate ic so you can control them and a
few transistors to interface the power with the pc. There are plenty of
schematics out there for it. The one your looking at is pretty basic and is
crap.

http://www.bobblick.com/techref/projects/picprog/f84pgmsc.gif

something like this should work... its very similar to what I did and I
didn't have a huge problem with it. (although I used a bench supply so I
didn't need the regulators). If your not using Winpic then you should pic
that up as its probably the best to use. It also has many default settings
for popular programmers. You gotta make sure that the controls from the pc
match what the pic see's. i.e., when the software turns on the main voltage
it actually comes on and doesn't go off or something like that... also that.

in win pic it lets you test the controls to so you can figure it all out
quite easily.

Theres tons of resources on the net and spending a little time with google
might make it much easier.

I finally got that crappy circuit to work with the power supply at 5
volt.
Eventually I would like to program bigger chip, I was inititially
thinking of doing this circuit:
http://feng3.cool.ne.jp/pgm5v2/sch528.gif
They use a ZIF socket to accomodate chips up to 40 pin.
But this circuit do not have a power supply.
I am gussing it did work for Feng...

ken

.

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