alarm house 16f877 ?

[seti75]

thank Chippie


compilation is good ?
http://www.monsterup.com/upload/124776063671.jpg

 

[Chippie]

If you program the hex file into the 877, and wire up to the schema it should blink the led....

 

[seti75]

I do not know only c' is vpp, pgd, pgc I have just finished l' test without connected vpp, pgd, and pgc the led remains extinct, I believe that the 16f877 died!

 

[blueroomelectronics]

That's why it's handy to keep a spare.

 

[seti75]

test 16f877 flash led with another program

my 16f877 --->

YouTube - clig 16f877

I do not include/understand any more ! j" stays on my peak had died…

.it is ok ?

why it does not function with the lcd 2x16 ?

 

[blueroomelectronics]

Since the LED is flashing why would you assume the 16F877 is broken?

 

[be80be]

why it does not function with the lcd 2x16 ?

I told you when you first posted your osc is not working right . Your using a 20mzh crystal on the bread board that don't always work as planned. You posted a picture where it made a bunch of squares but no words I have had that happen it was the OSC not coming to speed change your code to use the 4mhz crystal and the lcd will work
on your 16f877

 

[seti75]

the 16f877 does not function with my lcd 2x16

to see the post at the beginning.

with the moin 10 programs tested, no n' functioned with the 16f877,

the lcd is good since it was tested with the 16f84 and it functions perfectly

be80be -->
but j' board makes test with the lcd and the 16f877 with quartz of 4mhz and without quartz I n' board ever have any favorable result

 

[be80be]

the 16f877 does not function with my lcd 2x16

to see the post at the beginning.

with the moin 10 programs tested, no n' functioned with the 16f877,

the lcd is good since it was tested with the 16f84 and it functions perfectly

Your using a 4 mhz crystal with the 16f84 Your using a 20 mhz crystal with the 16f877
When you tested the blink code what crystal did you use

 

[seti75]

4mhz flash led 16f877 ..... ..ok
4mhz lcd 16f84.................... ..ok
4mhz and 16f877 and lcd ....... not good
20mhz and 16f877 and lcd ......not good

 

[be80be]

This is how I do it. In this pic look at how the crystal resonator is placed **broken link removed**

They don't work good with jumper

 

[Chippie]

The original schematic used a 20Mhz xtal...

 

[be80be]

chippie I no what it used did you look at the picture that OP posted the 20mhz crystal is hooked to the 16f877 with jumpers. The chips not osculating is what's wrong
This is OP board look at osc **broken link removed**

 

[Chippie]

chippie I no what it used did you look at the picture that OP posted the 20mhz crystal is hooked to the 16f877 with jumpers. The chips not osculating is what's wrong

Ah..sorry didnt realise you knew about the xtal....but yeah agree his setup isnt v.good

Scoping the pins should tell whats going on...

 

[seti75]

Before opening the post (1) first one, I had made this alarm
At the beginning the problém was the same ! Nothing on the lcd.
It is for that that I post Voila the position of the quartz, and it was the Same thing

my alarm [url=https://img38.imageshack.us/i/quartz.jpg/]Imageshack - quartz[/URL]

 

[be80be]

It is for that that I post Voila the position of the quartz, and it was the Same thing

It's still the Osc not working I have had it happen. It's up to you to fix it.
I have changed crystals and it worked fine. If I could fly over I bet I'd have it running
in a sec.

 

[be80be]

The blinking a led with the Watchdog Timer on a 16f877 will not tell you if the crystal
is working

The Watchdog Timer is a free running on-chip RC oscillator
which does not require any external components.
This RC oscillator is separate from the RC oscillator of
the OSC1/CLKIN pin. That means that the WDT will
run, even if the clock on the OSC1/CLKIN and OSC2/
CLKOUT pins of the device has been stopped, for
example, by execution of a SLEEP instruction

 

[seti75]

be80be , thank
I thank all for your help .
I leave this project because it will never work! One friends think that the program b' is not good.
This program was on a French forum, but the one that he proposed it was not on his (her,its) program,
the electronique pratique (review) practical do not propose any more the program.

If you know an alarm with a lcd and the same possibility that that her(it) thank you for me proposed.
I leave , the program which made me lose a lot of time(weather), if a person want to make tries...

program ---> Free - Envoyez vos documents

Imageshack - sanstitre1txf

Imageshack - sanstitre3p

Imageshack - sanstitre4i
Imageshack - sanstitre5c

 

[blueroomelectronics]

Was this a school project?

 

[be80be]

Well seti75 it's up[ to you but I don't think your problem is as hard to fix as you think.
You can't test the oscillator with the code from blueroomelectronics He was using the wdt it would still blink if you pulled the crystal out and threw it away.I still say it's in that 20 mhz crystal your using