When I posted a response re: PIC vs AVR, I said my comparison would be
unfair because I compared a PIC 16F877A to an ATmega128.

So, right after I posted that reply I started a project with the
16F88. Not 10 minutes went by.

I needed a simple control system to animate an owl. Yup, an owl. I
bought one of the plastic owls that has a rotating, bobbing, head. I
added 6 yellow LEDs behind each eye and a servo to rotate the head. I
triggered the effect with a PIR sensor and had the controller tell an
MP3 player to play the owl sound track 3 times while the head moves
back and forth.

I didn't take more than an hour or so to get the controller up and
working. One reason is the ability of the 16F88 (and 16F87A, 16F876A
and 16F873A) to self program. Well, that and I have a lot of code
from other projects...

There is a Windows app called Screamer and a very small bootloader
call Bloader that can be loaded into the device with a standard
programmer. From then on, reprogramming is done of the serial port
and it is FAST! See


I had forgotten about that bootloader. I used it a few months ago on
a project I was doing for someone else.

So, cc5x, MPLAB and Screamer is all it takes to make a very nice
development platform.

Getting started early this year - Halloween is just around the corner!

Richard

On Thu, 27 Apr 2006 23:22:24 +0200, lcdpublishing <lcdpublishing@...> wrote:

Oh man, that sucks! Is there anyway to contact the seller and find

out from them or is it too late with the mods you did to it?

I'm afraid the seller would just say "piss off it was sold defective".

IMO there is a small difference between "defective" and "has been tinkered with already".

No i don't think i'll see any of that money again. But the thing is i still don't have a second proper sceen, which is worse.
Don't understand why they are so expensive, if i get unlucky a second time i can almost buy a new one!

Until now i had been lucky with defunct TFTs, one 15" and one 18" with minor problems still working fine.

Well, sometimes you get lucky, sometimes not...

ST

On Thu, 27 Apr 2006 19:19:37 +0200, Steve <polymorph@...> wrote:

He's back!


Where've you been?


Steve Greenfield

Maybe we can get the attachments sorted now?

ST

Oh man, that sucks! Is there anyway to contact the seller and find
out from them or is it too late with the mods you did to it?

You are also correct that in programming (as with video editing,
desktop publishing, etc. etc. etc.) you simply cannot have too big
of a monitor :-( Furthermore, the older you get the bigger the
monitor needs to be too!

Chris

Hi,

i just wasted 80eur on a broken TFT i can't repair.

When i got it and opened it i suspected bad things, the cable to

the

buttons was cut, and all the wires to the backlight CCFLs hat the

plugs

cut off. Also the fuse was missing and a few screws...

After i fixed the button cable and patched up some of the

backlight tubes

i got a picture - a very disappointing picture.

It shows clearly a spiderweb broken TFT, but the front glass is

flawless

and you can't see any break with the power off.

Now i'm very fed up with this, because there was a sticker on the

panel

front, mostly peeled off but you can see the remains. I bet my

arse it did

read "broken" before the seller ripped it off and sold it without

telling

what is wrong.

Oh well, not much to do about it i fear.

Any idea how a TFT can break "inside"? I would think this is the

back

glass broken, but how can this happen without the front glass

beeing

damaged?

I don't see how i could identify this before buying. Dead tfts are

so

incredibly expensive on ebay.
I really want a 18" one for the bench, the 15" one is ok for

reading the

odd schematic or datasheet, but recently i discovered for

programming it

is really not enough. And constantly moving about between the

bench and

the PC is quite a workout...

ST

Hi,

i just wasted 80eur on a broken TFT i can't repair.

When i got it and opened it i suspected bad things, the cable to the buttons was cut, and all the wires to the backlight CCFLs hat the plugs cut off. Also the fuse was missing and a few screws...

After i fixed the button cable and patched up some of the backlight tubes i got a picture - a very disappointing picture.

It shows clearly a spiderweb broken TFT, but the front glass is flawless and you can't see any break with the power off.

Now i'm very fed up with this, because there was a sticker on the panel front, mostly peeled off but you can see the remains. I bet my arse it did read "broken" before the seller ripped it off and sold it without telling what is wrong.

Oh well, not much to do about it i fear.

Any idea how a TFT can break "inside"? I would think this is the back glass broken, but how can this happen without the front glass beeing damaged?

I don't see how i could identify this before buying. Dead tfts are so incredibly expensive on ebay.
I really want a 18" one for the bench, the 15" one is ok for reading the odd schematic or datasheet, but recently i discovered for programming it is really not enough. And constantly moving about between the bench and the PC is quite a workout...

ST

On Thu, 27 Apr 2006 21:35:19 +0200, lcdpublishing <lcdpublishing@...> wrote:

You may want to give one of those brass-brillo pad things a try. I

have only used mine for one small project so far and I have a hunch

I won't be going back to a wet sponge. Won't know for sure till

after I use if for a while, but so far I am impressed.


Chris

I'm still not so sure about those, but i _will_ get one with my next order at one of the places which have them.

ST

We don't have those here.
Not even at post offices.

We have little rubber jars with a sponge in it.
One postman at the post office will have "sponge duty", wetting all sponges in the morning, each week a different person. That's how it is done here, usually, definitely no stamp moistener bottles.

ST

You may want to give one of those brass-brillo pad things a try. I
have only used mine for one small project so far and I have a hunch
I won't be going back to a wet sponge. Won't know for sure till
after I use if for a while, but so far I am impressed.

Chris





--- In Electronics_101@..., "Stefan Trethan"
<stefan_trethan@...> wrote:

How could one build something like that?

either a bottle with a hose attached leading into the sponge so i

only

need to press the bottle, or even something as crazy as a contacts

for

sensing moisture and that peristaltic pump i took out of the

broken

inkjet...

I already have a small bottle to drip distilled water onto the

sponge, but

i'm still annoyed if i find it dry...

It should not be permanently (like a wick leading into a water

container)

because i may not use the iron for days in a row and i don't want

the

thing to grow moldy.

Any ideas?

ST

On Thu, 27 Apr 2006 21:16:43 +0200, adicont2 <adicont2@...> wrote:

Bottle with a hose attached leading into the sponge is a good ideea,

but think about a "puf-puf" bottle, like those for liquid soap or

window cleaner.

This way, you simply push a button or press a lever to release a

precise quantity of water.

That's a fantastic idea!
"Now why haven't i thought of that?".

I have such bottles, and they are exactly what is needed!

Great suggestion - problem solved.

ST

:-)
You have a real passion for "automatic things" :-)

Bottle with a hose attached leading into the sponge is a good ideea,
but think about a "puf-puf" bottle, like those for liquid soap or
window cleaner.
This way, you simply push a button or press a lever to release a
precise quantity of water.



Adrian

--- In Electronics_101@..., "Stefan Trethan"
<stefan_trethan@...> wrote:

How could one build something like that?

either a bottle with a hose attached leading into the sponge so i

only

need to press the bottle, or even something as crazy as a contacts

for

sensing moisture and that peristaltic pump i took out of the broken
inkjet...

I already have a small bottle to drip distilled water onto the

sponge, but

i'm still annoyed if i find it dry...

It should not be permanently (like a wick leading into a water

container)

because i may not use the iron for days in a row and i don't want

the

thing to grow moldy.

Any ideas?

ST

:-)
You have a real passion for "automatic things" :-)

Bottle with a hose attached leading into the sponge is a good ideea,
but think about a "puf-puf" bottle, like those for liquid soap or
window cleaner.
This way, you simply push a button or press a lever to release a
precise quantity of water.



Adrian

--- In Electronics_101@..., "Stefan Trethan"
<stefan_trethan@...> wrote:

How could one build something like that?

either a bottle with a hose attached leading into the sponge so i

only

need to press the bottle, or even something as crazy as a contacts

for

sensing moisture and that peristaltic pump i took out of the broken
inkjet...

I already have a small bottle to drip distilled water onto the

sponge, but

i'm still annoyed if i find it dry...

It should not be permanently (like a wick leading into a water

container)

because i may not use the iron for days in a row and i don't want

the

thing to grow moldy.

Any ideas?

ST

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Use the old fashioned stamp moistener bottles.
Cant get much more low tech.

Gory Corey
csminion@...

????
????

Look for MinionsWeb at The Great Lakes Fright Fest June 2-4, 2006 ?, IronStock ?
The Midwest Haunters Convention??, and HorrorFind Weekend?

How could one build something like that?

either a bottle with a hose attached leading into the sponge so i only need to press the bottle, or even something as crazy as a contacts for sensing moisture and that peristaltic pump i took out of the broken inkjet...

I already have a small bottle to drip distilled water onto the sponge, but i'm still annoyed if i find it dry...

It should not be permanently (like a wick leading into a water container) because i may not use the iron for days in a row and i don't want the thing to grow moldy.

Any ideas?

ST

He's back!

Where've you been?

Steve Greenfield

--- In Electronics_101@..., "Sinister Dragon"
<Ptremewe@...> wrote:

Just started placing some of my vintage computer images at my Pbase

site.... Look out for some interesting images at:

Nothing really terribly exciting there yet, but lots to come.....

The Sinister Dragon

--- In Electronics_101@..., "lcdpublishing"
<lcdpublishing@...> wrote:

I know this has been covered before on an unrelated subject, but I am
trying to understand it better now.

Let's say I have one output on a micro (AVR) that is going to connect
to the inputs of 5 other micros. I know I should put a series
resistor between them - so one 1K resistor in series at the output pin.

Now at the inputs, I would pull the signals high with a 10K resistor.

The output signal is then connected to the Micro side of the pull up
resistor at the input pin (micros).

This works when going from one micro to another. However, when going
from one micro to more than one micro (inputs), I am puzzeled as to
what to do...

I could use one pull-up connected to all the input pins. This seems
to make the most sense.

But, for some reason I keep thinking I need a pullup on each of the
input pins.

I believe both would work fine, but one way has to be "Right" on way
has to be "Wrong".

Anyone care to clarify this situation for me?

Chris

I wouldn't think you would need a pull-up if you are driving the input
with a logic output. You would need it if you were using an open
collector circuit or a regular switch.

Thinking about this series resistor, it is really used to protect pins
from overcurrent. Whether the pin should be an input or output isn't
really the issue.

I would normally suggest a 330 ohm resistor to protect an output pin.
However, as you are driving 5 inputs and would like to protect them
from each other, the resistor value should probably be 1.5k at each
input pin. At this point I get dubious. I don't like high series
resistance but with CMOS there really won't be much voltage drop
across the resistor. I suppose even 10k would actually work.

If you find a circuit where you do need pull-up, you have to consider
where it is connected. If you did use 10k series resistance and 10k
pull-up at the pin, the lowest you could pull the pin would be 2.5V
(voltage divider) and that probably wouldn't work. If you installed
the pull-up at the outer end of the series resistor then you could
pull all the way to ground (assuming no current significant current
flow through the series resistor).

Richard


So, I would put a 330 ohm resistor in series with each of the 5 inputs
and connect them to the one output. This way you can't damage the
device with the output unless all

Chris,

One thing to keep in mind, if you have 1 micro connected to 5 and they all have a 10K pullup, the effective pullup is a 2K resistor.

My initial thought is that you could use a single resistor unless the distance is excessive. If it were me I'd try a single resistor, no greater than 4K7.

Cheers,

Peter.

lcdpublishing wrote:

--
------------------------------------------------------------------
Web: www.homanndesigns.com
email: homann@...
Phone: +61 421 601 665
www.homanndesigns.com/ModIO.html - Modbus Interface Unit
www.homanndesigns.com/DigiSpeedDeal.html - DC Spindle control
www.homanndesigns.com/TurboTaig.html - Taig Mill Upgrade board

I know this has been covered before on an unrelated subject, but I am
trying to understand it better now.

Let's say I have one output on a micro (AVR) that is going to connect
to the inputs of 5 other micros. I know I should put a series
resistor between them - so one 1K resistor in series at the output pin.

Now at the inputs, I would pull the signals high with a 10K resistor.

The output signal is then connected to the Micro side of the pull up
resistor at the input pin (micros).

This works when going from one micro to another. However, when going
from one micro to more than one micro (inputs), I am puzzeled as to
what to do...

I could use one pull-up connected to all the input pins. This seems
to make the most sense.

But, for some reason I keep thinking I need a pullup on each of the
input pins.

I believe both would work fine, but one way has to be "Right" on way
has to be "Wrong".

Anyone care to clarify this situation for me?

Chris

Yes, that "Thump" is very satisfying when everything is going "wrong"!




--- In Electronics_101@..., "Stefan Trethan"
<stefan_trethan@...> wrote:

I like those circuits.

Installed a large contactor that way on my bench to switch

everything on

or off. When i get fed up with something i can punch the off button

and it

shuts down with a satisfying thump ;-)

ST

Okay, will re-think my power-side E-Stop section. I believe I
understand what you are saying and it seems to coincide with what
actions I have used to power up big machines. Too bad I wasn't into
electronics when I worked for the machine builders, I could have
learned SO MUCH at that time :-(

Thanks Richard

Chris

There are standards. The normal Start-Stop circuit begins with a
normally closed Stop switch from one power rail to the junction of

a

normally open Start switch and one side of the holding contacts.

The

other side of the holding contacts connects to the other side of

the

Start switch (they are in parallel, the holding contacts hold the
Start state) and this junction connects to one side of the coil.

The

other side of the coil goes to common or ground. You really don't
want to switch an emergency circuit with a ground connection. Any
short circuit can simulate a ground connection.

The point is, it takes a specific action (pressing the Start

button)

to get power but even the loss of power will cause the Stop

function

to work. And the system won't restart.

A not particularly useful schematic is in Figure 7-16 here


Richard

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