Chip with simple program for Toy

[Costas Vlachos]

"sine" <nomail@btinternet.com> wrote in message
news:biqm24$jci$1@hercules.btinternet.com...

I want to implement a watch application with the PIC16F676.
I don't need high resolution, counting seconds should be
enough i.e. it's not a stop-watch application. The questions are:
should I use timer0 or timer1 ; should I use the prescaler ;
since the interrupt occurs at roll-over i.e. from 255 to 0 (timer0)
or from 65535 to 0 (timer1), what do I need to do to get something
that is a factor of 1 second.
Tia.

Have a look here:

http://www.piclist.com/techref/microchip/time.htm

cheers,
Costas

 

[Don Klipstein]

In article <dr42lvkhjklhhhbl7834aip7uas8qfug90@4ax.com>, Rick wrote:

I am building a UV exposure box with six 8-watt tubes - 3 top, 3
bottom - double sided.

I was planning on wiring the tubes in series-pairs to save ballasts,
like so:

=======
L o---+-----^^^^^^^-------+ +-----+
| Ballast | | |
| (Inductor) +|-|+ |
| | - | |
| | | +-+
| Tube 1 | | |S| Glow Starter
| | | +-+
| | - | |
| +|-|+ |
| | | |
_|_ Power Factor | +-----+
___ Correction |
| Capacitor | +-----+
| | | |
| +|-|+ |
| | - | |
| | | +-+
| Tube 2 | | |S| Glow Starter
| | | +-+
| | - | |
| +|-|+ |
| | | |
N o---+-------------------+ +-----+

What I want to ask is if I am right that the ballast should be rated
at double the tube rating, i.e. a 16W ballast for two 8W tubes?

What value should the PFC capacitor be?

I would suggest using fewer, higher wattage tubes/lamps/bulbs such as 15
watt ones.
I do not expect two lamps in series to work at 120V with any simple
choke ballast. Details on the necessity of line voltage substantially
higher than the lamp arc voltage are in a web page of mine,
http://www.misty.com/~don/dschtech.html
Having two fluorescent lamps in series is not too uncommon in Europe
where the line voltage is 230V.

The wattage delivered by a ballast assumes a specific lamp arc voltage.

I do not consider the power factor capacitor necessary. Six 8-watters
uncorrected wil draw 1.5 amps or less.

More fluorescent lamp stuff is in Sam Goldwasser's Fluorescent Lamp
"FAQ", and I have a copy at http://www.misty.com/~don/f-lamp.html
There are other locations such as repairfaq.org.

- Don Klipstein (don@misty.com, http://www.misty.com/~don/index.html)

 

[Electromechy1]

hi,
here is the formula for working out your delay:

Timer initial value = 256 - delay cycles

delay cycles = (delay time * frequency/4)/2
= delay time * frequency/8

don't forget that each call /return adds 8 cycles. for larger times just
cascade registers. i have a delay routine which gives approx 1 sec delay email
me direct and i'll be happy to send it on.

best regards

shaun

 

[Rick]

On Sun, 31 Aug 2003 03:15:54 +0000 (UTC), don@manx.misty.com (Don
Klipstein) wrote:

In article <dr42lvkhjklhhhbl7834aip7uas8qfug90@4ax.com>, Rick wrote:
I am building a UV exposure box with six 8-watt tubes - 3 top, 3
bottom - double sided.

I was planning on wiring the tubes in series-pairs to save ballasts,
like so:

=======
L o---+-----^^^^^^^-------+ +-----+
| Ballast | | |
| (Inductor) +|-|+ |
| | - | |
| | | +-+
| Tube 1 | | |S| Glow Starter
| | | +-+
| | - | |
| +|-|+ |
| | | |
_|_ Power Factor | +-----+
___ Correction |
| Capacitor | +-----+
| | | |
| +|-|+ |
| | - | |
| | | +-+
| Tube 2 | | |S| Glow Starter
| | | +-+
| | - | |
| +|-|+ |
| | | |
N o---+-------------------+ +-----+

What I want to ask is if I am right that the ballast should be rated
at double the tube rating, i.e. a 16W ballast for two 8W tubes?

What value should the PFC capacitor be?

I would suggest using fewer, higher wattage tubes/lamps/bulbs such as 15
watt ones.
I do not expect two lamps in series to work at 120V with any simple
choke ballast. Details on the necessity of line voltage substantially
higher than the lamp arc voltage are in a web page of mine,
http://www.misty.com/~don/dschtech.html
Having two fluorescent lamps in series is not too uncommon in Europe
where the line voltage is 230V.

The wattage delivered by a ballast assumes a specific lamp arc voltage.

I do not consider the power factor capacitor necessary. Six 8-watters
uncorrected wil draw 1.5 amps or less.

More fluorescent lamp stuff is in Sam Goldwasser's Fluorescent Lamp
"FAQ", and I have a copy at http://www.misty.com/~don/f-lamp.html
There are other locations such as repairfaq.org.

- Don Klipstein (don@misty.com, http://www.misty.com/~don/index.html)

Thanks for the reply. I should have said that I am in the UK, so the
mains voltage isn't a problem. I got my diagram and information from
the f-lamp page you cited!

I wanted to use the 8W tubes because they are about the right length
for the biggest board I can imagine making. The more powerful tubes
are longer, so the extra light would just be wasted. I am aiming for
an exposure area of about 10x8 inches.

Do you know if I am right to double the ballast rating?

Rick.

 

[Winfield Hill]

TheElectron707 wrote...

i have a temperature controlled switch (bought it from market),
it is working with a THERMISTOR as a sensing device. i want to
see what are the specifications of that THERMISTOR, there is
no written thing on the thermistor like capacitors. just three
colored dots. do the dots indicate anything?

NTC thermistors have a temperature coefficient, called alpha,
a, which is about -3.9%/C, or -4%/C, etc. A main specification
for a thermistor is its resistance R_To at 25 degrees C. You
can use an ohmeter with your thermistor and calculate R_To using

| a T (1 - T/To)
| R_To = R_T e

where T is the temperature when you take the measurement R_T.
These temperatures are in degrees Kelvin = 273.15 + deg C, and
don't forget that alpha is negative, e.g. a = -0.04, etc. For
example, if you measure your thermistor at 20C, you can calculate
that its specified resistance at 25C will be 11% lower (try this
to check your math). You can use this value to find replacement
parts, do standard calculations for your thermistor, etc.

Thermometrics has a good theory reference on the web,
http://www.thermometrics.com/assets/images/ntcnotes.pdf

Thanks,
- Win

 

[sine]

"Robert Monsen" <postmaster@BulkingPro.com> wrote in message news:eig4b.236528$It4.112645@rwcrnsc51.ops.asp.att.net...

"sine" <nomail@btinternet.com> wrote in message
news:biqm24$jci$1@hercules.btinternet.com...
I want to implement a watch application with the PIC16F676.
I don't need high resolution, counting seconds should be
enough i.e. it's not a stop-watch application. The questions are:
should I use timer0 or timer1 ; should I use the prescaler ;
since the interrupt occurs at roll-over i.e. from 255 to 0 (timer0)
or from 65535 to 0 (timer1), what do I need to do to get something
that is a factor of 1 second.
Tia.



Here is a macro that pauses for a number of microseconds, using a 0
prescaler for
timer 1. If you call it in a loop 20 times, you'll get a second delay, plus
the
loop overhead.

So:

a set 0 ; used to generate labels for the PAUSE macro

PAUSE MACRO t
bcf T1CON,TMR1ON ; turn off timer1
movlw ((.65536 - (t)) & 0xFF) ; set it up so there are t ticks left till
rollover
movwf TMR1L
movlw (((.65536 - (t)) >> 8) & 0xFF)
movwf TMR1H
bsf T1CON,TMR1ON ; turn it on
bcf PIR1,TMR1IF ; clear the interrupt flag
M_again#v(a):
btfss PIR1,TMR1IF ; wait till timer rolls over
goto M_again#v(a)
a += 1
ENDM


delay_a_second:
movlw 20
movf loop_index
again:
PAUSE .49997
decfsz loop_index,f
goto again
return

I need the delay to be handled by the ISR, so I will have to write
is like this:
isr:
incf sec ; count from 0 to 255 for now
bcf T1CON,TMR1ON ; turn off timer1
movlw delaylo ; set it up so there are t ticks left till rollover
movwf TMR1L
movlw delayhi ;
bsf T1CON,TMR1ON ; turn it on
bcf PIR1,TMR1IF ; clear the interrupt flag
retfie

The question is what is the overhead here which needs to be added
to the delay to get an accurate time.

value of timer when we turn it off + 5 + delay

Does that look about right ? I'm not sure if we are supposed to count
the instruction that turns the counter off and/or the one which turns it on ?

 

[Winfield Hill]

Winfield Hill wrote...

TheElectron707 wrote...

i have a temperature controlled switch (bought it from market),
it is working with a THERMISTOR as a sensing device. i want to
see what are the specifications of that THERMISTOR, there is
no written thing on the thermistor like capacitors. just three
colored dots. do the dots indicate anything?

NTC thermistors have a temperature coefficient, called alpha,
a, which is about -3.9%/C, or -4%/C, etc. A main specification
for a thermistor is its resistance R_To at 25 degrees C. You
can use an ohmeter with your thermistor and calculate R_To using

| a T (1 - T/To)
| R_To = R_T e

where T is the temperature when you take the measurement R_T.
These temperatures are in degrees Kelvin = 273.15 + deg C, and
don't forget that alpha is negative, e.g. a = -0.04, etc. For
example, if you measure your thermistor at 20C, you can calculate
that its specified resistance at 25C will be 11% lower (try this
to check your math). You can use this value to find replacement
parts, do standard calculations for your thermistor, etc.

Thermometrics has a good theory reference on the web,
http://www.thermometrics.com/assets/images/ntcnotes.pdf

Oops, I followed my own advice to check my math and realized the
above -11% was for 22C, not 20C, where you should get -17.8% ...
So sorry! :&gt

Thanks,
- Win

 

[Abdul Ahad]

"Sir Charles W. Shults III" <aichipREM@OVEcfl.THISrr.com> wrote in message news:<69Y3b.991$WX5.72753@twister.tampabay.rr.com>...

I experimented with this one winter and came up with a simple solution.
Get some black plastic hose or tubing like they use for irrigation systems.
Coil it loosely and make a flat light collector that can get sun exposure during
the day. Also get a couple of those plastic buckets that hold about five
gallons and cover them in insulation. Spray foam is fine and painting them
black on the sunward side won't hurt.
Plumb the tubing to circulate to the buckets. They act as a heat mass.
During the day, the sunlight is gathered as heat and stored in the water in the
buckets. A small solar panel can run a pump that slowly circulates the water
when the sun shines. During the night, the extra few degrees will make a world
of difference, even without the pump running.
Oh, and when it gets dark, it should open a valve that lets the water out of
the pipe so it will not freeze in them.

Cheers!

Chip Shults
My robotics, space and CGI web page - http://home.cfl.rr.com/aichip

Thanks for your advice, I will consider it on time/effort vs return.
I like your web articles on space applications and robotics. I am
very much of an enthusiast - you could probably tell from the topics
in my website!

I really wanted to expand my "technologies that enable space
exploration" theme of interests, so that I can develop autonomous
ground vehicles that can explore rough terrain, avoid obstacles, send
back telemetry, utilise solar power, etc etc. I want to invest in
simple low cost, easily available technology hardware/software and was
considering the 'PIC Microcontroller' as a core chip as the answer to
all my applications requirements.

I know absolutely nothing about a PIC and don't know if it will
provide me with repeatable applications solutions, as I also plan to
use it to control a range of space research technology processes in
addition to ground vehicles. Examples include: remote "robotic
outposts" that can maintain heat/light levels for plant growth
experiments, control of thrust vector control for active stabilisation
of small rockets with thrusters, gimballs and gyros, timed operation
of remote sensing platforms launched on a small balloon, etc...

Before I invest a huge amount of time and effort in learning the PIC
Micro, I was hoping to get some opinions as to wether it would be
worthwhile? What power does the PIC require (e.g. 6v or 12v batery?,
is it a compact device in terms of size/weight? Can I use BASIC to
program it? What vesrion of the PIC series is best to start on? What
industrial apllications are PIC controlled? Will my software
programming skills on a PIC be useable for a hypothetical career in
industry or will it be only a waste of time if I choose to stop my
"space technology" pursuits?

Sorry, didn't mean to go on... hope you can help if not, can you point
me in the right direction please?
Much obliged
AA
http://uk.geocities.com/aa_spaceagent

 

[Sir Charles W. Shults III]

Hi, Abdul.

I really wanted to expand my "technologies that enable space
exploration" theme of interests, so that I can develop autonomous
ground vehicles that can explore rough terrain, avoid obstacles, send
back telemetry, utilise solar power, etc etc. I want to invest in
simple low cost, easily available technology hardware/software and was
considering the 'PIC Microcontroller' as a core chip as the answer to
all my applications requirements.

The PIC is a great tool for simplifying many thorny problems and packing the
results into a tiny space. But for most serious robotics, you will want to
consider a more proactical (and powerful) device. My favorite is the Jackrabbit
BL1800. You get 40 channels of I/O along with four serial ports and analog
functions. It is about the size of a credit card and is very easy to program in
C.
The PIC is best for small, simple things, but it can be used in some fairly
sophisticated devices. In robotics, I would recommend it as a local controller
for a specific function or device, like the "brains" in a leg, being controlled
by another, "higher order" processor. PICs are cheap enough and small enough tp
dedicate one to each limb if need be, distributing the processor load to many
points and also lending some redundancy to the design. This makes it harder to
kill.

I know absolutely nothing about a PIC and don't know if it will
provide me with repeatable applications solutions, as I also plan to
use it to control a range of space research technology processes in
addition to ground vehicles. Examples include: remote "robotic
outposts" that can maintain heat/light levels for plant growth
experiments, control of thrust vector control for active stabilisation
of small rockets with thrusters, gimballs and gyros, timed operation
of remote sensing platforms launched on a small balloon, etc...

All fun projects. You can easily get many of them running with PIC chips,
but in many cases where you have very fast realtime feedback, it may be beyond
the capabilities of the device. This will depend on two things- how many
inputs/outputs does your task need, and what sort of sensors are you using?
Lots of sensory processing will slow things down to a crawl in short order.
Just be aware that PIC stands for Peripheral Interface Controller, if I am
not mistaken. This means that it will have some limitations anyway, like the
lack of complex math functions built into the hardware. What it is very good
at, is handling hardware devices and bringing small projects to life.

Before I invest a huge amount of time and effort in learning the PIC
Micro, I was hoping to get some opinions as to wether it would be
worthwhile?

Yes, it is worthwhile. You will think of thousands of things to do with
PICs once you make your first PIC based project.

What power does the PIC require (e.g. 6v or 12v batery?,
is it a compact device in terms of size/weight?

There are CMOS versions that are very power-miserly. Older PIC chips run
anywhere from 2 to 6 VDC, and I suspect that there are newer ones that will run
lower. As for higher voltages, just use a voltage regulator to step down the
power supply. Compact? Sure. They are available as surface mount devices, all
sizes.

Can I use BASIC to
program it?

Yes, there are BASIC programming packages for PICs.

What vesrion of the PIC series is best to start on?

That will strongly depend on what you like to do or what your goal is. I
started with the old style PIC16C84 chip, then moved to the F84, the '54, and
others. But I moved to other processor platforms due to a need for more serious
processing power and speed. Still, I've worked with just about every
microprocessor at some time or another, starting all the way back with the 8008.
It's good to know a few of them, and you will soon derive the "flavor" of the
game from that.
All micros have many elements in common, and learning one of them will teach
you a lot about the rest.

What industrial apllications are PIC controlled?

Many automated chemical processes, measurement devices, or alarm systems
have PIC processors.

Will my software programming skills on a PIC be useable for a hypothetical
career in
industry or will it be only a waste of time if I choose to stop my "space
technology" pursuits?

You never waste a skill. The things you learn programming PICs can be
generally used in any microprocessor based programming environment.

Sorry, didn't mean to go on... hope you can help if not, can you point
me in the right direction please?

No problem- a Google search for PIC will turn up more information that you
will ever be able to read through.

Cheers!

Chip Shults
My robotics, space and CGI web page - http://home.cfl.rr.com/aichip

 

[Rick]

Never mind, I found the answer - I was right.

 

[Abdul Ahad]

"Sir Charles W. Shults III" <aichipREM@OVEcfl.THISrr.com> wrote in message news:<1Ws4b.7824$yi3.301239@twister.tampabay.rr.com>...

Hi, Abdul.

I really wanted to expand my "technologies that enable space
exploration" theme of interests, so that I can develop autonomous
ground vehicles that can explore rough terrain, avoid obstacles, send
back telemetry, utilise solar power, etc etc. I want to invest in
simple low cost, easily available technology hardware/software and was
considering the 'PIC Microcontroller' as a core chip as the answer to
all my applications requirements.

The PIC is a great tool for simplifying many thorny problems and packing the
results into a tiny space. But for most serious robotics, you will want to
consider a more proactical (and powerful) device. My favorite is the Jackrabbit
BL1800. You get 40 channels of I/O along with four serial ports and analog
functions. It is about the size of a credit card and is very easy to program in
C.
The PIC is best for small, simple things, but it can be used in some fairly
sophisticated devices. In robotics, I would recommend it as a local controller
for a specific function or device, like the "brains" in a leg, being controlled
by another, "higher order" processor. PICs are cheap enough and small enough tp
dedicate one to each limb if need be, distributing the processor load to many
points and also lending some redundancy to the design. This makes it harder to
kill.

I know absolutely nothing about a PIC and don't know if it will
provide me with repeatable applications solutions, as I also plan to
use it to control a range of space research technology processes in
addition to ground vehicles. Examples include: remote "robotic
outposts" that can maintain heat/light levels for plant growth
experiments, control of thrust vector control for active stabilisation
of small rockets with thrusters, gimballs and gyros, timed operation
of remote sensing platforms launched on a small balloon, etc...

All fun projects. You can easily get many of them running with PIC chips,
but in many cases where you have very fast realtime feedback, it may be beyond
the capabilities of the device. This will depend on two things- how many
inputs/outputs does your task need, and what sort of sensors are you using?
Lots of sensory processing will slow things down to a crawl in short order.
Just be aware that PIC stands for Peripheral Interface Controller, if I am
not mistaken. This means that it will have some limitations anyway, like the
lack of complex math functions built into the hardware. What it is very good
at, is handling hardware devices and bringing small projects to life.

Before I invest a huge amount of time and effort in learning the PIC
Micro, I was hoping to get some opinions as to wether it would be
worthwhile?

Yes, it is worthwhile. You will think of thousands of things to do with
PICs once you make your first PIC based project.

What power does the PIC require (e.g. 6v or 12v batery?,
is it a compact device in terms of size/weight?

There are CMOS versions that are very power-miserly. Older PIC chips run
anywhere from 2 to 6 VDC, and I suspect that there are newer ones that will run
lower. As for higher voltages, just use a voltage regulator to step down the
power supply. Compact? Sure. They are available as surface mount devices, all
sizes.

Can I use BASIC to
program it?

Yes, there are BASIC programming packages for PICs.

What vesrion of the PIC series is best to start on?

That will strongly depend on what you like to do or what your goal is. I
started with the old style PIC16C84 chip, then moved to the F84, the '54, and
others. But I moved to other processor platforms due to a need for more serious
processing power and speed. Still, I've worked with just about every
microprocessor at some time or another, starting all the way back with the 8008.
It's good to know a few of them, and you will soon derive the "flavor" of the
game from that.
All micros have many elements in common, and learning one of them will teach
you a lot about the rest.

What industrial apllications are PIC controlled?

Many automated chemical processes, measurement devices, or alarm systems
have PIC processors.

Will my software programming skills on a PIC be useable for a hypothetical
career in
industry or will it be only a waste of time if I choose to stop my "space
technology" pursuits?

You never waste a skill. The things you learn programming PICs can be
generally used in any microprocessor based programming environment.

Sorry, didn't mean to go on... hope you can help if not, can you point
me in the right direction please?

No problem- a Google search for PIC will turn up more information that you
will ever be able to read through.

Cheers!

Chip Shults
My robotics, space and CGI web page - http://home.cfl.rr.com/aichip

Hi Chip,
Many thanks for your info and detailed answers, sincerely appreciated!

I am encouraged to pursue PIC technology, just need the time and
energy to start on the long, steep learning curve (juggling my very
WIDE interests with a full time job!)

Cheers again,
Abdul Ahad
http://uk.geocities.com/aa_spaceagent/

 

[cirip cipcirip]

Petter,

Not really sure what a quadropole is, but if you meant a circuit with
multiple in/outs, this is known as multiport.

Multiports are being described by their S parameters. S parameters are
elements in the S (scattering) matrix. Impedance is characterized by Sii,
where "i" is the index of the port number which impedance you want to know.
If you want for instance to find out the impedance of port 2, you want to
take a look at S22. S22 is not the actual impedance, rather it is the
reflexion coefficient of that particular port when stimulated with a
generator having the internal impedance equal to the characteristic
impedance of the system, usually 50 ohm. Once you know the reflection
coefficient and the characteristic impedance it is not difficult to
calculate the input impedance.

There is no such thing as "basic equation". It depends on what is inside the
multiport. There are some basic eq. for cascading, paralleling and so on for
multiports, though.

You may want to take a look in a microwave text book.

Hope it helps,
Cirip





"Petter Norli" <pnorli@hotmail.com> wrote in message
news:1b919c75.0309010031.1d9ccd65@posting.google.com...

What are the basic equations describing the qudropole circuit in terms
of the impedance?

 

[John Popelish]

jj3000 wrote:

I need want to use 12-14V (vehicle power) to light up 6 LED together,
can someone tell me how to arrange such a circuit?

LED is about 1.5V IIRC. Can I just connect them up in series and
maybe add a extra resistor if needed?

That is the normal method, and the resistor is needed. If you use
enough LEDs to just use up the available voltage, the current is very
unstable, and very slight changes in voltage will produce large and
possibly damaging current changes.

Red LEDs drop less than 2 volts, green ones about 2.5 and blue ones
drop 3 to 3.5 volts. It is a good idea to have the LEDs drop about
3/4 of the available voltage, and calculate the resistor that allows
the desired current through while using up the rest. If your LEDs
really do drop 1.5 volts each at the current you wish to operate them
at (say, 10 mA) then 6 would drop 9 volts, and a 470 ohm resistor
would drop 5 volts while letting just over 10 mA to pass through the
whole string. For steadier light and more over voltage protection,
you might connect two sets of 3 in series with 750 to 1000 ohm
resistors.

--
John Popelish

 

[Baphomet]

No maybe about it. You will need a series resistor to prevent the l.e.d.'s
from drawing excessive current and burning out. Let's say for arguements
sake that you want the lights to draw 10 ma. The value of the resistor would
be (13 - (6 x 1.5)) / (.01) or approximately 390 ohms / 1/4 watt.


"jj3000" <jeremy_ho@my-deja.com> wrote in message
news:3ed9e158.0309021221.100fcecc@posting.google.com...

I need want to use 12-14V (vehicle power) to light up 6 LED together,
can someone tell me how to arrange such a circuit?

LED is about 1.5V IIRC. Can I just connect them up in series and
maybe add a extra resistor if needed?

 

[ron]

In the Dutch "Elektuur" of July/August this year at page 72 there is a
circuit with the LT1615 doing about the same as what you want to do, only
with white LED's and a supply of 2,5V to 4,5V. This seems to be a more
rational approach than just adding an extra resistor. Maybe one of the
experts can propose something similar for your situation???

--
Ronald Werner
Norway

 

[jj3000]

Thanks for your tips, it doesn't matter if I put resistor on the
ground or positive side, right?

I think I want to do 2 sets of 3 then, because I want to use the clear
type extra bright red LEDs, I doubnt they are 1.5V, and if I hook up
all 6 in series and they exceed 14V requirement, I won't even need a
resistor right?

What about a fuse, where should I put it, ground or negative side
matter? and how many amps fuse would I use?


John Popelish <jpopelish@rica.net> wrote in message news:<3F551C94.82843E43@rica.net>...

jj3000 wrote:

I need want to use 12-14V (vehicle power) to light up 6 LED together,
can someone tell me how to arrange such a circuit?

LED is about 1.5V IIRC. Can I just connect them up in series and
maybe add a extra resistor if needed?

That is the normal method, and the resistor is needed. If you use
enough LEDs to just use up the available voltage, the current is very
unstable, and very slight changes in voltage will produce large and
possibly damaging current changes.

Red LEDs drop less than 2 volts, green ones about 2.5 and blue ones
drop 3 to 3.5 volts. It is a good idea to have the LEDs drop about
3/4 of the available voltage, and calculate the resistor that allows
the desired current through while using up the rest. If your LEDs
really do drop 1.5 volts each at the current you wish to operate them
at (say, 10 mA) then 6 would drop 9 volts, and a 470 ohm resistor
would drop 5 volts while letting just over 10 mA to pass through the
whole string. For steadier light and more over voltage protection,
you might connect two sets of 3 in series with 750 to 1000 ohm
resistors.

 

[Bob Masta]

On Thu, 04 Sep 2003 06:01:40 GMT, Ryan Kremser
<news@rkremser.endjunk.com> wrote:

any recommendations for a computer based oscilloscope through the sound
card?

If you have an older system that can run real-mode DOS
(Win9x or earlier), and you have an ISA-bus Sound Blaster
or ESS card, you might want to have a look at my Daqarta
package. You can even build your own "card" from a
handful of resistors hung on the printer port, if you don't
have one of the above cards. It will be only 8 bits, same as
many digitial scopes, but unlike the sound cards will go
down to DC. See the LPTX driver info on the site.

The Windows version of Daqarta is in the works.


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
Shareware from Interstellar Research
www.daqarta.com

 

[The Butcher]

"ron" <microxls@tiscali.no> schreef in bericht
news:qNh5b.64209$Kb2.2898064@news010.worldonline.dk...

In the Dutch "Elektuur" of July/August this year at page 72 there is a
circuit with the LT1615 doing about the same as what you want to do, only
with white LED's and a supply of 2,5V to 4,5V. This seems to be a more
rational approach than just adding an extra resistor. Maybe one of the
experts can propose something similar for your situation???

--
There is nothing wrong with the easy method resistor-led when the voltage is

not too high or too low.
The LT1615 is a good solution when its powered from 3.6V cells. (But the
lt1615 is difficult to get in a store)

Grtz The Butcher
You need info about infrared remote protocols, 1 link:
http://users.pandora.be/davshomepage
!!! Remove f*ckspam in email address .

 

[Dr. Anton Squeegee]

In article <a7cde7357414ab7e63f0a77a7229df60@news.teranews.com>, Ryan
Kremser says...

any recommendations for a computer based oscilloscope through the sound
card?

Yes. Don't waste your time and money.

If you're serious about getting accurate measurements, and making
an investment in a piece of test gear that will serve you quite well in
times to come, poke around for a Tektronix 7000 series mainframe and
some plug-ins. For audio and low-RF work, I would suggest the Tek 7603,
the 7B53A timebase, and the 7A26 dual-channel vertical plug-in.

Altogether, I'd be surprised if the lot ran you over $100. Good
sources for such include ham radio swap meets, surplus test equipment
dealers, and Ebay.

Good hunting.

--
Dr. Anton Squeegee, Director, Dutch Surrealist Plumbing Institute
(Known to some as Bruce Lane, KC7GR)
kyrrin a/t bluefeathertech d-o=t c&o&m
"Quando Omni Flunkus Moritati" (Red Green)

 

[John Damm Sřrensen]

sunny wrote:

I want to change an program which is on the website here
http://www.piclist.com/techref/piclist/cheapic/alpha4m.asm
to work with the 16F676. First, I don't understand how
the pc side of it works, how exactly do we send a character
to the com port, i.e. what software do I need (especially
for windows 2000 professional)?
Tia


Sunny,

On the PC side you will need a terminal emulator like Hyper Terminal. I
believe its part of Windows. At least Win98 has it.
/John


Remove - nospam and nomail. to email me directly