Digital Clock Frequency Generator In Place of Oscillator/Crystal/Resonator Stamp 1

microcontrolleruser

Will that work if you select square wave?

First one to use is 1 khz.

Will Stamp 1 run at 1 khz?

jmg

microcontrolleruser wrote: »

Will that work if you select square wave?

Sure, it is a Static CMOS process IC

microcontrolleruser wrote: »

Will Stamp 1 run at 1 khz?

Depends on what you expect 'run' to mean ?
Someone has Linux booting on a 8-bit AVR, so almost anything can 'run'

microcontrolleruser

'Sure, it is a Static CMOS process IC'

Don't have frequency generator in front of me yet.

Company that makes it will dig up manual for me after 3 day weekend.

'Depends on what you expect 'run' to mean'

Run in the usual sense.Execute code.

Okay to change delay loops etc.

Whit

@microcontrolleruser - Still looking for a Parallax BASIC Stamp Professional Development Board? See this thread - https://forums.parallax.com/discussion/160013/basic-stamp-professional-development-board

I got one, but there may be some leads here!

microcontrolleruser

Whit Thanks for the link.

'Still looking for a Parallax BASIC Stamp Professional Development Board?'

Yep! If anybody has one and is willing to part with it let me know.

Have Propeller one and would like to get a Stamp one too.

microcontrolleruser

It looks like a digital clock frequency generator is what we want to use.

Not an analog one.

Jury is still out about running a Stamp at 1 khz.

So we are getting a 1 Hertz to 100 khz clock generator.

Should have the little Stamp humming along!

jmg

microcontrolleruser wrote: »

It looks like a digital clock frequency generator is what we want to use.
Not an analog one.

yes.

microcontrolleruser wrote: »

Jury is still out about running a Stamp at 1 khz.
So we are getting a 1 Hertz to 100 khz clock generator.
Should have the little Stamp humming along!

No reason it should not work.

You could get a module like this one (just $1.10, bootloading )
http://www.electrodragon.com/product/n76e003-mini-development-board/
and use that as a Clock Generator, with a few lines of code.
Good to 16MHz.

Addit: Thought I'd seen a graph somewhere of trim Value/MHz, but that's proving elusive.
I did find N76E003 trim code, that gives a 9-bit oscillator trim step of 0.25%/LSB
If that is linear, that's more than ample to cover the +/- sqrt2 for a continual frequency trim, when combined with binary divider.

microcontrolleruser

Thank you for the link to generator.

Let me post the link to one we are looking at.

It's same kind of thing made by Elenco.

AwesomeCronk

I was introduced to the world of electronics by an Elenco Snap-Circuits kit.

microcontrolleruser

'I was introduced to the world of electronics by an Elenco Snap-Circuits kit.'

We use Elenco for what we can.Good stuff!

They go way back.

microcontrolleruser

Here's the link to generator.

https://www.elenco.com/product/1mhz-function-generator/

Here's link to manual.

https://www.elenco.com/wp-content/uploads/2017/10/FG-500K_REV-H-2.pdf

Can that signal be used as oscillator signal for Stamps and PIC's?

Mike Green

This is not a very good digital clock generator. It's called a function generator and it provides either a sine wave or triangle wave neither of which is really suitable for driving digital circuitry. For that you need a square wave with sharp on-off transitions. You can sometimes use a Zener diode clipper across the function generator to throw away the signal peaks since the initial portion of the sine wave usually has steep sides, enough to approximate a square wave. It's better to have a clock generator with a square wave output

microcontrolleruser

' It's better to have a clock generator with a square wave output '

Thanks Mike.

Is the oscillator/crystal/resonator signal like this generator or a good clock generator signal?

You know where I'm headed with this.

Do Stamp/PIC's and PIC's have circuitry in them to clean up a frequency generator signal?

Will post info on Elenco Clock Square Wave Generator.Just for backup.

Mike Green

There are different circuits for producing a clean square wave vs. a high quality sine wave and/or triangle wave. The PICs and most other devices that use a crystal or resonator for their clock source have a simple oscillator using two inverters (or the equivalent) in series to produce a nice square wave. Typically, there are a couple of more inverters in series to clean up the edges of the square wave and isolate the clock oscillator from the rest of the device. Look at the datasheet for the PICs and the discussion (and schematic) there on clock generation.

Most digital devices that require a clock source expect to find a reasonably clean square wave as the clock ... not a sine wave or triangle wave. These latter signals just don't change state quickly enough. Like I said, you can sometimes use a Zener diode clipper followed by a couple of inverters or flip-flops to clean up a sine wave, but it's best to just start with a digital clock signal.

jmg

Mike Green wrote: »

... but it's best to just start with a digital clock signal.

A device like a 74HC4060 can make a useful Clock generator, as it has many binary divided outputs, and an oscillator built in.
- or a small MCU, as mentioned above...

Mike Green

Thanks jmg. microcontrolleruser, the 74HC4060 datasheet is a good reference for a typical digital clock generator. It has an oscillator, followed by a couple of inverters to clean up the signal, followed by a bunch of flip-flops to divide the raw clock signal by powers of 2 with taps along the way. It's a great way to get a 1Hz or 2Hz digital clock for a timepiece.

microcontrolleruser

'have a simple oscillator using two inverters (or the equivalent) in series to produce a nice square wave'

'couple of more inverters in series to clean up the edges of the square wave and isolate the clock oscillator '

Thank you Mike.

Think we will fall back the external oscillator for the mean time.

Keep our eyes open for right instrument or parts.

Publison

Mike Green wrote: »

This is not a very good digital clock generator. It's called a function generator and it provides either a sine wave or triangle wave neither of which is really suitable for driving digital circuitry. For that you need a square wave with sharp on-off transitions. You can sometimes use a Zener diode clipper across the function generator to throw away the signal peaks since the initial portion of the sine wave usually has steep sides, enough to approximate a square wave. It's better to have a clock generator with a square wave output

Looks like the Square and Sawtooth waves come off of the yellow banana plugs. Hard to see in the picture above.

Publison

I would get a Flip module for 28 bucks, on sale.

https://www.parallax.com/product/32123

And use a simple Spin program from the OBEX to generate your clock.

http://obex.parallax.com/object/783

http://obex.parallax.com/object/688


It's only 3 volts, but may work with a simple transistor level shifter.

You don't have to build it and it has many other uses later.

microcontrolleruser

'Looks like the Square and Sawtooth waves come off of the yellow banana plugs'

Thanks Publison.

See the manual at the end.The manual is for building the generator too in first part.

In a nutshell it generates sine, triangle (sawtooth) and square waves.

This does not look like a logic generator.

Logic circuit is included on their Trainer boards.

Have to think long and hard about getting one of those.

Genetix

microcontroller,

Forrest Mims Engineer's Notebooks have a number of clock circuits.

microcontrolleruser

Thanks Genetix

Forrrest Mim's did the workbook for the Learning Lab.

I will check that out.

MIchael_Michalski

microcontrolleruser wrote: »

Will that work if you select square wave?

First one to use is 1 khz.

Will Stamp 1 run at 1 khz?

More like a leisurely walk.

MIchael_Michalski

Publison wrote: »

I would get a Flip module for 28 bucks, on sale.

https://www.parallax.com/product/32123

And use a simple Spin program from the OBEX to generate your clock.

http://obex.parallax.com/object/783

http://obex.parallax.com/object/688


It's only 3 volts, but may work with a simple transistor level shifter.

You don't have to build it and it has many other uses later.

Or a comparator with a open collector output.

microcontrolleruser

This points to building a timing circuit.

I would rather have it off the breadboard area.

Like a power supply where you only come in with the two wires 5v and ground.

The quick and dirty way is a crystal/oscillator/R-C circuit.

I think the square wave logic generators are maybe just that but with a variable element tossed in.