Frequency Generator Microcontroller Source code.

[Loster]

[thrival]

Loster:

I downloaded your .rar file and had trouble making sense of the contents,
probably partly because I don't have your device to work with. Are you talking about a CLKGEN?

(http://www.altium.com/files/learninggui ... 0CLKGEN%20
Frequency%20Generator.pdf)

Being able to digitally bulls-eye the frequency of one's choice is a valuable thing. I noticed the above device only comes close, as the chosen frequency must be some divisor of the clock input. But, it also lists the actual frequency. I'm more interested in the latter feature as a cheap O-scope/read-out to set home-made oscillators. If it also reported the duty cycle, that would be great.

Please tell me where you found the plans and materials to throw one of these together. Thanks!

--thrival

[Loster]

Hey !

Ok well I got it from my head ..

Ok I've looked into your CLKGEN .. It's for FPGAs .. In fact, I made a Clock Generator from a FPGA too ... It could have a frequency between 0 hz and 100 mhz ... But it was configured in the source with no keypad or lcd .. so I have to rework it a bit to add those features .. The advantage of the FPGA is the speed and the precision !! I love FPGAs but they cost $$ and you need a development board, the software (they make you pay), and you need the socket etc etc ..

Microcontrollers are a bit simpler, they are easily programmable and the hardware doesn't cost much, you don't need a fancy PLCC socket etc. .

But the limitation of my FreqGenerator is that the frequency is between 1hz - 4000000 hz .. .

To assemble the source code, get AVRSTUDIO from atmel.com I think ..
The datasheet of the device I am talking about : AT90S8515 can be found on atmel.com .. It's a Microcontroller and it is reprogrammable to suit your needs ..

All you will need is a power supply (lm7805) some caps and a LCD / keypad .. You can find some examples for the power supply, but it's something so simple that by looking at the datasheet you will understand.

In the RAR open the .ASM files, the main is : FreqGenMain.asm

It's Assembler so you need to learn it if you don't know it .
In the Datasheet of the MCU the opcodes are explained ..

Ok, well this is maybe not as easy for everybody, you need to know some fundamental base, but if you are looking into electronics I think you can make it ...

You will need a programmer too, to shoot the Assembled .hex file to the MCU, look for PonyProg on google...

Oh I forgot, you will need a 4mhz or 8mhz crystal for the MCU !

[Loster]

http://www.tfs.net/~petek/atmel/

Take a look at this site, it's for the 2313 of atmel, not the 8515 but it's about the same thing, you will learn the mcu .

[thrival]

Hi Loster.

Well to confess, is all a bit over my head, and I was exposed to
micro-electronics thru a course in robotics. I guess some of us
need to be led by the hand or we never get there. Human minds
have different aptitudes and what's simple for one isn't necessarily
easy for another.

I've seen kits that go for $49 bucks, not the $20. USD you
spent.

http://www.invent-electronics.com/freq_Counter.htm

The nice things is you don't need to know much to slap it together,
but it's still a lot to pay when you can buy discount working meters
off of Ebay. And I didn't read anything about needing to program
it; (Very intimidating, even just to interface.)

My interest is 7.533 Mhz (where hydrogen atom resonates), need
a meter that can nab it very accurately, but not otherwise useless
for bench purposes.

[Loster]

Thrival :

Yeah I understand .. Well, but I'm sure if you were really motivated to learn it you could.. But I understand that not everybody wants to take the trouble to do that ..

And if you are looking for 7.x Mhz, I would suggest a FPGA, but if you want to make this simple .. You could use a 555 Timer.. But I'm not sure if 555 timers can go to this frequency ...

Many circuits on 555 timers can be found easily on the net ..

And, you could invest in a Professionnal Frequency generator too ... but it's costy .. .

All in all, if you want to trade Money for Time (- To learn -), go with the FPGA, else, you'll have to trade simplicity with money ...

[Loster]

By the way, the link you provided is a Frequency COUNTER not a Generator ... Don't buy this ... It's to find the frequency of a signal not to generate one ..

[thrival]

Loster:

For me, reading a frequency accurately is more important. A person can throw an oscillator together and play with frequency via adjustable pots and caps, but it's the counter lets me know where I'm at. How many signal generators are dead-nuts with their dials? Even the digital types can only come close because they use divisors of input clocks.

And the best accuracy comes with increased complexity.

Learning is fine, but people forget that their specialties are just that, and no one has unlimited time to study everything to the tenth power. It's a lot to ask of everyone, just to use water as fuel.

[Loster]

Thrival :

Ok I finally understand what you meant ..

Well I believe that the Digital type of oscillators are very accurate! ..
And your counter will have some inaccuracy too since it is digital and driven by a microcontroller ..

The microcontroller introduces overhead processing when Interrupting to calculate the pulses of the frequency .. It could make some readings a bit inaccurate, but I doubt it would be that inaccurate anyways . .

Yep, I know that it would be a lot for people to learn everything for dissociating water.. but in my opinion it is worth it !

I am speaking of my own opinion, but I like to learn everything I can .. it's like challenging myself everytime ! . .

Anyways. . Your idea to backup the oscillator frequency with a counter is good one .. But be sure to get a quality freq counter . ..