Author Topic: A few hundred dollars: which function generator should I buy?  (Read 11211 times)

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Offline king.oslo

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A few hundred dollars: which function generator should I buy?
« on: September 25, 2011, 01:48:02 am »
The subject describes the question ;)

Thanks.M
« Last Edit: September 25, 2011, 12:15:49 pm by king.oslo »
 

Offline PeterG

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Re: A few hundred dollars: which function generator should I buy?
« Reply #1 on: September 25, 2011, 02:07:43 am »
How much is a 'Few Hundred'?
Have you thought about what your requirements are?

Let us know and we will be able to help you....

Regards
Testing one two three...
 

Offline Lawsen

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Re: A few hundred dollars: which function generator should I buy?
« Reply #2 on: September 25, 2011, 06:02:58 am »
This is a very vague question.  I am not going to do your homework about this topic.  A signal or function generator can costs between $60.00 pocket three functions waveform generator to $3000.00 USD with a large display screen showing the wave form as an arbitrary waveform generator.  What sort of wave form are you trying to model?  What is your frequency range and what type of signals are you working in?  I am happy with the $60.00 pocket three functions waveform generator to test amplifier circuits and other interests.  You could make your own waveform function generator with TTL logic and oscillator, too.  These are questions for you to answer for yourself.  Atten has a nice signal generator, but it is still expensive.  You need to study waveforms and decide for yourself.
 

Offline king.oslo

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Re: A few hundred dollars: which function generator should I buy?
« Reply #3 on: September 25, 2011, 12:14:56 pm »
Hey,

I agree with you three.

By the way Erik, jeg er fra Oslo ;) M
 

alm

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Re: A few hundred dollars: which function generator should I buy?
« Reply #4 on: September 25, 2011, 03:09:27 pm »
Do you think that it's appropriate to post in another language than English on an international forum? Other people might also be interested in this thread, either now or in the future. Forums aren't just helpdesks to answer somebody's question. They also serve as a searchable collective knowledge base. What would the value of this forum be if most of the threads were in Chinese, French, Greek, German or Spanish, depending on the native language of the posters?
 

Offline Jon Chandler

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Re: A few hundred dollars: which function generator should I buy?
« Reply #5 on: September 25, 2011, 03:34:08 pm »
Geez guys, lighten up. 

If somebody makes a request that's too vague, don't answer it.  Somebody else will, or the original poster can provide more info when nobody replies.

Hei !

det er bare å ha litt tolmodighet , så finner du billige og gode generatorer på ebay.
Dette er et greit firma i England som har gode varer til rett pris.

http://stewart-of-reading.co.uk/Signal%20Generators.htm

Mvh
Erik, Asker/Heggedal

And as far as a quick reply to a countryman in their native tongue, use Google translate if you feel so threatened!  It literally took 5 seconds to find out what the mesage said:

Quote
Hello!

it's just having a little patience, you can find cheap and good generators on ebay.
This is a good company in England that have good products at the right price.

http://stewart-of-reading.co.uk/Signal% 20Generators.htm

Regards
Erik, Asker / Heggedal
 

Offline king.oslo

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Re: A few hundred dollars: which function generator should I buy?
« Reply #6 on: September 25, 2011, 03:40:18 pm »
Can I get generators making digital signals in the common standards that PICs use? What is this feature called?

Thanks.M
 

Offline joelby

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Re: A few hundred dollars: which function generator should I buy?
« Reply #7 on: September 25, 2011, 03:47:33 pm »
You could generate square waves with Vhigh = 3.3V or 5V and Vlow = 0V, if that's what you mean? Look for CMOS/TTL outputs, or at least a maximum amplitude of at least as high as your PIC's supply voltage.
 

Offline king.oslo

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Re: A few hundred dollars: which function generator should I buy?
« Reply #8 on: September 25, 2011, 03:55:25 pm »
I want to simulate communications between two PICs, using one PIC and a a generator. I want to output a digital signal, say SPI or RS232 that the PIC can use to change the angle of a servo.

Thanks.M
 

Offline DaveW

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Re: A few hundred dollars: which function generator should I buy?
« Reply #9 on: September 25, 2011, 03:57:55 pm »
The buspirate will do what you want, or simply an RS-232 to ttl adapter and hyperterminal
 

Offline joelby

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Re: A few hundred dollars: which function generator should I buy?
« Reply #10 on: September 25, 2011, 03:59:17 pm »
You could theoretically do RS232 with an AWG, within the limits of waveform sizes and sample rates, but it would be far cheaper and far, far easier to get a Bus Pirate and a PC with a terminal program.

SPI requires at least two lines (data and clock) so you'd either need a dual-output AWG or two of them.
 

Offline king.oslo

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Re: A few hundred dollars: which function generator should I buy?
« Reply #11 on: September 25, 2011, 04:29:36 pm »
Yes the buspirate looks good!

Can i get a similar unit that is standalone and doesnt require a PC?

Thanks.M
 

alm

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Re: A few hundred dollars: which function generator should I buy?
« Reply #12 on: September 25, 2011, 05:52:12 pm »
Geez guys, lighten up. 

If somebody makes a request that's too vague, don't answer it.  Somebody else will, or the original poster can provide more info when nobody replies.
I don't see the issue, the replies asking for more information seemed polite and helpful to me. No replies could also indicate a lack of interest or that nobody knows the answer, and might prompt the poster to seek help somewhere else, where they will encounter the same issue until someone points it out to them.

Can I get generators making digital signals in the common standards that PICs use? What is this feature called?
A digital pattern generator would be the generic name. Serial host adapters, like the Total Phase products, would be a more specialized variant. Technically any signal or pulse generator that can generate square waves or pulse trains can generate a digital signal, although most digital buses tend to be more complex than that.

Can i get a similar unit that is standalone and doesnt require a PC?
Just like with arbitrary waveform generators, you really need a PC to load/setup the relatively complex signal. Not much fun inputting all data points on a front panel. Arbitrary waveform generators may have a front panel, but nobody uses that to set up arbitrary waveforms, only to generate the standard signals or recall a previously saved waveform. I guess you could connect a bus pirate to a serial terminal and make it a stand-alone product, but I'm not aware of anyone who did this. You usually have a PC around when doing digital development/troubleshooting anyway for stuff like programming/debugging a micro or running a logic analyzer. Some specialized test gear with limited flexibility (eg. TV test signal generators) may have a stand-alone interface.

When we Norwegians has conquered all the world, You all will speak Norwegian!
Sorry, wrong millennium. That was about a thousand years ago ;).
 

Offline king.oslo

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Re: A few hundred dollars: which function generator should I buy?
« Reply #13 on: September 25, 2011, 07:10:26 pm »
Thanks!M
 

Offline Kiriakos-GR

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Re: A few hundred dollars: which function generator should I buy?
« Reply #14 on: September 25, 2011, 09:09:16 pm »
so, not the vikings, the Norwegian investors are coming to get You!

Alm I like to see your face after reading the above reply,  please send me a picture of it   LOL ... Oh my  :D
 

Offline westfw

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Re: A few hundred dollars: which function generator should I buy?
« Reply #15 on: September 25, 2011, 09:10:45 pm »
Quote
I want to output a digital signal, say SPI or RS232 that the PIC can use to change the angle of a servo.
I don't think that this would normally be called a 'signal generator'...
The "bus pirate" is a good suggestion; otherwise you start to look into specialized and expensive "SPI analyzer", "I2C analyzer", "serial protocol analyzer", "traffic generator", etc.

Another idea is an Arduino, a PC, and a small amount of programming.  Though that would give you two things to debug, when I expect that you wanted a "known good" traffic generator.
 

Offline bilko

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Re: A few hundred dollars: which function generator should I buy?
« Reply #16 on: September 25, 2011, 09:14:15 pm »


Norway's Fund Invests $722 Million in Property in London's Regent Street
http://www.bloomberg.com/news/2010-11-04/norway-fund-invests-722-million-in-properties-in-london-s-regent-street.html


so, not the vikings, the Norwegian investors are coming to get You!

So what's the big deal, about 12 houses then :)
 

Offline king.oslo

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Re: A few hundred dollars: which function generator should I buy?
« Reply #17 on: September 25, 2011, 10:36:16 pm »
Kanskje det er en idé å ikke snakke så mye om nasjonaliteten vår. Vi er stolte, men kanskje noen blir misunnelige eller sinte ;)

Anyway, eventually I bought a BusPirate v3.M
 

Offline Kiriakos-GR

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Re: A few hundred dollars: which function generator should I buy?
« Reply #18 on: September 25, 2011, 11:13:27 pm »
Beyond the fun and the jokes among us, its true that some people have some difficulty to understand how hard it is for all the non native English speakers, to participate in forums with a mixture of English and American English language.
The ones who does that, are smart - educated - and love to communicate.
And imagine that we do not speak about vacations and simple terms, but about technology, that many best educated in English language will fail to handle the technical terms !!

Either way Alm is an very educated person about technology, and I am greatly appreciate him.  :)

And by the way, forget the function generator and make more international friends.

Also, after all this statements about Norway, if any Norwegian cry out again about the pricing of technical instruments
in Norway, I will kick his ass .  ;D  ;D  ;D   

 
 

Offline joelby

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Re: A few hundred dollars: which function generator should I buy?
« Reply #19 on: September 25, 2011, 11:45:30 pm »
Can i get a similar unit that is standalone and doesnt require a PC?

If you only need to send a couple of different messages, you could connect a bunch of buttons to another PIC and program it to send a message for each button.
 

Offline gregariz

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Re: A few hundred dollars: which function generator should I buy?
« Reply #20 on: September 25, 2011, 11:51:47 pm »
if you are wanting to just sniff or probe I2C/SPI words there are several usb modules out there that let you do it for $20 or $30. Sparkfun has one... there's another one being advertised in the mags... cant remember which one sorry.
 

alm

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Re: A few hundred dollars: which function generator should I buy?
« Reply #21 on: September 26, 2011, 12:14:15 am »
I have nothing against Norway, and I wouldn't mind learning Norsk once our neo-viking overlords rule the world, it's just another Indo-European language after all. Until the time that most of the world population (or at least the EEs) have learned Norsk, however, I suggest that communicating in English is the most effective for an international audience. One common language is the most effective on a global forum like this, didn't we learn anything from Babel?

On topic:
Interfacing with a bus pirate, like joelby suggests, would be quite easy, since it's just an async serial (like RS-232) connection plus an FT-232 to convert it to USB. There wouldn't be much point, however, might as well implement whatever protocol you need directly. The Bus Pirate is a very versatile swiss-army knife of slow serial protocols. It's not particularly good at anything in particular, transfer speeds are limited, for example, but it's very useful for quick and dirty jobs. This versatility and design for interactive use basically requires a keyboard, in my opinion, and does not lend itself very well to a few dedicated buttons.

Same for most SPI/I2C host devices, since they are designed to send and receive streams of data. Where are you going to put this data or get this data from in a piece of stand-alone equipment, unless it incorporates almost a complete PC?
« Last Edit: September 26, 2011, 12:16:05 am by alm »
 

Offline Mechatrommer

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Re: A few hundred dollars: which function generator should I buy?
« Reply #22 on: September 26, 2011, 05:08:35 am »
Can i get a similar unit that is standalone and doesnt require a PC?
If you only need to send a couple of different messages, you could connect a bunch of buttons to another PIC and program it to send a message for each button.
still require a PC. btw, i dont see it helpful talking in other language other than standard english. i can talk my language, but i will talk to myself then, or other people from my country only.
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 

Offline joelby

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Re: A few hundred dollars: which function generator should I buy?
« Reply #23 on: September 26, 2011, 05:19:46 am »
still require a PC.

Only the first time - after that it's a standalone piece of test equipment!

I'm assuming that the person asking the question has a PC and a PIC programmer because they've mentioned using PICs and have posted here using a computer of some sort.
 

Offline king.oslo

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Re: A few hundred dollars: which function generator should I buy?
« Reply #24 on: September 26, 2011, 07:46:20 am »
I am sorry, if anyone was offended by my use of Norwegian on this forum. At least on behalf of me, I would use English for anything other than irrelevant bullshit. So that those who don't understand what has been said, is probably not missing out on anything good.

Thanks.

Kind regards,
Marius
« Last Edit: September 26, 2011, 08:39:37 pm by king.oslo »
 


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