I am a CPA, in completely over my head, building a prototype keychain game. In this game, I need to use two audible signals, a chime when you score a point, a slightly different "unpleasant" chime when you lose a point.
My device is 35 X 25 X 9 mm; I would like to use a chime like one found in a wristwatch. It needs to be small, and about that loud.
I have found a piezo buzzer, 5mm, but I'm not sure what they can sound like. They also seem to draw a lot of power, and are 85-100db, which sounds loud.
Am I even in the correct forum? What is that part? Where can I get sample quantities?
Maybe sci.electronics basics would be better, dunno, and not sure off hand. If you're that far over your head, what's involved in the rest of the game? Electronics beyond driving a piezo?
You can check Mouser and Digikey for the part and the sales rep may be able to arrange samples. I saw a piezo company maybe a year ago, and if you google enough, you'll find one, and either they or a rep can arrange for samples. The one I found was in UK, IIRC, so maybe that's not for you. I just needed some tech info.
There's 2 types, also. Self-oscillating and the one you supply a tone to. If you try to apply a frequency to the former that is not the same as the resonant freq, you may get the kind of unpleasant discordance you're looking for. Maybe not.
Can you give us the specs of the one you've found? The 5mm part.
OK, let me try once more... I keep losing my messages, a huge case of user error.
The links to two products, I can't tell the difference:
formatting link
formatting link
If there's anything else out on the site that looks like what I need, please let me know.
Essentially, my problems are:
1) Don't know the part I'm looking for
2) Don't know what the specs mean to get what I'm looking for
3) Don't know the terminology or science
4) Can't find internet descriptions that I can understand
5) I've got to find the right size ( 5 - 6 mm diameter, max)
For instance, am I looking for a piezo, buzzer, sounder, transducer, are they all one and the same? What kind of part? What do I need to do to drive it?
What is the part called that chimes in a wristwatch?
Digi-Key and Mouser have piezo's that are too large. And back to basics, I'm still not sure that's what I'm looking for.
The info about the two types, and that I don't have to drive so hard is helpful and encouraging...
Basically, the device is a microprocessor, some buttons and an LCD. While learning this is not "easy", it is well documented, and fairly well supported. It doesn't take too long to get functional with those things.
This sound thing though, is another story. I don't understand it, it is not that well explained anywhere I can find, and so I'm swimming in a sea of data with no way to convert it to meaning.
Yes, microcontroller, I am new at this... you're right.
As you have described, I haven't found any high level descriptions (like "piezos can be used for creating beeps and buzzers" or "a transducer can be used as a small speaker"), instead they are much more detailed, including the Google define: descriptions. Ultimately, I'm confident I'll understand what they mean, but for now, I'm afraid I'm lost.
re: your PWM paragraph, this is exactly the kind of push-start I need to simply point me in the right direction... I didn't want to go to the trouble of getting some parts if they were not what I needed, and waste a lot of time, as valuable as that might be in the long run. Thanks.
re: "not self-oscillating", you said earlier that was the kind I'd have to supply a tone to...I'm guessing that your earlier description about the PWM, the period and the duty cycle is how I would supply that tone?
At
formatting link
I found a discussion about attenuation. I don't pretend to understand it right now, but I get the point that the output needs to be filtered and adjusted. At any rate, it is specific enough, that with a little bit of trial and error and documentation, I can probably stumble my way into an answer.
Thanks Mike,
I'm happy to keep this thread open in case you think of anything else. I've sent my first correspondence to the ARIOSE company, I'll see what they have to say.
If posting from google... YMMV. ISPs, same. I used to change Earthlink servers when they fouled up.
Anyone want to give a second opinion on whether those little speakers are made for AC input as opposed to self-oscillating piezos?
Maybe when I have time later. Those two buggers above look like they only differ by the freq response.
Google every word you don't understand. First keyword "define" with no quotes sometimes works well.
But those parts above are not piezo devices. They could very well work, though. I can't find anything that small in piezo in my cats, so I'm ready to recommend trying it. If by microprocessor, you mean microcontroller, like a PIC or Atmel AVR, you're in like Flynn. One trick is to use the PWM output and vary the period (1/freq) while holding the duty cycle at 50%. Then you can make any tone you want withing the freq response of the noise maker. The flattest part of the response curve will give you the least variation in sound pressure level. It might not look flat, but practically speaking, the lower part of the curve looks like the range you'd want for chimes. Say 1-3 kHz. That's an octave and a half. You could go lower probably.
PWM - Pulse Width Modulation.
It also looks like the max and operating voltages are specified as peak voltage and they give a coil resistance, so I doubt it's self-oscillating. The package, however, dictates the resonant freq, and operating away from that may or may not sound weird. I doubt they're too expensive, so they may be worth a try.
Much of it's more technical than you need.
You have, IMO.
Forget buzzers and sounders. Drive it like I said above (PWM). You'll probably need to attenuate the PWM output. I gotta run, so I'll think about it more later and we can talk about attenuation.
I always assumed they are piezo devices. I could be wrong.
george.alvarez (aka scoremind) wrote: [a post with no context]
Notice how Active8 includes part of your post when he responds? People who don't read this at Google don't see Usenet the way you do. Observe how others post and do likewise.
Something to read for a Usenet newbie who posts at Google:
A piezo crystal flexes when you apply voltage to it, so when you apply a varying voltage, it vibrates. That's the gist.
Yup.
Yeah. I blew that app-note off because everything I needed to know to implement PWM is in the datasheet for the chip in question. The self oscillating piezos, buzzers, and sounders operate when you apply a DC voltage. Regular piezos, speakers, transducers ( a speaker is a transducer if you want to use the $20 word) operate from an AC signal.
KISS (keep it simple stupid) method is to rig a volume control (pot or potentiometer) between the PWM out and the speaker and once you get the volume level, measure the resistance between the wiper and both ends and there's your attenuator.
View in fixed width font. See the link for that up top if posting from google.
PWM ---+ | .-. R1 .---| | | Thanks Mike,
Sure.
Good move. If you have any probs with mfg reps getting parts, they'll probably do your bitching for you and light some fires.
If they confirm that it requires an AC voltage, I'll ( or just about anyone here) figger out the details of the filter and attn for you. Also get confirmation of WTF they mean with their operating and max voltage specs. I would expect a peak to peak spec or an RMS spec, not a peak spec like Vo-p. I'd expect Vpp or Vrms.
Rated Voltage(Vo-p): 3 Operating Voltage(Vo-p): 2.3 - 4 Current Consumption(mA): 100 max // does not compute with R below Coil Resistance(?): 12 +/-3
2.3 * .707 / 12 = 135 mA, which exceeds the max current spec. Maybe they need to put the crack pipe down.
Oh. Accuracy of your PIC timebase... I don't know what your game does, but if you don't need accurate timing, you can use the internal oscillator. Some PICs have a calibration word that makes it even more accurate. You probably don't need a crystal. Not if it's something like needing a timer to give the player a number of seconds to respond. There's a few ways to do that with or without a crystal.
I don't know what the PIC requirements are either. There's alot of info on the net for the 16f84 and it's obsolete. 16f628A/648A or
16f88A are nice chips, though.
formatting link
Randy ships fast and he won't rape your wallet. He's got PICs and support parts. Info too.
formatting link
is a good PIC info site. Great forum/mailing list for PIC and EE questions. Lots of novices trying to flash LEDs and such, as well as EE types.
||from the link: ::[for] context ::Easy way: Don't click the Reply link that is in plain sight. ::Click the **show options** link then click THAT Reply link
Well, I've always thought that the auto-blockquote "feature" of newsreaders (and of the old Google Groups) gets (got) abused. It makes folks lazy. Shoot, when I'm paring down the old text I often find things I missed the 1st time. To me, a lack of context is preferable [1] to gobs of extra junk (on which the response has no bearing). I especially love it when ALL of a 200-line disertation is reposted with a 4-word response.
That sucker is lying to you
--or is that their way of saying "2nd try at Google Groups"?
I have Super Gravity, but the only times I've used it was when I responded to somebody who had cross-posted to a whole slew of groups (Google won't allow responses to more than 5 groups) and when the Google Groups Beta was new and I had problems (I think I had AdBlock set too strict).
formatting link
Mostly I post at Google, so that shoots your theory all to hell. (That's the reason I know so many Google tricks.) I am, however, proof that someone can post at Google and not look like a newbie. [1] I actually like the interface. I can see a lot at one time and get context, no sweat. With the new low-latency updates (to the thread displays--not to the searchable database) it's not completely a pain the way it once was.
Yeah. Good point. The only reason I followed what was going on is because I got into it from the git go.
formatting link
IOW, the new google is hiding the quoted text. PITA. Good info about the "show options" link in that OT seg of the thread.
I'd recommend 40tude Dialog for a news reader. You are using G2/0.2 (never heard of it. Linux?) and between the two, neither news client mangled the long link he posted. That's cool.
If the OP doesn't like using his ISP's nntp server (slaver?) he can try
formatting link
for free unlimited posting since individual.net is going to start charging. Must all good things come to an end?
I didn't expect a user-agent header from google. WTF's the point of it?
Oops! "He" should have been "you". My head's still up my ass.
I used to use that but the reader group posters were bitching about the new versions and I gave it up. IIRC, it would alert me to replies (yeah a filter rule/action thing) and that was cool, but something got me wanting more so I looked into upgrading it. Now I run a script in Hamster personal nntp server and it alerts me to which group, subject, level, and poster - anything I can get from the header info - and I can import the reply to an internal group I create or a text file. You need a server like individual.net ( I hope the terra server will do it) that allows you to use them as an FQDN to generate the message ID - something like that. Dialog offers scoring, and people use that to guess whether a post is a reply to them, but I don't like that method.
It's getting fixed/improved and it isn't as bad as some have made it out to be. MS, OTOH, ... FUBAR
That works. Often, If I see an OT thread or even one that's on topic (or in our sister binaries group where I don't want to wait for the OP to download), and I want to get an idea if I should check it out, I'll jump to the middle and read a post from one of the bigger guns.
Quite a while back, someone (Watt Sun, IIRC) was adding padding to his posts to get arround some kind of filter.
I, OTOH, say brevity is the soul of wit[1]
--make it as short as communicates the intelligence.
I hardly ever do the **** thing. If I think editing the middle of the OP's post will leave a false impression, I use elipsises. (Man, it's hard to know when to stop typing on that word.) Otherwise, I chop out the excess.
Google is now flagging the posts that have the X-No-Archive bit set so it's obvious which posts you need to blockquote in their entirety.
What just facinates the hell out of me is when somebody reposts part of the original post BELOW THE LAST SENTENCE HE HIMSELF HAS ADDED.
[1] I'm not going to say that I said it 1st
--but, hey--if you're going to steal, steal from the best:
formatting link
(Good site to bookmark--the quotations attribution site.)
If you mean one letter per line, it was either him or Genome. I never figured out the purpose.
Ecomomy of words and motions is part of my philosophy. Sometimes I fail on the former.
Elipsis
Dialog warns me of that. Sometimes I blow it off. Many times, it's because the f*cking poster I'm replying to didn't use the double hyphen above the signature, so it gets quoted.
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.