sound recording chip - Page 1
Forum section: electronics / projects

author: Simon
author_rank: Unknown
timestamp: July 13, 2016, 06:48:40 am
content: I need a sound recording chip that you press a button on to record a sound and then press a button to play it back. any ideas ? Ant searches come up with alibaba products that I'm not entirely sure of. I've seen lots of chip on board stuff on ebay but in my case i need to build it into a box and have connectors etc so I need to roll my own PCB and chip on board is certainly a no.

author: Kilrah
author_rank: Unknown
timestamp: July 13, 2016, 07:42:56 am
content: The ISD chips were quite popular for that purpose some relatively long time ago... not sure if you still can find some.http://www.scary-terry.com/dsr/dsr.htmhttp://www.kitsrus.com/pdf/isd_2560.pdf

author: MK14
author_rank: Super Contributor
timestamp: July 13, 2016, 08:46:11 am
content: Just in case it's not obvious. I mean buy THAT chip. Find out where you can source it from, if you want to make your own boards from it.It might just be a standard, cheap microcontroller, such as pic, with a program to perform this function, I guess, without looking at it in great detail.https://www.amazon.co.uk/ISD1820-Voice-Recording-Playback-Module/dp/B00JQ2IMHG/ref=pd_sim_201_4?ie=UTF8&dpID=5117SQeEWGL&dpSrc=sims&preST=_AC_UL160_SR160%2C160_&psc=1&refRID=AE1G3XSZ5XJ0JY60JM3Ghttp://www.datasheet-pdf.info/entry/ISD1820http://gotronik.pl/img/isd1820_module_manual_v01.pdf

author: timb
author_rank: Super Contributor
timestamp: July 13, 2016, 01:03:16 pm
content: I have one of those ISD chips, brand new in the package that I bought in ~1996 at Radio Shack. I think it holds 30 seconds of audio?If someone needs it for a one-off project, let me know and I'll send it on.It was a pretty neat technology, actually.Essentially, the chip contained EEPROM type cells and for playback, instead of detecting if the charge in each cell is over a specific threshold (to determine if it's a one or zero, as would be the case with a ROM used for digital storage), they use the voltage directly, amplifying and buffering it to drive the speaker. The reverse happens for recording.So it's literally storing the entire analog waveform on the chip, in an analog form. There's no AD/DA conversion going on! They even made PROM versions that could be programmed once (via a dongle or at the factory) and played back indefinitely.I think Winbond bought ISD in the early 2000's and they pretty much stopped selling to low volume and hobbyist customers. Then high quality audio codec chips flooded the market and the bottom fell out on flash prices. Combine that with cheap micro controllers and it became cheaper to use digital recording and playback for answering machines and the like.Though, from about 1993 to 1999 I'm sure ISD sold a ton of those Chipcorders! I remember these things called "YakBaks" being really popular when I was about 12 or 13 (around '96). They were little handheld recorders with just a button and a speaker; it would record 15 seconds of audio and let you play it back; you could speed it up or slow it down, too. I read somewhere they used a cut down "CoB" version of an ISD chip.They were also used in tapeless answering machines which became hugely popular around that time.Shame they faded away. It was a really cool technology!

author: MK14
author_rank: Super Contributor
timestamp: July 13, 2016, 01:30:22 pm
content: Quote from: timb on July 13, 2016, 01:03:16 pmThat is AMAZING, and really cute and clever, to use the actual EEPROM cell voltages, as the analogue output signal.But I'm confused as to how that could work with a built in PROM.On reflection, I guess the "PROM" was really a "Write Once", EEPROM really.My initial confusion was because I was thinking of production mask ROMs, which would only produce 0's and 1's, hence NO analogue output signals.Anyway, smart idea.I'm still somewhat convinced that these modern ones, are a cheap (almost re-purposed) standard PIC or similar simple (not too simple) microcontroller. With a program which uses the PWMs or DACs or whatever I/O etc it has, to create the functionality.But it could be a simple custom IC. I just would have thought the potential sales are far too limited to design a custom IC (ASIC or whatever) to do that. Maybe it was one of those "shared mask" chips and/or someones PHD or something ?Or they copied/used an earlier design and/or its masks ?Although one would have thought it would be too out of date, to still make ?EDIT:Maybe the potential market, is the massive specialty "birthday" card market. Personalized messages being potentially popular and/or answer phone message recorders (as you mentioned/hinted in your post).

author: timb
author_rank: Super Contributor
timestamp: July 13, 2016, 01:49:17 pm
content: Quote from: MK14 on July 13, 2016, 01:30:22 pmI don't think the original analog Chipcorder technology is produced anymore, at least not widely available.Winbond makes audio codec chips as well (a codec is basically a multichannel audio ADC and DAC on a chip), so I'd hazard a guess current generation "solid state recorder" chips just contain an ADC, DAC, flash and a simple MCU (like an 8051). The MCU might not even be needed, since you could put the ADC, DAC and flash all on the same data bus and use some simple logic to control the CS and address pins for recording and playback. I imagine most things, like answering machines and memo recorders have gone this route.And yes, when I said PROM what I really meant would be more akin to WORM and not a mask ROM. An example of this use would be an answering machine that verbally time stamped messages. So you'd have a couple of these ISD chips, giving you 10 or 15 minutes recording time, and a *portion* of one of them would have been pre-programmed with someone speaking various digits (one, two, three, etc.) and key phrases (o'clock, AM, PM and so on). Then, that portion would have been permanently locked (by blowing a fuse), so it couldn't be recorded over.The other neat thing is, since the storage worked like an EEPROM, it was addressable. You could instantly jump to any section for record or playback.It was a very clever architecture, it's a shame someone didn't think of it earlier. I imagine it would have been very popular in the mid to late 70s or 80s!Edit: Now, those greeting cards might still use a variation of the Chipcorder technology! I seem to recall reading something to that effect. Hmm...

author: MK14
author_rank: Super Contributor
timestamp: July 13, 2016, 03:58:45 pm
content: Quote from: timb on July 13, 2016, 01:49:17 pmYes, in their day, those were interesting chips.In the 1970's, chips were rather expensive, and ram/rom/EEPROM etc, were both pricey AND very small capacity. So it may have been a bit too early then.E.g. In 1977 and later, A Science of Cambridge (Sinclair) MK14 microcomputer Kit, had a massive 256 bytes of ram to play with (as standard).But the 1980's could have been an option.Ignoring volatility issues. CCD (Charge coupled devices), would also make a natural analogue in, analogue out, chip concept. Assuming the CCD could have enough storage cells, for the recordings. Since early ones were rather small (256 if I remember correctly).I would imagine the chips must be (whatever they use these days) incredibly cheap, somewhere (probably China), since the entire sound recording unit, assembled PCB with Mic and other components, sells for about £2.16. So the chip alone maybe £0.10 to £0.25 (guess).If it was me, I'd buy say 50 (if that is what a customer wants) of the board. They probably can be bought fairly cheaply in bulk, since they retail for about £2.16Why bother making your own PCB ?When I can just buy the ready made modules, for maybe a £1 or thereabouts.I guess another $64,000,000 question is, how cheap an MCU, would it take to make such a device, and how long would it take a competent engineer to design the software for it ?It's a pity the PSOC5 stuff, does not come with the option to buy their chips, for extremely low (bulk) prices.$10.00 is fine for messing about, and very small scale production, and/or high value projects/goods.But for simple things, a £0.35 part (even with reduced capabilities), would massively increase the chips utility.I know they (Cypress) do sell partially cheaper parts (PSOC4 etc), but when I last checked, they are still somewhat pricey.That's my dilemma with it, because there are so many low cost MCU's available these days, such as Arm(ST and others)/PIC etc.I guess they CAN'T get the sales volume and/or it is too expensive to manufacture.The PSOC5 would probably very quickly and easily be programmed up to do functionality like this. Just too expensive in high volume production.

author: Kilrah
author_rank: Unknown
timestamp: July 13, 2016, 05:44:02 pm
content: Quote from: timb on July 13, 2016, 01:03:16 pmWow very interesting, never knew that!

author: timb
author_rank: Super Contributor
timestamp: July 13, 2016, 11:14:13 pm
content: Quote from: MK14 on July 13, 2016, 03:58:45 pmIt doesn't take a lot to do this, actually. I've done audio playback with a <$1 MSP430. Basically you take an 8-bit WAV file and convert it to a an array of HEX bytes that you paste into your C code. Then you use that to control a PWM output, which you run through a LPF and--depending on how big the speaker is--buffer.It takes very little processing power to do and, if I needed longer storage I could easily use SPI flash or an SD card. Assuming you only need 15 seconds of audio and a very small speaker like in a greeting card, I could do it all with nothing but a single MCU and a couple of tiny caps and resistors.Recording is a different story, however, wouldn't be that complex. The 8-bit ADC on my MSP430 might be able to do it, however if it couldn't keep up, then you could just use one of those digital MEMS microphones.

author: Engineer_EE_FW_SW
author_rank: Newbie
timestamp: July 14, 2016, 12:07:33 am
content: Nuvoton now sells the ISD Chipcorder products and I'm fairly certain that they do still sell the analog FLASH cell based record and playback devices since I did a design with one of their playback only devices a while back and the analog record/play devices were still shown as available / stocked at DigiKey and at Nutovon's own site.http://www.nuvoton.com/hq/products/isd-voice-ics/isd-chipcorder-family/?__locale=enProgramming a low end 8/16/32 bit MCU to record and play 16-bit PCM or uLaw/A-Law digtized audio from an SPI FLASH/EEPROM chip is an afternoon's work or less, and designing the board also would probably be a day's work if there aren't particular BOM cost / sourcing / physical size / low power restrictions that complicate the design beyond the audio functional necessities.Using MP3 or OGG Vorbis encoding formats to augment audio storage capacity per megabyte if implemented in software would likely make something more like a low to mid range Cortex M0 desirable, and would be more involved.There are playback only decoder libraries commonly available though patents / licensing might complicate the situation for MP3 as opposed to an open format.There are ASSPs that do MP3 and OGG formats:http://www.vlsi.fi/en/products/vs1053.htmlI believe others have cited some of the low cost Asia-Pacific origin modules and ICs. I've got notes on them somewhere from that past project but not handy at the moment.

author: Simon
author_rank: Unknown
timestamp: July 14, 2016, 04:42:17 pm
content: Quote from: Kilrah on July 13, 2016, 07:42:56 amThank you all for your comments. Unfortunately those chips only work at 8 kHz and I'm trying to reproduce a click sound which I believe has a frequency of 6 kHz so realistically I want as much sampling as possible as my clip duration is so short I would have plenty of memory. I have found a chip on Ali Baba the NV85B which apparently they supply pre-recorded with the sound of your choice so that may well be an option if I can't generate it in hardware or with analogue. I'm exploring a Wayne oscillator with a low gain that does not properly oscillate but just produces a click and my other option is to try and reproduce it from an atmel for example the attiny85 has a 64 MHz frequency for the PWM if you use the internal PLL.

author: Someone
author_rank: Super Contributor
timestamp: July 14, 2016, 11:05:36 pm
content: Quote from: Simon on July 14, 2016, 04:42:17 pmRepeat of previous thread?:https://www.eevblog.com/forum/microcontrollers/generating-a-sound/

author: nctnico
author_rank: Super Contributor
timestamp: July 14, 2016, 11:24:53 pm
content: When going for a digital solution: use a-law or u-law dynamics compression using look-up tables. That way you get 12 bit (or more -I forgot-) dynamic range from 8 bits.

author: Buriedcode
author_rank: Super Contributor
timestamp: July 15, 2016, 01:13:54 am
content: The last thread about generating sound covered a lot of ground because I'm not sure folks knew the specifics of the application (sound quality, length of sound clip etc..).To the OP, if you're just making a 'click sound', what have you tried so far?I think from the other thread it was mentioned that you can either generate the sound with some sort of custom algorithm - a one-trick pony - or use the generic method of playing sounds with an MCU (with PWM) and off-board memory should the sound clip be long. The latter has the benefit of you just looking for a sound clip that sounds right, sampling it, and putting it in flash. If it is a particularly simple sound that's short, you could record it, and view its waveform to see the envelope, and transients and try to reconstruct something similar using a bit of maths.For a simple 'click' I think a micro with PWM and a low pass filter is probably overkill, but it is also surprisingly cheap and versatile. For < 20 units it might be the way to go, for >20 then of course you'll either want a dedicated chip - which are expensive and rare these days - or the cheapest little micro you can find with some clever code.Perhaps an example of the sort of sound you want would get the thread going in a more helpful direction?

author: Engineer_EE_FW_SW
author_rank: Newbie
timestamp: July 15, 2016, 03:28:55 am
content: Some of the newer digital storage type NUVOTON chipcorder ICs I have used can record and playback audio including at some extended sample rates / fidelities, I just didn't know that was relevant to your application.But it seems there is little advantage in using them over a basic MCU particularly if the on-chip or external serial FLASH is big enough for relatively uncompressed audio. The larger on-chip FLASH, the built in output amplifier / analog audio interface, and the compression modes they support are the main reasons (other than simplicity of use) that someone might use the chipcorder parts.Also look at 'haptic' related ICs, not the vibration drivers but I think there are similar sound effect generators that are intended for UI sound generation like beeps, clicks, ticks, etc. Look at Nuvoton, Holtek, and whatever else you can find, there are probably good solutions to play back the click impulse as standard products. Many might not record as easily as they play back but I suppose some will. I'm not quite sure why a UI "click" sound would needed to be re-recorded other than in R&D and for master production. If you can optimize for playback and record only in the factory that could simplify things and lower costs. A $0.45 MCU could probably do playback fine, though based on an effects generation synthesis sort of technique rather than actual PCM samples.Edited for application relevance / correction.

author: Simon
author_rank: Unknown
timestamp: July 15, 2016, 06:28:40 am
content: I'd rather use a sound recording chip than an MCU but that has been considered. The chip i found is pre-recorded for me by the manufacturer which can be a bonus. I'm putting this into a commercial product so repeatability and stability (no overclocking?) are important.

author: MK14
author_rank: Super Contributor
timestamp: July 15, 2016, 07:31:37 am
content: ISD2360SYI 16 pin SOP, other packages availablehttp://www.digikey.co.uk/product-detail/en/nuvoton-technology-corporation-of-america/ISD2360SYI/ISD2360SYI-ND/3507392http://media.digikey.com/pdf/Data%20Sheets/Nuvoton%20PDFs/ISD2360_Brief.pdfIt seems quite nice (at a quick glance). For 5000 of, it would be about 97 pence + maybe other costs.But having a 1 watt class D 8 Ohm speaker driver, the flash and powerful compression built in, allowing up to 32 KHz sampling quality, and other things, makes it look nice to play with.Although it probably won't be suitable for the OP, since it is too expensive, too high quality (lower quality may be cheaper), too complicated (so would take too long to develop), etc etc.But I'd love to play with one, if I had the time!

author: Fungus
author_rank: Super Contributor
timestamp: July 15, 2016, 11:10:32 am
content: Quote from: Simon on July 14, 2016, 04:42:17 pmIf it's just a short click and you know your way around an AVR chip then a Tiny85 would be the way to go:I assume you've read this:http://www.atmel.com/Images/Atmel-2542-Using-the-AVR-High-speed-PWM_ApplicationNote_AVR131.pdf

author: Buriedcode
author_rank: Super Contributor
timestamp: July 15, 2016, 11:12:34 am
content: I take it the product you are making doesn't have a microcontroller already in it? and you mentioned you would prefer not to have a module, COB but rather a single chip, prerecorded or otherwise?Still waiting for an example of the sound you want

author: Simon
author_rank: Unknown
timestamp: July 15, 2016, 12:02:47 pm
content: The sound i need is a click like you get from a handheld device that has a mechanical button and diaphragm under it, you press it clicks, you release it clicks as the diaphram is forced either way. the actual sound that I can tell from stripping the audio from a video fie is a decaying 6KHz oscillation lasting a few ms. there is no other MCU involved I just need the device to make this sound so if i use an MCU it will be just to make the sound.

author: alexanderbrevig
author_rank: Frequent Contributor
timestamp: July 15, 2016, 12:23:51 pm
content: Maybe you could design a circuit that simulates the sound? A 555 at 6kHz shaped to sinusoidal (maybe harmonics from square wave would sound better? Take that into a transistor and set the gate. You could make it fade out using an RC to make it fade?Not sure it's viable but it might?EDIT: of course not viable if you need recording in the product.

author: Simon
author_rank: Unknown
timestamp: July 15, 2016, 12:44:02 pm
content: Quote from: alexanderbrevig on July 15, 2016, 12:23:51 pmI tried using a signal generator to make 6Khz and pulse it but to no avail so yes it defenitly needs to decay, I'm sure it can be done in analogue but by the time it's done I could probably have the chip preprogrammed from china.

author: Fungus
author_rank: Super Contributor
timestamp: July 15, 2016, 07:50:07 pm
content: Quote from: Simon on July 15, 2016, 12:02:47 pmThat's a perfectly legitimate use of an MCU.

author: MK14
author_rank: Super Contributor
timestamp: July 15, 2016, 08:16:17 pm
content: Quote from: Fungus on July 15, 2016, 07:50:07 pmAs long as it is a hobby project, or commercial one done out of personal pleasure and education, rather than financial gain, then yes.But if it is commercial, and the sales volume is relatively small (apparently mention in the other thread, I think it seemed to mention up to 50, at a time), then the engineering time to create it, may not be worth it. If off the shelf special purpose ICs are available at the right specification and price.Someone who does this sort of thing a lot, and is familiar with this type of product, maybe could program one up, fairly quickly. But if that is not the case, it can be quite a mouthful.If the customer is paying for your time, at each stage of the project, then fair enough. Give them options, and let them decide.But if that is not the case, you might spend tens or even hundreds of hours messing about, programming an MCU and getting the hardware just right. Then the customer says "they don't like it", and you get nothing and/or they only buy two of the devices at £0.99 each.

author: Fungus
author_rank: Super Contributor
timestamp: July 15, 2016, 09:05:37 pm
content: Quote from: MK14 on July 15, 2016, 08:16:17 pmThat's why I said "if you know your way around an AVR chip".I could easily do it in a morning but if you're not a coder then it could take a long time, yes.(not sure if it would be "hundreds of hours" though...)The other factor is price: Tiny85s can get expensive if you need a lot of them. If you need large quantities then I'm sure there's somebody in China who can do it much cheaper (think birthday card chips).

author: MK14
author_rank: Super Contributor
timestamp: July 15, 2016, 09:40:28 pm
content: Quote from: Fungus on July 15, 2016, 09:05:37 pmI'm still not very clear what exactly the specifications of what is being done, as regards this thing is, anyway. How loud does it need to be, Operating voltage, power consumption (battery/mains ?), target/max cost per item, size, likely min/max production volumes, profit margins needed, payment per hour or per item, etc etc. But maybe it does not really matter for the purposes of this thread, and I'm throwing my toys out of the pram.I'm not surprised if estimates on how long it will take, vary immensely widely.A lot depends on the person doing it. The same program might take an expert 1 hour, but a beginner may take all week.Also it is much quicker to do a rough and ready, quick prototype. Than proper serious/robust software, which goes into mass production, and needs to help keep costs low, and be completely reliable.

author: Simon
author_rank: Unknown
timestamp: July 16, 2016, 06:46:59 am
content: It's battery operated, 5-6V. Yes first batch is 50 after that it's how many my customer feels she can sell. I have a sample sound so I don't need to create it. If I had no sound I'd consider an MCU first.

author: MK14
author_rank: Super Contributor
timestamp: July 16, 2016, 07:11:25 am
content: Quote from: Simon on July 16, 2016, 06:46:59 amThat makes an MCU sound like the best solution. Then if you get bigger volume orders in the future, you are set to go, with a very low cost parts cost (hopefully), and you can get them made up (where you are, or elsewhere).The specialist chips seem a bit pricey (compared to low cost MCUs), and may not always be available. That's assuming you can get it to work with acceptable quality, in a very cheap MCU.Although you can get seriously cheap MCUs, as you start increasing the specs of them, the price can still go up a lot. Hopefully the really cheap ones can have a powerful enough PWM, enough flash and other stuff, for this application.You previously mentioned using a specific MCU, but if the quantities become large, it might add a significant amount to the cost.If you can write the code in C/C++ on your favorite MCU, it should work in the cheapest one (that is good enough for your functionality). Except that the I/O parts, will have to be rewritten. Hopefully that would only be 10% of the code.I'm just assuming that price is very important, if they buy in volume. If it is not then freely use the MCU of your choice, I guess.If you want the cheapest possible MCU, then you have to accept it might not be your favorite MCU.Getting things to work on really cheap MCUs can be hard, and is not always possible. Maybe price is not that important, I don't know yet. It is not immediately obvious from the original posts.tl;drWould a £0.20 MCU be ok ?Would a £2.00 MCU be the end of the world ?How critical is the sound quality, which is more important, quality or MCU cost ?

author: Simon
author_rank: Unknown
timestamp: July 16, 2016, 07:19:07 am
content: Well considering that the plastic box the whole thing goes in is going to cost around £5 and the circuit board is another couple of pounds £1 for a chip is not bad. With the quantities I am dealing with taking 50p out of the price is not going to save me a lot of money and I'm not overly impressed on price but obviously it does need to be reasonable. The problem I have at the moment is the time to write the code so if I can just get something off-the-shelf that they program for me that would be a bonus. If a device had wider functionality then maybe it would make sense to put this into a microcontroller as part of other functions but this is all the device needs to do.

author: MK14
author_rank: Super Contributor
timestamp: July 16, 2016, 07:30:59 am
content: Quote from: Simon on July 16, 2016, 07:19:07 amIt should be really quick, and relatively straight forward, to write that code. All it is really doing, is reading through a big array/rom of sound data values, sending them to the PWM, until finished.PWMs can be a bit of a pain to set up and get working with the right timing. You probably will need at least one timer as well (you might get away without using one), so you can accurately control the timing of the playback, without having to worry about how fast your loop executes.At around the £1 mark, there is a wide variety of devices on the market. I guess the PWM functionality/specs and size of flash (for the sounds), will help you choose one.There are a number of very low cost (like £10) MCU development boards floating around, take your PIC (pun intended).If the MCU you have at the moment has a suitable PWM, you could start with that.ST Arm chips, and some PIC chips, seem to be quite popular on this forum.Similarly the prototype hardware, sounds (ignore the pun), really simple and could easily be built on the proto area of the MCU dev board, or via a small breadboard initially. Just a few capacitors and resistors etc.