picaxe sound schematic problem

[shah_siddiquee]

Hi. I am trying to make a sound detector for my picaxe. I made the picaxe_sound cicuit three times on breadbord. But i cant get a output signal as it says. I checked with meter, everytime it shows defferent constantan volt on output. Is anyone made that circuit? Can you tell me what is output volt, like is it +v or -v ? I dont understand the Third part of circuit. the third transistor is npn and the output is not on right place, i mean pin C of the trasistor should be the output. Please give me suggestion. Sorry i could not put any pdf link or diagram.

 

[PaulRB]

Do you mean this?

I have not tried the circuit myself, but it says the circuit will produce output voltage high enough to be recognised as "high" to a digital input.

I think, to get any help, you will need to post a good quality picture of your circuit and mention any component substitutions you made.

Paul

 

[russbow]

i mean pin C of the trasistor should be the output.

The output transistor us used as an Emitter Follower, so "pin c", the collector, is not the output pin.

Google emitter follower and you will get thousands of hits to help you understand.

 

[shah_siddiquee]

emmiter flows from base.

Many Thanks for replay. @ paul, i orderd all the parts from bitbox exactly what the diagram says. Also i tried on breadboard, so i removed all again. Today i will try again. What i did is, i seperate the cuircuit in three stage on breadboard. As i can see if there any mistake and test every transistors output in circuit.

In a NPN transister normaly current flows from emmiter to collector. Or if there is no trigger on base then current flows from base to emmiter.
If anyone made this circuit please help me. My knowladge is not so good at electronics. Thanks

 

[rossko57]

In a NPN transister normaly current flows from emmiter to collector.

Collector to emitter perhaps?
http://www.technologystudent.com/elec1/transis1.htm

the third transistor is npn and the output is not on right place, i mean pin C of the trasistor should be the output

Think about what happens when current flows out of the emitter and through the resistor to ground. What will the output voltage when no current is flowing? What does Ohms Law tell you about the output voltage when current is flowing through the resistor?

 

[shah_siddiquee]

picaxe sound circuit

Is thete anyone who made that picaxe sound circuit? I realy need a ampifire circuit for my analog input of my project.

 

[westaust55]

Shah,
You already have a thread current on the first page of this forum:
http://www.picaxeforum.co.uk/showthread.php?24283-picaxe-sound-schematic-problem

Please do not start duplicate threads as messages will get crossed and the overall chain of responses will be confusing.
It is also port forum etiquette (practice).

Furthermore, please provide a link to the webpage when you reference circuits, modules, chips, etc from elsewhere.
Not everyone knows what you mean by "that PICAXE sound circuit".

Later today when near a PC I will merge the two threads.

 

[Goeytex]

Hi. I am trying to make a sound detector for my picaxe. I made the picaxe_sound cicuit three times on breadbord. But i cant get a output signal as it says. I checked with meter, everytime it shows defferent constantan volt on output.

Did you follow the adjustment procedure? In a low noise environment, adjust RV2 until the output is high (3.5v), then adjust the other way until goes to near 0v. If adjusting RV2 does not change the voltage from 3.5 to 0v then the circuit is improperly assembled.

Can you tell me what is output volt, like is it +v or -v ?

The output will be anywhere from 0v to about 3.5v, depending upon the positions of RV1, RV2 and the sound level.

I dont understand the Third part of circuit. the third transistor is npn and the output is not on right place, i mean pin C of the trasistor should be the output...."

You are mistaken. The output is correct. It is an emitter follower. The voltage at the emitter will "follow" the voltage at the base.

Attached is a diagram that breaks the circuit into 3 stages. Build stage 2 and 3 only. After it is done, put your meter on the output. Then adjust RV2 and see if the voltage changes from 0v to 3.5 v. If it does not, then you have misplaced a component, have something backwards, used the wrong value component, or wired something incorrectly. Once you have this working then build stage 1 and connect it to stage 2. Adjust RV1 for best operation.

You may want to change C4 to a smaller value for testing. When there is sound, C4 will charge and keep the output HIGH for about 1/2 second even after the sound stops. A smaller value will allow the output to reset to 0v faster after the sound event ends. I would suggest 100nf.

If you still cannot get it working, then you will need to take a close up and clear photo of your breadboard and post it here on the forum. The photo should be taken from directly above the breadboard so that everything can be seen. If you do not provide a photo then you will likely not get any more help as there is nothing more anyone can do without it.

 

[shah_siddiquee]

@ Goeytex . thanks

Thanks mate for your nice suggestion. I will try one more time as you said. Actually i tried 4 times to build it. But i failed. So i thought is the diagram ok? Thats why i asked if anyone made this circuit. Now i got it, it must be my mistake. Many thanks.

 

[shah_siddiquee]

my sound detector circuit works

@ goetex, thanks mate its working now, but i had to made some changes though. I tried to build 2nd and third stage of the circuit as you suggested me. But it still didnot work. But it helped me to connect all parts saperately. So i tried to build a normal amplifire circuit', like i put resistor with base, possetive collector and negetive emmitor and then i put all other parts checking one after another. And then I GOT THE PROBLEM OF THE CIRCUIT. IN SECOND STAGE I REMOVED 47K VR AND 220K RESISTOR . ALSO I INCREASE VALUE OF RV1 TO 10K. REST OF THE PARTS ARE OK AND SAME PLACE. THEN ITS WORKED. I THINK THE SCHELATIC WAS WRONG. thanks for your help. And am sorry i couldnt provide any picture as i am using mobile to read and write.

 

[AllyCat]

I REMOVED 47K VR AND 220K RESISTOR . ALSO I INCREASE VALUE OF RV1 TO 10K. ..... I THINK THE SCHELATIC WAS WRONG.

Hi,

There is nothing wrong with the schematic diagram, although I personally dislike circuits which may appear not to work at all if a bias pot (RV2, 47k) is incorrectly set. But equally it "won't work" if the "gain" pot (RV1) is set at its "zero" end (Vcc, at the top). Changing RV1 from 4k7 to 10k should make no significant difference, so maybe your 4k7 pot was faulty.

However, removing the 47k pot and the 220k, removes all the "dc bias" from transistor TR2 so it should then NOT work. My guess is that either your C3 (470nF, dc blocking, ac coupling) capacitor is faulty/incorrectly fitted, or transistor Q2 is faulty or fitted backwards/incorrectly.

Cheers, Alan.

 

[Goeytex]

And then I GOT THE PROBLEM OF THE CIRCUIT. IN SECOND STAGE I REMOVED 47K VR AND 220K RESISTOR . ALSO I INCREASE VALUE OF RV1 TO 10K. REST OF THE PARTS ARE OK AND SAME PLACE. THEN ITS WORKED. I THINK THE SCHELATIC WAS WRONG.

There is nothing wrong with the schematic. It works fine as drawn.

RV2 and R5 act to bias PNP transistor Q2. By removing them Q2 has no DC bias and will not work properly. My guess is that you have at least one of the transistors placed backwards in the circuit.

With the BC558 and BC548, when facing the flat side and with the leads pointing down, the emitter is on the right hand side. This is a reversed layout from a 2N3904 and a 2N3906 where the emitter would be on the left. Attached are Pinout diagrams.

Most folks will find a way to post a photo when necessary. Sorry, but I am not buying your excuse.

 

[austfox]

Just breadboarded this circuit as I thought it would be good to experiment with sound input into a Picaxe. Can confirm it works fine - a little over 1v output for normal speech, and around 3v for a hand-clap.

Might solder this circuit onto a Protostack board to keep for future experiments.

Steven.

 

[shah_siddiquee]

The picaxe sound detector working.

Thanks guys my sount detector works perfectly. You were right. I was wrong. It wasnt that the way i made. I dont know what was the mistake i made seven times. I just puted all the parts again same way and it works. The transistor pin config also same. Anyway the amplify is not enough for my project though. Can anyone give me more sensetive sound detector circuit diagram please.

 

[westaust55]

@Shah,

have YOU tried a Google search for such circuits for yourself ?

I do not know what the sensitivity/gain of the Rev Ed circuit is so hard to know what will be more sensitive.
You do not indicate whether you need something 2 or 10 time more sensitive so it become rather subjective.

here is one option:
Littlebird Electronics and Jayar areselling the Freetronics microphone sound input pre-assembled module which has a Sensitivity of -40dB typical.


This requires an analogue input and use of the READADC command generally as per the Rev Ed circuit.
Freetronics Sound module: http://www.freetronics.com/collections/modules/products/microphone-sound-input-module
Schematic: http://cdn.shopify.com/s/files/1/0045/8932/files/MIC_MicrophoneSoundModule.pdf?100735
Jaycar web page: http://www.jaycar.com.au/productView.asp?ID=XC4236
Littlebird Elecronics: http://littlebirdelectronics.com/search?type=product&q=sound+input
These are Australian based outlets but you may find a Freetronics dealer closer to you in the UK.

Seemingly sold out at Freetronics at the moment but if you check with Jaycar, some of their stores may still have them in stock – mind you from some near recent experience don’t rely upon the Jaycar database being correct (one reason being some types are stealing parts and the computer still thinks they are on the shelf months later so no re-order occurs).

As a fully assembled module should be easier for you to get working.


EDIT: in the UK try: http://www.coolcomponents.co.uk/catalog/

 

[ValueAdd]

Knowing exactly how you want to use the sound senor would be helpful for folks trying to help.
Are you trying to detect just short sharp clap and knock type sounds or also quiet spoken voices?


Here are some links to sound sensor circuit that I have NOT checked/tested/verified but most do include a schematic on the website:
http://www.dfrobot.com/index.php?route=product/product&product_id=83
http://www.parallax.com/tabid/768/productid/614/default.aspx

http://www.seeedstudio.com/depot/-p-752.html?cPath=144_148
and
http://www.seeedstudio.com/wiki/index.php?title=Twig_-_Sound_Sensor


Don’t be put off by the fact that most sensors suggest they are designed for a different microcontroller. They will also work with PICAXE chips.

 

[shah_siddiquee]

i need circuit diagram to build by my self

Thanks guys. I got this modules allready. But i want to build by myself. I need 200 gain sound sensor for my robot which can react from other room. I found some scematics on google but i dont know which circuit will give that performance.

 

[Goeytex]

Thanks guys. I got this modules allready. But i want to build by myself. I need 200 gain sound sensor for my robot which can react from other room. I found some scematics on google but i dont know which circuit will give that performance.

Then it seems like it is time for you to do some studying and experimenting. We can't do it all for you. A quad Op-Amp with a few resistors and capacitors can do what you want.

I suggest you you start here: >>>> http://www.electronics-tutorials.ws/opamp/opamp_1.html

You may also want to view this ====> http://www.analog.com/library/analogdialogue/archives/39-05/Web_Ch6_final_I.pdf

 

[Paix]

Thanks guys. But i want to build by myself.

I am sure that we quite understand.

Increased sensitivity perhaps requires a background of profound silence if not to be perceived as interference. Proving that double entendre is alive and well, even if I can't spell lit correctly

I suspect that extraneous noise pickup from your environment could make for some interesting results and may suggest that further audio processing is required, such that the amplitude is sliced and the frequency components are used instead, with attendant complexity. In the meantime, Goeytex offers good advice and op amp datasheets also offer thumbnail circuits for a variety of typical functions that you can pour over and use the building blocks directly or as an aid to greater understanding. http://www.ti.com/lit/ds/symlink/lm124-n.pdf Page 10 and beyond is probably where you might want to start looking.

Note that figure 26 the Voltage follower/Buffer is as simple as it gets and is good for securing a signal and making it available for further processing, without loading the signal source itself. Enjoy! Your breadboard is your friend.

 

[russbow]

@shah_siddiquee .You haven't actually told us what you want to do!

Is it to get a "reaction" to a sudden noise - the circuit you have tried is perfect for that.

Or are you wanting audio playback. Then search for LM386.

Or are you looking for voice recognition - not, i suggest, a beginner's project.

What do you mean by "I need 200 gain sound sensor for my robot which can react from other room"

You say you have found circuits on Google, but you don't know which will give the performance.

Nor do we because you havn't given us the links.

 

[shah_siddiquee]

@ Russbow. my project ditails.

At first i tell you what is my intention. I am making such robot which will react when i call or make a specific sound. Even when its in other room. I need four sound sensor circuit so i can put four side of robot, like, left, right, front and back. and when i call it or make a sound it will measure the sound level and calculate which way the sound coming from most. And will forward the strongest way sound comes. Now friend i hope you can guess what i am trying to do with the sound sensor. Please tell me your opinion and suggestion about it. If you know any better way of making this please let me know. Thanks

 

[shah_siddiquee]

thanks to paix and goeytex.

Thanks guys i saw this links. Now i am thinking i will try one of this modules schematics by my own. You know, you posted one link which is made by LM358 i am gonna try this. I orderd that IC. I hope it will work. Thanks

 

[MikeAusP]

At first i tell you what is my intention. I am making such robot which will react when i call or make a specific sound. Even when its in other room. I need four sound sensor circuit so i can put four side of robot, like, left, right, front and back. and when i call it or make a sound it will measure the sound level and calculate which way the sound coming from most. And will forward the strongest way sound comes. Now friend i hope you can guess what i am trying to do with the sound sensor. Please tell me your opinion and suggestion about it. If you know any better way of making this please let me know. Thanks

Firstly, you will need to use Directional or Cardioid Microphones because normal microphones are omnidirectional and so 2 or 3 microphones will pick up exactly the same level for sound coming from one direction.

Secondly, reverberation of sound within a house will mean that the loudest sound will not necessarily come for the source, but from a reflection off a wall or furniture. Be prepared for it to make many changes in direction before it heads in the correct direction, so you will also need repetitive calls.

Thirdly, it will have trouble differentiating your call from noise from quieter sources which are much closer - it may continually head towards the fan in your PC ! I think you will have to use a whistle - then use narrow filters to ensure it only hears the frequency of the whistle.

 

[shah_siddiquee]

i have to do online search for these microphones

You got my point perfectly. Adjactly same thing i was thinking what you said In your second pera. But i dont really know what will happen because i didnt make it yet.

 

[bfgstew]

Out of curiosity, I had another go at this circuit, as it didn't work for me first time, but this time it works absolutely perfectly!!!!
But I did come across a problem, Q2 is shown incorrectly on the drawing, I think, (I can't add a drawing as works PC will not allow it). But the arrow from the Collector to Base is incorrect according to the pinouts I have seen, it should be from Emitter to Base, so I just turned the transistor 180 degrees and now works perfectly.
I may be wrong, but later tonight I will add datasheets and drawings if people are interested.
Stewart

 

[AllyCat]

Hi,

Hi,

Yes, the arrow (always) shows the emitter-base junction, but the pnp emitter goes towards the supply rail (so the diagrams in #2 and #8 are indeed correct).

However, as Goeytex pointed out in #12, the relevant BC... series of transistors have the opposite pin sequence to the otherwise similar 2N.... family. And of course some transistors have the collector in the middle!

Cheers, Alan.

 

[bfgstew]

My mistake, the schematic is correct, I just had an odd BC558B with pinout back to front. Good job I had a scope to test and check input and outputs!

 

[shah_siddiquee]

the circuit diagram is perfectly allright

Same here mate. I tried this schematic on breadboard 9 times and on my 10th time i made it. This circuit is better than the other ready made sound sensor modules in market. But i dont know why it took so long to me.

 

[westaust55]

I just had an odd BC558B with pinout back to front.

Not another Ebay purchase I trust?