Post by thread:Making a ticking sound

I have an application where I need to make a short ticking sound, about 1 per second or so. It needs to be heard from as far as 10' away, but not much louder. It would be really nice if it was simple and within 5 volts. I screwed around with a cheap speaker out of a PC, where I put it between 5V and the collector of a PN2222, then switched the transistor every second by toggling the pin on the PIC (16C73). It had the right sound but wasn't loud enough. Does any one have a device or circuit that work for this? Ryan

This is the first problem. You are not exciting correctly the speaker. First of all, applying DC to a speaker will create just a small and single air pushing, like a "click", not enough to generate a loud signal, except if you have a large speaker with a large "air pump" cone. Small speakers works better by creating a constant air oscillation. Second, by applying 5V at one moment, makes the speaker cone move in one direction, then applying "nothing" at next second, makes the speaker cone just returns to its resting mechanical position, slowly by its own "spring" action. If you apply a single capacitor, resistor and two transistors, you will have a nice Push-Pull configuration. By this way you would push and pull the speaker cone to opposite directions every time you switch levels... Instead of just switching the port pin level, try to send a burst of audible frequency, lets say switch the port pin state 50 times using a pulse period of 0.5ms, it would generate a 1kHz tone during 25ms, fast and pretty good. Trying different pulse period and pulse quantity, you could find out a loud setup. +5Vdc | | C .---------B NPN 2N2222 | E | | _____ 1kOhms | | + \ / PIC port pin ----RRRR-----o o----||----SPEAKER---. | | 100µF | | | | | E PNP 2N2907 gnd '---------B C | | gnd Little more power? +5Vdc +5Vdc | | | | | C R .---------B NPN 2N2222 1 R | E kOhms R | | _____ | | | + \ / | | o----||----SPEAKER---. o--------o | 100µF | | | | | PIC 5kOhms C | E PNP 2N2907 gnd Port ---RRRR----B '---------B Pin E C | NPN 2N2222 | | | gnd gnd There are the inverted possibility, using the PNP to +5V, and the NPN to ground, but it requires more components, and you don't need it now. Wagner Ryan Miller wrote: {Quote hidden}> > I have an application where I need to make a short ticking > sound, about 1 per second or so. It needs to be heard from > as far as 10' away, but not much louder. It would be really > nice if it was simple and within 5 volts. I screwed around > with a cheap speaker out of a PC, where I put it between 5V > and the collector of a PN2222, then switched the transistor > every second by toggling the pin on the PIC (16C73). It had > the right sound but wasn't loud enough. Does any one have a > device or circuit that work for this? > > Ryan

Get a piezo buzzer (not speaker) from Radio Shack. Operates off of 5 volts and 20 ma. Fairly loud (the buzzer). I use it as a low battery warning on my robots. Dan {Quote hidden}> I have an application where I need to make a short ticking > sound, about 1 per second or so. It needs to be heard from > as far as 10' away, but not much louder. It would be really > nice if it was simple and within 5 volts. I screwed around > with a cheap speaker out of a PC, where I put it between 5V > and the collector of a PN2222, then switched the transistor > every second by toggling the pin on the PIC (16C73). It had > the right sound but wasn't loud enough. Does any one have a > device or circuit that work for this? > > Ryan

I have with success (after it was suggested on the Piclist) connected a piezo device between two port pins to get an effective 10 V swing. RB0 -----piezo speaker------RB1 Start off with RB0 = 0 V, RB1 = 5 V. Now switch them to RB0 = 5 V, RB1 = 0. Do this about 4000 times a second for a nice noise. A good idea is to play around with the frequency - most piezo speakers have a narrow frequency band in which they are really loud. I cannot remember what the verdict was on whether it is necessary to include series resistors... Cheers Roland {Original Message removed}

Hi, as a short idea: after toggling the PIN you should re-toggle it after ... say 1 msec. IMHO it enhances the effect and will not load the speaker and the transistor unnecessary. Regards, Imre On Wed, 26 Jan 2000, Ryan Miller wrote: {Quote hidden}> I have an application where I need to make a short ticking > sound, about 1 per second or so. It needs to be heard from > as far as 10' away, but not much louder. It would be really > nice if it was simple and within 5 volts. I screwed around > with a cheap speaker out of a PC, where I put it between 5V > and the collector of a PN2222, then switched the transistor > every second by toggling the pin on the PIC (16C73). It had > the right sound but wasn't loud enough. Does any one have a > device or circuit that work for this? > > Ryan > >

> -----Original Message----- > From: Ryan Miller <spam_OUTfrmillerTakeThisOuTPLIX.COM> > To: .....PICLISTKILLspam@spam@MITVMA.MIT.EDU <PICLISTKILLspamMITVMA.MIT.EDU> > Date: Wednesday, January 26, 2000 3:03 PM > Subject: Making a ticking sound > > >I have an application where I need to make a short ticking > >sound, about 1 per second or so. It needs to be heard from > >as far as 10' away, but not much louder. Need Sounds from PICmicros? ; SOUND port, pin, frequency, duration ; Generates squarewave tones (notes) of the specified frequency and ; duration. This demonstration program shows how to use lookup tables to ; play tunes or effects from data stored in program memory. found at: http://www.dontronics.com/convert2.html#sound Basic Stamp Compatible PIC Source Book/Disk On-Line Version Free! Now converted to MicroChip Code, still available in Parallax Code. A collection of ready-to-use assembly language routines based on the instruction set of the BASIC Stamp ¨ single-board computer by Scott Edwards Electronics. Includes useful schematics. For MicroChip code: http://www.dontronics.com/convert.html For Parallax code: http://www.dontronics.com/see.html Don McKenzie .....donKILLspam.....dontronics.com http://www.dontronics.com World's Largest Range of Atmel/AVR and PICmicro Hardware and Software. Free Basic Compiler and Programmer http://www.dontronics.com/runavr.html

Roland Andrag wrote: > >I have with success (after it was suggested on the Piclist) connected a >piezo device between two port pins to get an effective 10 V swing. > >RB0 -----piezo speaker------RB1 > >Start off with RB0 = 0 V, RB1 = 5 V. Now switch them to RB0 = 5 V, RB1 = 0. >Do this about 4000 times a second for a nice noise. A good idea is to play >around with the frequency - most piezo speakers have a narrow frequency band >in which they are really loud. > >I cannot remember what the verdict was on whether it is necessary to include >series resistors... > Roland: For a 'purer tone' you might want to try pulsing your piezo with a duty cycle of 2/3 (ie +ve for 2t, off for t, -ve for 2t and off for t). I believe if you do a Fourier analysis of this waveform, you'll find there are no 3rd and 9th harmonics, etc.(as well as no even ones due to the symmetry) giving you a cleaner sine wave than you would have with the 50% square wave that you're proposing. For experimental use, you'd likely get away with no series resistor, but I wouldn't do it. The piezo element is one big capacitor that you're charging/discharging so to limit the current add some resistance. ~1K is a good ballpark to try. Jim Nagy Elm Electronics ICs for Experimenters http://www.elmelectronics.com/

A tick (or click) is a short burst of high frequency audible tone. Play around with the duration and frequency until it gives you the effect you want. Tom Mariner > -----Original Message----- > From: Ryan Miller <EraseMEfrmillerspam_OUTTakeThisOuTPLIX.COM> > To: PICLISTspam_OUTMITVMA.MIT.EDU <@spam@PICLISTKILLspamMITVMA.MIT.EDU> > Date: Wednesday, January 26, 2000 3:03 PM > Subject: Making a ticking sound > > >I have an application where I need to make a short ticking > >sound, about 1 per second or so. It needs to be heard from > >as far as 10' away, but not much louder.