Oscilloscope help

[Megahertz]

Hi, I am trying to replicate a waveform. I can see it on my oscilloscope, but I can't get the exact data I need just by looking at it as it is changing very fast. These are pulses from a uC of different periods. I tried the datalogging function on my scope, but I am unable to understand the data. Can someone please help me understand the information which is logged by my scope. I have attached the PDF of the logged data.

The pulses are not continues and only appear for few seconds and then there is a period of no signal and then again the pulses start.

If you want to watch how the pulses appear, I have also uploaded the video.


Thanks

[dhouston]

It's very difficult to judge given that you have not synced your scope but they appear to be RF or IR signals with a fairly wide start pulse followed by a series of shorter pulses which contain the data.

Perhaps you could get a better picture using your soundcard to record the signal. That gives you something you can playback in an editor (e.g. GoldWave). See http://davehouston.org/learn.htm

[Megahertz]

This is neither an IR nor an RF signal. I put the scope directly to the uC pin outputting this signal. This is the waveform which creates an alarm like noise when fed to the base of the npn transistor on which a coil and a piezo buzzer are connected on the collector side in parallel to each other. But since the pulses are changing so quick, visually I can only make out that the minimum pulse is 150uS and MAX is 250uS. These pulses are increasing from 150 to 250 in some number of steps. I tried replicating this in equal 10 increments of 10uS but it does not match as it does not produce the same sound effect. So I logged the data, but need someone to explain me what the two long rows mean. To me it seems some values (between 150uS - 250uS) are repeated more than once, I am hoping the correct interpretation of the logged data will make it more clear.

[kellyseye]

Looks like 'swept' signal.

The square wave frequency is being increased (swept) from x(Hz) to y(Hz) by a modulating waveform. It 'looks' like it's sweeping from around 2kHz to 3kHz by a low (250Hz???) signal.

Configure an output to a 2kHz square wave and arrange for it to increase by 4Hz every 4uS until it reaches 3kHz then repeat.

[Megahertz]

Hello kellyseye, I tried the following, but no sucess:

while 1
		Pulsout PortC.0,25
@	NOP
@	NOP
@	NOP
@	NOP
		Pulsout PortC.0,24
@	NOP
@	NOP
@	NOP
@	NOP
		Pulsout PortC.0,23 
@	NOP
@	NOP
@	NOP
@	NOP
		Pulsout PortC.0,22
@	NOP
@	NOP
@	NOP
@	NOP		
		Pulsout PortC.0,20 
@	NOP
@	NOP
@	NOP
@	NOP
		Pulsout PortC.0,19
@	NOP
@	NOP
@	NOP
@	NOP
		Pulsout PortC.0,18 
@	NOP
@	NOP
@	NOP
@	NOP
		Pulsout PortC.0,17
@	NOP
@	NOP
@	NOP
@	NOP
		Pulsout PortC.0,16 
@	NOP
@	NOP
@	NOP
@	NOP
		Pulsout PortC.0,15
@	NOP
@	NOP
@	NOP
@	NOP

Wend

[Megahertz]

Here I have recorded the sound produced by the buzzer. Please rename the attachment to "Memo.m4a" from ".pdf" as I could not upload it in its original format.