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I'm generating pulses on ATmega32 and I need to see the pulse wave in the oscilloscope in order to check its frequency. So I connect the pin to the oscilloscope channel and the pin blinks on and off but the oscilloscope doesn't show the wave... what am I doing wrong? Is there any other way to measure the frequency?

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    \$\begingroup\$ Did you set properly the oscilloscope to show the waveform? \$\endgroup\$ – clabacchio Nov 11 '12 at 16:43
  • \$\begingroup\$ You could just hook the pin up to a voltmeter and manually time it. I don't have it open, but I recall you select the graph window you want and then hit space to simulate. Make sure you set the time in the window to something suitable so it actually captures your data. \$\endgroup\$ – Josh Nov 13 '12 at 17:36
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If you could see the LED going on and off, the waveform is changing much to slow for the scope to be useful. Try the frequency counter, and set it to measure the time period instead of the frequency for such slow changes.

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  • \$\begingroup\$ This is only somewhat true, and then only for analog oscilloscopes. \$\endgroup\$ – Connor Wolf Jun 6 '13 at 3:27
  • \$\begingroup\$ @ConnorWolf I think the question refers to the oscilloscope virtual instrument built into Proteus, not a physical instrument. \$\endgroup\$ – Anindo Ghosh Jun 6 '13 at 11:31
  • \$\begingroup\$ @AnindoGhosh - It's a virtual oscilloscope, and you can't set the horizontal sweep to a low value? \$\endgroup\$ – Connor Wolf Jun 6 '13 at 19:57
  • \$\begingroup\$ @ConnorWolf The best it can do is 0.2 seconds. No idea what frequency OP is generating. The Counter-Timer virtual instrument might be more appropriate. \$\endgroup\$ – Anindo Ghosh Jun 6 '13 at 20:07
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Unfortunately sometimes the oscilloscope behaves strangely and doesn't show the waveform for a while.

One alternative is to use the frequency meter assuming that the frequency of the signal you want to measure is constant. The frequency meter needs 1 second of simulation time in order to show a result and is refreshed every second.

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The second method which can show the result almost instantly (unlike the frequency meter) is to use the digital graph, place a voltage probe in the schematic and add it to the digital graph, then you can use the snap on edge function of the cursor to see the duration of the signal you are interested in (shown in the lower left corner of the graph).

enter image description here

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