Setting the function generator's frequency
gpgordon
Posts: 1
Hi all,
Been pleased with the propscope overall, but I'm having an issue specifying an exact frequency for the function generator feature.· Not sure if this is a limitation of the GUI or if it also reflects a hardware issue.
I am trying to make some fairly tight measurements of a 200kHz sonar transducer's response.· Since the transducer is essentially a piezoelectric device, it changes rapidly in behavior near the series and parallel resonant frequencies.· I was hoping to use small frequency steps (i.e. 50 - 100Hz)in the vicinity of 200kHz but find that the GUI rounds off the value back to 199k, 200k, or 201k.
Is there a way to specify a more exact frequency such as 199950Hz?· Given the nature of the propScope's timing, I would have guessed this to be possible?· Am I missing anything obvious?
v/r,
Glen Gordon
Been pleased with the propscope overall, but I'm having an issue specifying an exact frequency for the function generator feature.· Not sure if this is a limitation of the GUI or if it also reflects a hardware issue.
I am trying to make some fairly tight measurements of a 200kHz sonar transducer's response.· Since the transducer is essentially a piezoelectric device, it changes rapidly in behavior near the series and parallel resonant frequencies.· I was hoping to use small frequency steps (i.e. 50 - 100Hz)in the vicinity of 200kHz but find that the GUI rounds off the value back to 199k, 200k, or 201k.
Is there a way to specify a more exact frequency such as 199950Hz?· Given the nature of the propScope's timing, I would have guessed this to be possible?· Am I missing anything obvious?
v/r,
Glen Gordon
819 x 690 - 213K
Comments
I'm 99% sure that the round-off happens at display time- so the PropScope is still generating the exact frequency you want- down to .1 of a hz. So, feel free to output a 1,234,567.8Hz sine wave...
I'll look into fixing the display issue.
Hanno
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Co-author of the official Propeller Guide- available at Amazon
Developer of ViewPort, the premier visual debugger for the Propeller (read the review here, thread here),
12Blocks, the block-based programming environment (thread here)
and PropScope, the multi-function USB oscilloscope/function generator/logic analyzer