I recently got the DSO Nano V3 (firmware 4.21)… I have a IC555 circuit (astable) as I was hoping to show the sq wave from this. I have not been able to. Any suggestions? I have the clip probes on the 555 pin 3 and the other probe on ground…
Also, I could certainly use a user guide on this thing. I have friend who may also purchase this, but ONLY if I can show how this thing works period.
I was able to show the duty cycle from one of arduino’s PWM pin… but haven’t a clue how to show the freq from the IC555
Do know approximately what frequency the 555 is generating? You should choose a time base on the oscilloscope that gives you some tens of signal periods on the screen. Are you sure the 555 is oscillating at all?
the lower right hand of the screen shows frqn122Hz
I have the trigger set to Auto
what I get is one sq wave cycle that just moves along the screen (blue line)…
white line is a flat line.
under the “Ex” menu I have “-Inp” which I’m to take is just the input wave data.
I was hoping to show multiple cycles.
Also, when I disconnect the probes completely, the above just still happens… so either this has a buffer or the single sq wave cycle is not the pulse from the 555
yes I probably ought to read more on oscilloscopes… but since the 555 is a basic IC, was hoping I could at least see it.
The “-inp” mode shows the input waveform inverted, and in purple. You can turn it off by going to EX > ext refn > off.
I’d suggest using an LED or some other indication on the 555’s output first, to make sure you actually are getting a signal. You can also test the scope on it’s built in frequency generator.
However, you say you get a single square wave moving along the bottom? It sounds like you are picking up a signal, it’s just not syncing with your trigger. Adjust the y range until the voltage scale matches what you’re expecting, if you have a 5 volt signal, 1 v/div is usually a good choice.
If you get the height of the signal displaying nicely, you can then adjust the trigger level (green line) up or down so it’s in the middle of your signal’s amplitude. Rising or falling edge triggering will determine which side of the input signal is synced with the trigger line.
You also have to play around with the time settings a bit too. Anything too far out of range will cause the signal appear in unexpected ways. For example, a high frequency signal displayed at a large time/div would shows as a flat line, instead of the “thick” band that it should really be displayed as.
Basically, you just have to play around with it (with a known good signal), and you’ll figure it out…
