Scope capabilities and limitations

AlWared

Hello Bela users,

As I don't own an oscilloscope, I'm considering using Bela scope for small audio projects. I don't have Bela yet and I'm wondering about the scope capabilities compared to a pro digital oscilloscope.
Is it possible to use it above audio frequencies ? What is the frequency limitation ?
Would it be possible to use a probe ? Or how would you optimally display external signals ?
How many input channels could I get from external pins ?

The idea is to get a scope and an instrument all in one as you can guess. I'll buy a real scope then.

giuliomoro

AlWared Is it possible to use it above audio frequencies ? What is the frequency limitation ?

The audio input/output of Bela is at 44.1kHz. Analog (DC-coupled) I/O is at 22.05kHz for 8 channels or up to 88.2kHz for 2 channels. These set the scope's bandwidth with respect to real-world signals.

AlWared Would it be possible to use a probe ? Or how would you optimally display external signals ?

The I/Os are available as socket headers with 2.54mm spacing. Connecting a regular scope probe will require you to make a custom connector.

AlWared How many input channels could I get from external pins ?

See above and https://github.com/BelaPlatform/Bela/wiki/Hardware-explained . Note the voltage input ranges. Supplying voltages outside those ranges may permanently damage the board.

AlWared

Ok so that's usable for audio rate with a side circuitry such as voltage limiter/divider. And maximum use would be 88.2KHz 2 channels.
Thanks

airnocker

giuliomoro, are there any plans to add XY vector displaying of two channels to the in-browser oscilloscope capability?

giuliomoro

I wish! We are looking at a longer term project to remove the existing scope component and replace it with something more modern and better featured. Have you seen any around that could be a good plug-and-play replacement?

airnocker

Thanks for your response.
I gave a quick 'Google' after your reply and question. Github has a few listed that may be worth a look as does Sourceforge.net.

I'm fairly new to Bela, its IDE, the Arduino IDE, the Teensy IDE and trying to learn this stuff, having come from a more comfortable and familiar world of ye ol' 6500 assembler. So, I doubt there is much I could contribute beyond cheerleading. ;-)