Very likely, I'm doing something wrong or the software is designed badly.
I have OSC482 from Loto Instruments. Seemed like a decent scope for occasional experiments.
Now I'm trying to debug a practical problem (and learn as I go). There is a device sending MIDI protocol bytes. Essentially it's UART start-8-stop at 31250 baud rate.
The device is sending a byte 0xFE about every second.
I connected my scope to the optocoupler that receives the data. I could see something coming in, yay. But the data flashes by too fast. That's what the triggers are for, right? I can set a trigger, it will pause the input and then I preview it zooming and scrolling left & right. I had to fiddle a bit with the time division settings because the osc disables the trigger for some time values. Finally, I managed to enable the trigger, move its handle to the expected voltage (around 2V), set it to trigger on fall-off (because UART is high by default) and hit Single button to capture a packet.
I see it has been captured in the cache - there is a peak in the preview. But I cannot select it in any way to investigate in the main view! There seems to be no way to scroll the frozen view back in time nor any way to activate those cached frames and inspect them.
I know that OSC482 has software and not hardware trigger, so it can be inaccurate. But this time it seems mostly a software problem. I had to hit Single like a thousand times to finally get lucky and get a byte in the main view. At the same time, I see it did capture a byte in every small preview rectangle, I just cannot access them somehow.
Then I thought it would be easier to record a fragment and then inspect it... no luck, the recording seems to have the same problem - I cannot pause it and scroll to wherever I want (or scrolling could be hidden somewhere).
I also tried out UART decoding feature, setting all the parameters as needed (31250, start, 8 bytes, stop, no parity), but it did not yield any bytes. Maybe this function is not supposed to work with the analog probe.
This makes me consider upgrading to a better oscilloscope, but I'm not sure if it's worth it. OSC482 seems to be totally enough for me with its hardware specs. I wish there was alternative software for OSC482.
I don't have a place for a full-size scope and also I'm visually handicapped, so computer scopes are much more convenient for me. Analog Discovery 2 or PicoScope seem to be the safest choices, but they are a bit too pricey though.
Still, I'm wondering, how would the same scenario work with AD2 or PicoScope? Do other scopes have the ability to easily zoom / scroll the view back&forward in time after capturing a triggered signal (assuming the signal was captured with proper resolution)?