MIDI MESSAGES

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Woody
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Joined: Mon Feb 05, 2018 2:15 pm

MIDI MESSAGES

Post by Woody » Thu Mar 22, 2018 1:07 pm

Hi,

I'm currently working on a project where I am looking at MIDI messages.
I am successfully seeing the data and the decoder is working fine.
The data is transmitted in 3 X 8bit packets. the scope sees these and collects them into a buffer.
The problem I am having is when the buffers are transmitted close to each other I am losing data.
I can see the the first buffer but not the second.
If I alter the settings I can see the two buffers being transmitted but they have poor definition and are not decoded correctly.
I have attached 2 traces, the first shows correctly decoded buffer the second shows 2 buffers transmitted with a 80ms delay between.

Any ideas ?

Woody
Attachments
2_BUFFERS.psdata
2 buffers no detail
(8.68 KiB) Downloaded 137 times
1_TRACE_DECODE.psdata
single buffer
(8.78 KiB) Downloaded 124 times

Martyn
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Location: St. Neots

Re: MIDI MESSAGES

Post by Martyn » Thu Mar 22, 2018 2:04 pm

I would try increasing the requested number of samples at the top of the screen to as high as possible. Set it to 2GS and it will use the highest possible that the device can support, and make sure that slow sample transition (Tools->Preferences->Sampling) is set to 100ms/div so the trace is drawn live scrolling from the left.
Martyn
Technical Support Manager

Woody
Newbie
Posts: 0
Joined: Mon Feb 05, 2018 2:15 pm

Re: MIDI MESSAGES

Post by Woody » Fri Mar 23, 2018 11:23 am

Thanks Martin,

That's getting the data now.
I tried increasing the number of samples but not the transition time.

Regards
Woody

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