Test and Measurement Forum

MIDI MESSAGES

Post any questions you may have about our current range of oscilloscopes

MIDI MESSAGES

Postby 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 73 times
1_TRACE_DECODE.psdata
single buffer
(8.78 KiB) Downloaded 70 times
Woody
Newbie
 
Posts: 0
Joined: Mon Feb 05, 2018 2:15 pm

Re: MIDI MESSAGES

Postby 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
Martyn
Site Admin
Site Admin
 
Posts: 3041
Joined: Fri Jun 10, 2011 8:15 am
Location: St. Neots

Re: MIDI MESSAGES

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


Return to USB PC Oscilloscopes

Who is online

Users browsing this forum: No registered users and 0 guests