Some questions on MIDI test - Electronic Circuits Projects Diagrams Free

nicholastyc · 29th May 2008, 03:20 PM

Hi,

i have some question on MIDI test, I have a midi out from keyboard, i would like to connect it to a MIDI synthethiser and go to the Amp and speakers.
Please correct me if i m wrong and give me some input.

1, i would like to know the MIDI out pin config, pin 1,3 are NC, pin 2 is GND, pin4 current source, pin5 current sink, are they correct?
2, wat kind of output waveform do i expect? i tested on a LED, when the key is pressed the LED blink once but the light is very dim. do i getting the correct signal?the signal seem to be quite low.
3, i was trying to use a 4N32 opto coupler to isolate the signal, but failed, did not receive any signal at the output, the output is going to my MIDI synth, i checked on internet, found that 6N138 time rise/fall is faster, i ordered it. stil waiting... just curious on...the output signal i can get?
FYI, i tested on a LED, the LED keep on, i should get a blink on the LED to the midi syth but i did not get the signal, so the speaker don have any sound output.
i am using the ATMEL, ATSAM2195 3.3V fixed supply circuit design provided on the datasheet as my MIDI synth.

Thanks for help...is my design has any problem? the speakers don work...

**Nigel Goodwin** · 29th May 2008, 03:45 PM

The data is pretty standard RS232 serial data, at a specific (non-standard) baud rate, it's pretty easy to do - there are loads of PIC examples on the net, and presumably many AVR ones as well?.

An LED is no use to monitor the data, use an oscilloscope.

nicholastyc · 29th May 2008, 04:21 PM

Hi Nigel, u r a super moderator..! thanks again.
i m not using the PIC...
i am using an ATSAM2195 chip from Atmel.
i tried to check on the oscilloscope...the signal is very unstable from the MIDI out of the keyboard. and i found the LED test to the output, HINTON INSTRUMENTS: Professional MIDI Guide

i find the signal is similar to what it was explained on the page.

i will try to test it on a 6N138 opto isolator to check at the Vo .

Anyone who have the experience on MIDI..please feel free to give advise.
Thank you... =)

nicholastyc · 3rd June 2008, 03:40 PM

Hi,
i need some helps..i tested on the 6N138 opto isolator, the signal seem right. after i sent the signal to the ATSAM2195 board, the output seem to be quite alots of noises. so i could not hear any sound from the speaker..

please help on me..urgent ! been working on this few days...

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29th May 2008, 03:20 PM	(permalink)
nicholastyc	Some questions on MIDI test Hi, i have some question on MIDI test, I have a midi out from keyboard, i would like to connect it to a MIDI synthethiser and go to the Amp and speakers. Please correct me if i m wrong and give me some input. 1, i would like to know the MIDI out pin config, pin 1,3 are NC, pin 2 is GND, pin4 current source, pin5 current sink, are they correct? 2, wat kind of output waveform do i expect? i tested on a LED, when the key is pressed the LED blink once but the light is very dim. do i getting the correct signal?the signal seem to be quite low. 3, i was trying to use a 4N32 opto coupler to isolate the signal, but failed, did not receive any signal at the output, the output is going to my MIDI synth, i checked on internet, found that 6N138 time rise/fall is faster, i ordered it. stil waiting... just curious on...the output signal i can get? FYI, i tested on a LED, the LED keep on, i should get a blink on the LED to the midi syth but i did not get the signal, so the speaker don have any sound output. i am using the ATMEL, ATSAM2195 3.3V fixed supply circuit design provided on the datasheet as my MIDI synth. Thanks for help...is my design has any problem? the speakers don work...

29th May 2008, 03:45 PM	(permalink)
Nigel Goodwin	The data is pretty standard RS232 serial data, at a specific (non-standard) baud rate, it's pretty easy to do - there are loads of PIC examples on the net, and presumably many AVR ones as well?. An LED is no use to monitor the data, use an oscilloscope. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

29th May 2008, 04:21 PM	(permalink)
nicholastyc	Hi Nigel, u r a super moderator..! thanks again. i m not using the PIC... i am using an ATSAM2195 chip from Atmel. i tried to check on the oscilloscope...the signal is very unstable from the MIDI out of the keyboard. and i found the LED test to the output, HINTON INSTRUMENTS: Professional MIDI Guide i find the signal is similar to what it was explained on the page. i will try to test it on a 6N138 opto isolator to check at the Vo . Anyone who have the experience on MIDI..please feel free to give advise. Thank you... =)

3rd June 2008, 03:40 PM	(permalink)
nicholastyc	Need some helps Hi, i need some helps..i tested on the 6N138 opto isolator, the signal seem right. after i sent the signal to the ATSAM2195 board, the output seem to be quite alots of noises. so i could not hear any sound from the speaker.. please help on me..urgent ! been working on this few days...