UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

SiriusHardware · 19th Nov 2017, 12:26 pm

Itam805, If I remember correctly you do a little bit with microprocessors, do you have a PicKit 2 PIC programmer by any chance?

The latest / final version (V2.61?) of the standalone PC support software for those includes a three-channel 'logic capture' tool, perfect for capturing radio-control, infra-red, serial data and in this case, MIDI data packets.

You could use that (or any other single channel logic capture tool you may have) to see if the keyboard really is sending different packets every now and again, or if it is just sending the same packet over and over again badly formed so that it is difficult for the receiver to read it consistently.

MIDI outputs are usually open-collector so you would need to connect a load (a 470R resistor, perhaps) between pins 4 and 5 on the MIDI OUT of the keyboard in order to see anything coming out.

19th Nov 2017, 12:26 pm	#9
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,586	Re: MIDI keyboard fault Itam805, If I remember correctly you do a little bit with microprocessors, do you have a PicKit 2 PIC programmer by any chance? The latest / final version (V2.61?) of the standalone PC support software for those includes a three-channel 'logic capture' tool, perfect for capturing radio-control, infra-red, serial data and in this case, MIDI data packets. You could use that (or any other single channel logic capture tool you may have) to see if the keyboard really is sending different packets every now and again, or if it is just sending the same packet over and over again badly formed so that it is difficult for the receiver to read it consistently. MIDI outputs are usually open-collector so you would need to connect a load (a 470R resistor, perhaps) between pins 4 and 5 on the MIDI OUT of the keyboard in order to see anything coming out.