kmuldrew

The arduino isn't actually necessary for this kludge; just connecting midi in line to midi out and bypassing the arduino entirely is sufficient to trigger the Roland XV2020. Maybe it just needs the midi signal to come off of a 5V rail instead of 3.3V. I wonder if someone who is more familiar with the midibox than I am can comment on the advisability of simply lifting the back of R22 from the midibox board and connecting it to 5V (maybe from J2). Would that have any adverse consequences?

Just to follow-up with this peculiar problem, I put the midi out from the midibox kb through a 6N138 optocoupler and on into an Arduino that was programmed to just forward midi bytes (the whole program is just reading a byte when it's there and then writing it back out). That output successfully triggers the Roland XV2020 to play. Not a very elegant solution, but it works. As an aside, when I first built the midi repeater, I used a 4N25 optocoupler (because it was handy and I couldn't find a 6N138 in my parts drawer). With this setup, I could not get midi into the arduino from the midibox but I could get it from a Yamaha NP31. Once I found a 6N138 and put it into the circuit, then I could receive midi signals from the midibox. Perhaps Roland did the same thing with the XV2020. Ken Muldrew.

Yes, all of the devices are sending and receiving on channel 1. Ken Muldrew.

It turns out that the midi out was working, it just won't work with the Roland XV-2020. I can use the keyboard within MIOS studio to output midi to a usb-midi cord attached to a PC, and then play that midi back to the XV-2020, but the output from the midibox just isn't recognized by the XV-2020. My Yamaha NP-31 will also recognize midi from the midibox so it must be something peculiar to the Roland synth. I wonder if anyone else has tried sending midi from a midibox to Roland gear and with what result? Ken Muldrew.

Well, this is pretty embarrassing. I switched the ends of the ribbon cable from the micromatch connectors that GEM uses to dual inline connectors (because you can buy them locally) but I didn't notice that the rows are opposite (e.g. the far left wire comes out in the front of the micromatch but in the back with the inline connectors). Somehow I also put a twist in the ribbons going from my wire-rearranging board to the DIO_MATRIX board (a momentary act of desparation, no doubt, that was quickly forgotten once data started appearing on my screen). The end result was note off commands with a reversed keyboard. Having re-done the wire-rearranging board, I now have the proper note-on messages (with correct velocity) followed by the correct note-off messages for all 88 keys. This is very exciting, so far. What I don't have yet, is communications coming out of the midi ports of the midibox-kb. The command "set kb 1 midi_ports 0x0011" is accepted but nothing comes out of midi out 1. Similarly, the command "set kb 1 midi_ports 0x0021" should put data out of midi out 2 but nothing is there. Does anyone have any ideas for this problem? Ken Muldrew.

Hi Thorsten, The 3 settings that you mentioned are set properly. When I turn off optimization I am able to get more reproducible results (hitting the same key gives the same midi code, and I can hit the same key more than once and get a midi code). Now I only get "note off" messages when the keys are released. There are no "note on" messages and nothing happens until a key is released. It looks like I have my wiring mixed up somehow. I am now getting note off a-1 (90 15 00) when I press key E-2 (but only when the key is released, nothing happens when the key is fully pressed (as an aside, isn't midi status byte "90" note on for channel 1?)). From there, descending chromatically I get the sequence leading up to E-2 when I press a-1 (i.e. pressing D#-2 gives "90 16 00", pressing D-2 gives "90 17 00", and so on until I press a-1 and get "90 34 00". I have a schematic for the keyboard and the two connectors for the left and right sides are labelled identically to those shown on the Fatar DF 88 diagram on the midibox site, so the wiring should be straightforward. I think I am going to have to trace some wires from the keys back to the DIO_MATRIX board to figure out where I have gone wrong.

I connected a Fatar TP 20/21 keyboard to my midibox kb, using the wiring diagram shown here midibox_kb_fatar_df_88_interconnections.pdf to connect the keybed to an MBHP_DIO_MATRIX board and then on to the midibox. I used the settings for a Fatar DF type with 88 keys and then started pressing some keys. Almost all of the midi messages shown in MIOS Studio are note off (with the occasional note on with velocity=127) and give the wrong note. For example, pressing C1 gives "Chn #1 note off D-2 (optimized)". Pressing C1 again does nothing, but pressing C#1 gives "Chn #1 note off C#-2 (optimized)". Then C1 can be pressed and gives the same message as before. The right side of the keyboard does not generate any messages. The most likely culprit would seem to be wiring but I can't find a problem through visual inspection. I have an analog scope and some decent meters. Can anyone suggest a good place to begin troubleshooting? Ken Muldrew.

Yes, that was it. Thank you Thorsten, all is well now. Ken Muldrew.

Thanks for the quick response Duggle. I am uploading a file called "project.hex" that comes from the "midibox_kb_v1_012" zip file. I thought that was the application, but after uploading it, I still get the "MIOS32 bootloader" message. I just tried unzipping it again and reloading the file, but with the same result. I wonder what I am doing wrong. Ken Muldrew.

I am trying to get a midibox kb board running for the first time and everything seemed to be going well until I tried typing a command to the MIOS terminal. After loading MIOS32 and then midibox_kb, in response to the Query button I get: Operating System: MIOS32 Board: MBHP_CORE_LPC17 Core Family: LPC17xx Chip ID: 0x26113f37 Serial: #C1...[lots of numbers and letters] Flash Memory Size: 524288 bytes RAM Size: 65536 bytes MIOS32 Bootloader © 2012 T. Klose If I try entering the command 'help', I get [1614116:921] help [1614116:924] [MIOS32_MIDI_SYSEX_Cmd_Debug] command handler not implemented by application I am running MIOS Studio on an older macbook pro running OS X 10.7.5. Am I missing something simple here? Thanks for any help. Ken Muldrew.