programming the Chameleon help me on the way

[arpeggio]

Hello everybody Chameleon fans, i am trying to program the Chameleon,
Basic works good' sending to Chameleon.
Modifying the Levelmeter program to send also send a midi CC message
So i can control a midi synth with the Level of the guitar,
Can someone help me how to combine a midi message out with the Level meter program,
Thanks in advence, Dian from the Netherlands

[DrJustice]

It's many years since I last programmed for the Chameleon, but after a quick dive into some old sources and little editing, the following (untested!) two functions might be useful.

The first one, initialize_midi(), must be called once when you initialize your soundskin. The second is a general function for sending MIDI CC messages.

E.g. to control the volume of the synth, setting the sound on channel 1 to half volume, you'd use MIDI control change 7 (Channel volume), like this:

[arpeggio]

Wow man this is a lot more complicated than Arduino and a little Cplus,
This is as much i already kwow from my reading, and digging in the Chameleon knoledge base, trying the understand the way i, one has to write program pices, and combine everything together in a program as a hole.
But the way of understanding is the same, know what you want and get the right ingredients and put them in the precice order.
I try it in a few days and let you know, have to find a place to put the void that sends the midi message, find the value from the dsp level to use and indeed i can find a way to scale the values to eachother.
Thanks, Dian

[DrJustice]

It's not as complicated as one might first think

Once you have those two functions included in your program, you can "forget about them", and just use a single statement:

[arpeggio]

Hello, the code DrJustice suggested builds well but does not work jet,
This is how i build it up together,
Thanks for your interest and concurn, i apriciate that a lot.
Dian

[blue hell]

initialize_midi only returns a value (-1) when:

(! midi_ref) is true .. so when midi_ref == false, and so the function result is s undefined then ... should prolly add something like

return 0;

just before the last }

that would make the compiler happy, not sure if it would be enough to make you happy ...

[DrJustice]

Yes, Jan is right! Just add a "return 0;" at the end of the "initialize_midi()" function.

As mentioned, that function also needs to be called once when you initialize things. I suggest adding it after "start_dsp();" in the "rtems_main()" function.

However, and more importantly, the source you posted is not the one I was thinking of, or more precisely, it is incomplete/modified/garbled (there are e.g. missing variables and erroneous constructs - it will not compile without many errors).

The original level meter I was thinking about can be found here.

If you use that, then we have a common reference, and the example in my 2nd posting is applicable. Since it only took a couple of minutes to do, I have attached "main.c", modified as discussed in the previous postings. It's still untested, so no guarantees, but that's the principle.

On line 65 and 78, the "initialize_midi()" and "transmit_control_change()" functions have been inserted. I put the "midi_ref" variable on line 40, together with the other global variables.

On line 325 you will see the call that transmits the control changes:

[blue hell]

[DrJustice]

You're right again, Jan!

One would have thought that the code tags took care of things, but they don't... I tried a few edit/preview cycles with the source in and out of code tags, and only the "Disable HTML in this post" avoided mangling the source.

[arpeggio]

Hello again, still trying the put things together, this is the best way the learn for me, try and make things work, thinkening, thanks for the tips and tricks,
and the help, i could not do without it in this languese, it's alot the take care about, but when you get the way off doing things, i will like that,
Anyway, the code builds without errors and no warnings, i had the first put midishare.h in the beginning, but it sends no midi CC messages out, still not.
Does one have to define a MIDIPHYS_IO 0 kind of thing, i read in the midishar docs, or open up something for midi to work,
And i build the levelmeter ELF file in another folder where the levelmeter zip extraction went, so maybe i mangled thing up a bit,
Indeed i used a wrong levelmeter code, the one in debug, and i had to use the one in the src map, so i put it there your main.c file, drJustice, but the Elf file came in debug,
Question: is puting the right adres in the make file a good way to handle this, what. will be a good way the know you put the right thing together,
Or do i make it to complicated for myself, just follow the steps and it will be okay, and the levelmeterMIDI code not working thing lies in another issue,
So thanks again for the help, and i will make a nice code, audio level to midi CC and i can control the volume, or filter intencity level with my guitar playing level, looks very nice
Dian

[arpeggio]

What i meant by the midi thing was midiconnect, and make a define for PHYSMIDI_IO 0, that was what i read in the midishare docs,
Maybe this is needed to,
Dian

[arpeggio]

Hello again, got it working, made a new Elf-file, called it levelmeter1, 2, etc.
This for knowing whats new and finding back things.
Included MidiShare.h, did the PHYSMIDI_IO 0 thing, and ofcource used the good begin code with drJustice thing in it, see above.
Then it sended midi CC 7 to channel 2, midi channels go from 0 to15, changed channel to 0, is 1 for real.
And then the values akt strange, so i changed the >> 5 to >>4, and it got
better but still akting strange, so i put transmit_control_change...etc
after Level_L=log10......etc and use just level_l for value, and it was beter,
And then level_l * 3 for value and that was good, the CC value on the screen in PD moved in the same way the bargraph meter on the Chameleon was moving.
Thanks for all the help and advice, and i will post a midi-file soon for the people who wants to try it out, and play with audio control to midi.
Dian

[DrJustice]

Nice, Dian

You're abolutely right, there should be a

[arpeggio]

Debugging with values for midi CC messages on the screen,
Goes very fast, how can i get the autoscroll to stop and view the values
i will scroll to,
Dian

[DrJustice]

You can change the update rate in this line:

[arpeggio]

Joepie, thats dutch for and nice.
Works great,
Still i get the best results using the CC_value after Level_L=log10,
then the values produced look the same as the values on the Chameleon bargraph.
And a little question for further programming with Midi in and Midi out,
Midi out i can do now, but Midi in
what will be a a general function for recieving MIDI CC messages and Midi-Notes
Thanks people, you have helped me a lot, and this would keep the coding and DIY stuff alive, Dian

[DrJustice]

Glad to hear that you get things working!

I'd still be looking a bit at the values you're getting, that log value isn't really what should be used in normal circumstances. I might look at both values in the TRACE statement to figure out what's going on. As mentioned you should normally be using a value between 0 and 127 when dealing with MIDI:

[arpeggio]

Hello, i got midi in working, but as suggested, the multithreading thing, the
level meter task stops when i put in a few midi-message together, when it is not a lot together' then it works fine, so the Midi-in code is good, by the way, had to remove a few, 3, ")" at the end of the midigetfield sentence, i kind of get used to the coding and finding a way to build things, a little, but the beginning is there and it's fun for me and it payes of a great deal, for me and for the
diy community. And you spoke about midi-callback, i know that from the arduino midi-library, can you tell me how that works, so how the code basics looks like. So i can try to find a way to handle the midi-in thing, maybe put the midi_poll thing in the main loop, or at the end of the whil()loop, or some other place, or do you think i have to get another approce for handling this multithreading thing,
By the way, left out the PHYSMIDI_IO 0 thing and that builded fine too, so you had it right that it was not needed.
And later on i will drop some test results for the level_L value, that keeps puzzling me, a 12 digit is 4095 max, so it should work the way you suggested, but it does not, i will let you know.
Thanks again, Dian

[DrJustice]

I'm not sure what you mean by "level meter task stops when i put in a few midi-message together, when it is not a lot together' then it works fine...". Normally there's no problem sending and receiving any number of MIDI messages - could it be an error elsewhere (not caused by MidiShare as such)?

The callback method is implemented by calling the MidiShare function MidiSetRcvAlarm() with the midi_ref and a pointer to a function that you define. Your function will then be called when there's incoming MIDI data in the receive buffer, and the you can read the MIDI event in basically the same way as the midi_poll() example.

Regarding the multithreading, it's not 'dangerous' unless two threads try to modify the same data; then the dilemma is which change should be the latest valid one... If that's not resolved, the program may become 'confused', and at worst crash (depending on what the program, does with the data that is shared between threads). If two threads want to change the same data, you must use thread synchronization mechanisms such as a 'mutex' (mutual exclusion). Don't worry about that before you have that need.

As for the 0-127 range problem, I can't see any obvious explanations - at this point you're in a better position that me to find out since you run and debug the code

[arpeggio]

The while loop where the level_meter_task runs has this message at the end, look at the source code, after the 'should never be here' sentence, and this happens when i put in a lot of midi data,
And when i put in a few data, then the code runs fine and the meter moves
good and the incoming midi-data is monitored in the debug-window,
so i will get experinenting with this in a while, let you know.

Thanks for the callback midi info, will try this in a while, let you know.
Thanks again, happy coding, Dian

[DrJustice]

Ending up at "Should never be here" most likely happens because the Chameleon gets so busy processing incoming MIDI for a moment, that it misses a timer period - this happens either internally in MidiShare or in poll_midi() (I suspect the latter is most plausible, with the TRACE statements possibly taking a bit of time). See the snippet from level_meter_task() below:

[arpeggio]

Hello, try to install a reveive alarm for midi in the levelmeter example
But get errors,
in Function OneSecDelay
Parse error before character 0321
Parse error before }
and Types defaults to int in function ......
Conflicting types in function.....

The piece of code is this I put it near Midi functions

[blue hell]

[arpeggio]

Hello, i got this from the MIDIshare site, in the example they gave for the
MidiSetRecAlarm, looks strange though.
Looking further, Dian

[DrJustice]

I agree with Jan on using n--, as in: