Keyboard is recognised but doesn't work

[merlyn]

In the original post the OP wrote:

I contacted Dexibell manufacturer and they said driver is not required.

I took this to mean the device is class compliant. I had a look on the Dexibell site and there is no driver to download for any OS.

It does raise the question of what exactly "class compliant" means. Having thought class compliant = Linux compatible I am now not so sure. A device that appears to be class compliant i.e. is plug and play on Linux may have a quirk in quirks-table.h, so it's not truly class compliant. New hardware, such as the Dexibell in question, may not have a quirk yet and so doesn't work on Linux.

I would now think the best way to determine if a device is Linux compatible is to plug it in and see. And when researching new hardware the best indicator of Linux compatibility would be to find someone online who has tried it.

[davis]

In the original post the OP wrote:

I contacted Dexibell manufacturer and they said driver is not required.

I took this to mean the device is class compliant. I had a look on the Dexibell site and there is no driver to download for any OS.

It does raise the question of what exactly "class compliant" means. Having thought class compliant = Linux compatible I am now not so sure. A device that appears to be class compliant i.e. is plug and play on Linux may have a quirk in quirks-table.h, so it's not truly class compliant. New hardware, such as the Dexibell in question, may not have a quirk yet and so doesn't work on Linux.

I would now think the best way to determine if a device is Linux compatible is to plug it in and see. And when researching new hardware the best indicator of Linux compatibility would be to find someone online who has tried it.

I've been contacting with Dexibell support (which is very welcoming and friendly) for a few days now. Dexibell instruments are supposed to work on Win OS, macOS AND Linux with no problems. At this point all I've left is trying connect Dexibell on different OS and maybe also different cable (although I doubt cable is a real problem).

[merlyn]

Have you tried the CP-33 with this exact setup? If that works then the USB cable and OS are good and the problem is with the Dexibell.

Drivers on Linux are kernel modules -- it's a very different setup from Windows. You can see what kernel modules are loaded with lsmod. This produces a long list so to find what you're looking for use grep. I've booted my system with my USB keyboard turned off. I get this from lsmod :

Code: Select all

$ lsmod|grep midi
snd_seq_midi           20480  0
snd_virmidi            16384  0
snd_seq_virmidi        16384  1 snd_virmidi
snd_seq_midi_event     16384  2 snd_seq_midi,snd_seq_virmidi
snd_seq                90112  3 snd_seq_midi,snd_seq_midi_event,snd_seq_virmidi
snd_rawmidi            45056  3 snd_seq_midi,snd_seq_virmidi,snd_mpu401_uart
snd_seq_device         16384  3 snd_seq,snd_seq_midi,snd_rawmidi
snd                   114688  19 snd_hda_codec_generic,snd_seq,snd_ak4xxx_adda,snd_cs8427,snd_seq_device,snd_hda_codec_hdmi,snd_hwdep,snd_hda_intel,snd_hda_codec,snd_hda_codec_realtek,snd_timer,snd_virmidi,snd_ice1712,snd_ac97_codec,snd_seq_virmidi,snd_i2c,snd_mpu401_uart,snd_pcm,snd_rawmidi

The USB MIDI module/driver is not loaded. Now if I turn my MIDI keyboard on I get this :

Code: Select all

$ lsmod|grep midi
snd_usbmidi_lib        40960  1 snd_usb_audio
snd_seq_midi           20480  0
snd_virmidi            16384  0
snd_seq_virmidi        16384  1 snd_virmidi
snd_seq_midi_event     16384  2 snd_seq_midi,snd_seq_virmidi
snd_seq                90112  3 snd_seq_midi,snd_seq_midi_event,snd_seq_virmidi
snd_rawmidi            45056  4 snd_seq_midi,snd_usbmidi_lib,snd_seq_virmidi,snd_mpu401_uart
snd_seq_device         16384  3 snd_seq,snd_seq_midi,snd_rawmidi
snd                   114688  22 snd_hda_codec_generic,snd_seq,snd_ak4xxx_adda,snd_cs8427,snd_seq_device,snd_hda_codec_hdmi,snd_hwdep,snd_hda_intel,snd_usb_audio,snd_usbmidi_lib,snd_hda_codec,snd_hda_codec_realtek,snd_timer,snd_virmidi,snd_ice1712,snd_ac97_codec,snd_seq_virmidi,snd_i2c,snd_mpu401_uart,snd_pcm,snd_ra midi

The relevant module is snd_usbmidi_lib.

[davis]

Have you tried the CP-33 with this exact setup? If that works then the USB cable and OS are good and the problem is with the Dexibell.

Drivers on Linux are kernel modules -- it's a very different setup from Windows. You can see what kernel modules are loaded with lsmod. This produces a long list so to find what you're looking for use grep. I've booted my system with my USB keyboard turned off. I get this from lsmod :

Code: Select all

$ lsmod|grep midi
snd_seq_midi           20480  0
snd_virmidi            16384  0
snd_seq_virmidi        16384  1 snd_virmidi
snd_seq_midi_event     16384  2 snd_seq_midi,snd_seq_virmidi
snd_seq                90112  3 snd_seq_midi,snd_seq_midi_event,snd_seq_virmidi
snd_rawmidi            45056  3 snd_seq_midi,snd_seq_virmidi,snd_mpu401_uart
snd_seq_device         16384  3 snd_seq,snd_seq_midi,snd_rawmidi
snd                   114688  19 snd_hda_codec_generic,snd_seq,snd_ak4xxx_adda,snd_cs8427,snd_seq_device,snd_hda_codec_hdmi,snd_hwdep,snd_hda_intel,snd_hda_codec,snd_hda_codec_realtek,snd_timer,snd_virmidi,snd_ice1712,snd_ac97_codec,snd_seq_virmidi,snd_i2c,snd_mpu401_uart,snd_pcm,snd_rawmidi

The USB MIDI module/driver is not loaded. Now if I turn my MIDI keyboard on I get this :

Code: Select all

$ lsmod|grep midi
snd_usbmidi_lib        40960  1 snd_usb_audio
snd_seq_midi           20480  0
snd_virmidi            16384  0
snd_seq_virmidi        16384  1 snd_virmidi
snd_seq_midi_event     16384  2 snd_seq_midi,snd_seq_virmidi
snd_seq                90112  3 snd_seq_midi,snd_seq_midi_event,snd_seq_virmidi
snd_rawmidi            45056  4 snd_seq_midi,snd_usbmidi_lib,snd_seq_virmidi,snd_mpu401_uart
snd_seq_device         16384  3 snd_seq,snd_seq_midi,snd_rawmidi
snd                   114688  22 snd_hda_codec_generic,snd_seq,snd_ak4xxx_adda,snd_cs8427,snd_seq_device,snd_hda_codec_hdmi,snd_hwdep,snd_hda_intel,snd_usb_audio,snd_usbmidi_lib,snd_hda_codec,snd_hda_codec_realtek,snd_timer,snd_virmidi,snd_ice1712,snd_ac97_codec,snd_seq_virmidi,snd_i2c,snd_mpu401_uart,snd_pcm,snd_ra midi

The relevant module is snd_usbmidi_lib.

Thanks for your detailed reply! I'm not that naive (read dumb). I have sold Yamaha cp-33 about 1 year ago.. So my last option is to test it on different computer with Windows/Mac.

[Baggypants]

Well that’s a little annoying, I assumed when you said it worked with the cp-33 it was working now, it working a year ago is pretty meaningless, any number of things could have changed or broken in that time. What I would do is download a Linux image and boot from usb to check your Linux isn’t somehow broke.

[davis]

Well that’s a little annoying, I assumed when you said it worked with the cp-33 it was working now, it working a year ago is pretty meaningless, any number of things could have changed or broken in that time. What I would do is download a Linux image and boot from usb to check your Linux isn’t somehow broke.

Linux isn't somehow broke.. what do you even mean?