RK-008 MIDI device not showing up when connected to Mac via USB

Dr. Kunz

Hi everyone,
just received my RK-008 and have a question related to USB connection to Mac: I installed the driver and was successful in testing the Settings page with Chromium (both online and offline), but no way to see the RK-008 show up as a MIDI device in the system Audio-MIDI Configuration app and Ableton. It looks like it is not connected to the Mac, but it is. Did I miss something or is it normal?
P.s: I noticed a little dim blue light in the top right corner of the panel just above the display, is it a battery charge indicator (I put a fresh BL-5C in)?

Thanks in advance
Max

albert

The RK008 doesn't act as a standard USB-MIDI device: the USB port is used as a data transport port (firmware + backup + SMF import/export).

there are 3 possibilities to connect the PC/MAC/tablet MIDI with the RK008:

use the RK008's TRS input/outputs through a MIDI interface
use bluetooth (BLE) MIDI
use 'hairless serial <-> MIDI bridge' https://projectgus.github.io/hairless-midiserial

Dr. Kunz

Thanks for the reply, unfortunately BLE isn't supported on my iMac 12,1 and Hairless midiserial crashes almost immediately when launched (MacOS 10.13.6). It looks like I should dust off my trusty Roland UA-25EX MIDI interface to connect the RK-008. Any chance to see MIDI over USB supported in the future? It would be great.

grit

There’s another post about this here:
https://bla.retrokits.com/flarum/public/d/6-how-to-use-the-rk008-with-midi-on-a-daw
And there are different flavors of hairless midi, I use it on various Mac’s and know there are some ‘hairy’ versions but I have no crashing problems with the hairless-mod-versions mentioned in that thread

Dr. Kunz

grit thanks, searching with keyword "usb" didn't get me many hits.
I tried both OldMac and MacOS versions of midiserial with mixed unsuccessful results, but slightly better respect to the one linked by @albert which didn't work at all in my system (Intel i5 AMD Radeon, macOS 10.13.6):
the frontend loads but the RK008 display goes off when I select "/dev/cu.SLAB_USBtoUART" from the Serial Port drop-down menu.
Selecting MIDI In & Out ports from the list (all IAC BUS system drivers) doesn't establish any link between the RK008 and the DAW (Ableton).
If I deselect the Serial Port from the list the RK008 display lights up. I tried various serial port settings but not any single possible combination, as a starter what is the correct bitrate/data bit/parity/stop bit combination for the RK008?
Really not a vital issue here, but it got my attention and I would love to see it working.

grit

the RK008 resets when it makes a connection (which is kind of normal) but does not boot up again? Not sure why that would happen, maybe because the input and output port linked to the serial port are flooding the RK008 in loopback? I make two virtual ports and send midi-out to one port and midi-in to another. The serial parameters are:

baud: 38400
databits: 8
parity: none
stop bits:1
flow control: hardware

Dr. Kunz

Getting there.
With both Hairless v0.4 mod 8 versions, the port settings above the RK008 keeps shutting down when the "serial port bridge" checkbox is flagged and the midiserial driver is selcted from the list. Different IAC bus ports are selected for input and output.
Then I decided to test again the version 0.4 for macOSX and this time it didn't crash; it inherited the settings from the other builds I tested, the data monitor wasn't running like a mad with error messages anymore, and a single sysex message appeared for the first time. From there I managed to sync Ableton to the RK008 and RK008 to Ableton (CLCKSRC = RK006). So far, so good. Thanks for the support!

albert

the RK008 resets, because one of the handshake lines of the USB port is connected to the reset pin of RK008's CPU