So far as enclosure goes, I quite like the quality of the shapeways’ printed version of the offworld-1 case @bpcmusic designed Offworld-1: USB power utility if you are looking for some inspiration.
Wish I had a 3D printer. Maybe I can get @bpcmusic to hack something up for me in his copious free time
I’ll probably space out the teensies side to side and add a couple mounting holes in the middle of the board. Then it’d be easier to attach something laser-cut or 3D printed.
Are the optocouplers just used to keep host A and host B galvanically isolated w/ Teensys powered separately by their respective hosts? I’m wondering if this PCB would be perfect for my hypothetical Grid -> Teensy as HID keyboard -> Teletype setup.
Yes. (although I’m not sure I understand what “galvanically” means here so I googled the answer )
(Apparently theres a way to do the MIDI RX>TX TX->RX thing between the two boards without the octocouplers, but you need to flip the signal polarity or use a flux-capacitor or something - it’s just easier with the Octocouplers )
Although for your hypothetical - I believe you would need USB host on the Teensy to talk to the grid. I actually have a different bit of hardware for that scenario. If you were going to do some hacking I might be able to get you a prototype pcb for that.
This looks really interesting and like it might solve my problem of wanting to control the Gakken NSX-39 “Pocket Miku” using a small USB midi controller sans computer
So the only concern here is power. You would need to get power to the NSX-39 and the Teensy on that side of the 2host. Not sure if the 3 AAA batteries would do the trick to power the Teensy (since that’s only 4.5v max)
So… you could maybe spilt 5v power into the USB cable, or (easier) tap a couple wires into the Teensy power pins.
Current 2host software does not send Sysex, so I’d be curious to see a midi implementation chart for the NSX-39
Some info here. Charts and technical info here in Japanese. Source for some WebMIDI apps here, including the one that lets you textually program what syllables to play! Sorry that this is totally off-topic, is the time ripe for a Pocket Miku thread? I’m just thrilled (and wholly unsurprised) that other people here have one.
Hi Okyeron - I have just built my 2host and have it connected successfully to my fates build which it recognizes through the midi devices in the system settings - so far so good. When I run awake or any other script that can output a midi sequence, I see both teensyLCs light up which looks like they are communicating ok, however I am not able to see the 2host device on the other side when connecting to an Ipad. Should 2host show up as an input channel on the iPad in AUM or other synth’s midi input/out put settings?
I’ve tried to switch the input connections on both sides and get the same results. I also tried to connect to midi wrench to see if I could see it and no dice there.
Do you have any other tips in troubleshooting the connection between 2hosts and various host devices? thanks!
So with my ipad, I need to use the old camera connector kit (and a 30pin to lightning adapter) to get midi to work.
What are you using to connect 2host to the ipad? Does that same connection work for a regular midi device (like a keyboard or something)?
For other troubleshooting - try plugging the other side of 2host into your computer and see if you get midi there. That will at least confirm 2host is working as planned.
I believe the device should show up as a midi device called “twohost”
I am currently using the lightning /usb camera connection kit that is only self powered, I still need to try the cable that is has the charging connection which may work - I’ll update on that one if it changes anything and confirm on the PC side to ensure it is working as expected.
Maybe I can get 
- it’s just easier with the Octocouplers )