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Connecting Two ARPs via USB to mioXL

Hi,

I've been connecting my two ARPs to my mioXL MIDI interface via USB but find that because the devices have the same device ID they sometimes switch their host ports.

Is it possible in a future firmware update to have the ability to add a unique device ID to each?

The screenshot shows what I see in the mioXL on HST7 and HST8. I know I can use MIDI DIN IN/OUT but wanted to avoid also needing to power via USB too.

Cheers

Mark

5 comments

Comments (5)

Chris Brown

Feb 03

I have dug into this topic again only to come out the other side without a solution. Ideally, the answer is to have a unique Name and Serial Number for each Midicake ARP embedded in the USB descriptor file. However, Teensy does not have a mechanism to update the USB name/serial numbers at run time (to read ARP's unique serial number). I've found a way to change the necessary values but these get overwritten when the USB logic is initialized. Creating a unique firmware build for each ARP would work but would be impossible for us to manage. Even if we installed a unique firmware during production, firmware updates would become a nightmare, with individual builds per ARP needed (on demand). I appreciate this is a really annoying issue (with several ARPs connected to my development machine I have to work around it constantly) but it is a limitation of the Teensy platform that isn't going to be resolved soon. (For anyone interested, this thread has been running since 2016) It is possible to rename devices in Windows and Mac but both will be overwritten when the device is next plugged in. Windows has the added annoyance of caching the first name and using it for all devices with the same PID. :( I will continue to search for a workaround but, for now, I don't have a better answer, I'm afraid.

submo

Feb 03

Replying to

Could you not just do an additional Firmware build that has a different Name (''MIDICAKE ARP2''), & different PID, and supply it on demand to people that have two (or maybe more) Arps?

Chris Brown

Feb 04

Replying to

Yes, I think that this is the solution. I'll be happy to do so on request. If anyone would like a second build, please ask. I'll look at putting a second build on the website too. I'll set up something in the automated build process too, because hacking the descriptor files and running manual builds is prone to error (on my part). :)

Edited

submo

Feb 02

There is a sneaky way to change the device ID (VID/PID) by editing the firmware file. I've had to do this in the past due to multiple Teensy based devices conflicting with each other as they've used the same USB VID/PID. It's easy to do, but probably not recommended as this could make bad things happen if you get it wrong. Maybe if you ask nicely enough, Chris could sort you out with an alternative firmware file that has a different device PID?

Edited

Chris Brown

Feb 02

Replying to

This is on my to do list. :) I'm looking into a solution that makes each device unique. I will report back when I get a working result.