Arc2 and 128 Connectivity Issues on Windows

I took a video of Max and returns, maybe will help showing the problem. In Max it takes a little bit longer to drop, I suspect because there is less light action when just turning knobs. Link: (Google is still processing the file, so might be low res, but can be downloaded high res)

@Markus, just to make sure - are you running the 1.4.1b serialosc binary?

@artfwo Yes," a" didn’t even work with one grid, similar symptoms at that time

1 Like

Cool, I’m gonna have a look at the problem this week.

1 Like

Ok, let me know if there’s anything I can do to help

To anyone having issues with arc on Windows 10, please use the following serialosc binary as temporary solution (64-bit systems only):

Uninstall any previous versions of serialosc, before installing the above binary.

Please do not use this binary if you don’t experience any issues, as it is a preliminary fix, a proper release will follow. Thanks to @Markus for the help with testing the fix!


Thank you @artfwo! This version of serialosc seems to fix the problems I was having with my Grid 128 on Windows 10. I just ran Polygome in Max4Live with 1.4.2-pre for over an hour with the grid remaining responsive and lights working. With the previous versions (1.4.1a and b), the grid lights would always freeze after 5 to 15 minutes, requiring a power cycle to work again. Hope everyone else with issues finds this and tries it.

1 Like

Hi @artfwo - I’ve recently acquired a 2018 arc4 and am experiencing the same problem. By connecting to serial osc from TouchDesigner, I can confirm that this appears to be an issue with serialosc itself. Installing serialosc-1.4.2-pre (subjectively) seemed to improve the situation, but definitely didn’t completely solve the issue. There are still dropouts where the serialosc appears to drop communication bidirectionally.

Is serial-osc open sourced? I’d be happy to help bug hunt if so - I want to use arc as the primary interface of a new creative application I am developing (I haven’t found a more precise commercially available controller!), but am being limited by these frequent disconnects. Is there an open source implementation of a raw serial connection? That might end up being better for my needs anyways.

serialosc is free software, see

the problem with windows 10 happens because the ftdi driver buffers the output from device differently and serialosc gets less data from the port than it expects.

with the 1.4.2-pre fix above this particular problem shouldn’t happen, because serialosc loops until the input buffer is complete. are you sure you have uninstalled the previous version?

Hi @artfwo, thanks for the quick response.

I’m pretty sure I reinstalled it correctly, I can try a uninstall/reboot/reinstall/reboot cycle just to make sure the windows services are cleared out.

Good news though - I’m connecting directly to the arc via serial in TouchDesigner, and have already converted all the relevant api calls. The latency is incredibly low (especially using a 120fps patch) and the sensitivity is absolutely out of this world! Haven’t had any drops (other than crashes of connection when sending invalid commands accidentally during testing, a quick unplug and reconnect resets everything just fine). I’ll probably stick to serial for my custom applications, though I’m hoping the win10 issues for serialosc get solved for using other people’s Max patches like Capstarc. Thanks for looking into this!

  • Jonathan

Yes, restarting the system might be necessary.

It works! My Arc is working smoothly with all M4L devices now!

It is much more stable, but if I close down an Ableton project, and open another one, it is suddenly not recognized, and the only fix I have found is to restart the computer

is the arc also not recognized from other clients, i.e. the monome package for max?

FYI on my new laptop, plugging in my grid 256 VB and arc4 did not trigger an automatic install of the ftdi driver (iirc it did in the past on another system).
Q: which driver is suggested?
I suggest to link to the ftdi driver package again in monome docs

It might have been installed in the background or you had it already.

The driver provided by Windows works very well (it’s actually provided by FTDI via Windows Update), there is no need to install any other drivers.

Actually it didn’t (for some reason) that’s why I am writing here :slight_smile: .
I had to install twice manually. Before that, device manager said that there weren’t any drivers installed for the devices and a search thru windows update didn’t yield any results.
After the first installation device manager showed two usb devices, but still unknowns as well. A second install directing search to the downloaded ftdi drivers succeeded and it now works fine.

Well, that’s weird. What’s you version of Windows? Do you have Windows Update disabled perhaps?

Indeed, still on 20H2, windows update is enabled.
New Lenovo x1 yoga gen 6

@tehn, I recall you had to reinstall the driver twice on a yoga laptop too?