[PD] chronometer + metronome that syncs multiple Android/iOS devices over network?

Chris McCormick chris at mccormick.cx
Wed Mar 6 04:13:59 CET 2019

Hello Enrike,

On 6/3/19 12:18 am, enrike wrote:
> We need a chronometer that runs in sync in multiple devices at the same 
> time.

SyncJams might work for you:


The algorithm it uses is tolerant of adverse network conditions. All 
devices run their own internal clock and the clocks converge on a 
consensus "current tick".

The algorithm is very simple: every device broadcasts its current tick 
over the network. If a device receives a tick which is higher & earlier 
than it expected it immediately resets its own clock to that new timing.

What this means in practice is the smallest (i.e. best) point-to-point 
ping time between any two participating patches is the closest that the 
clocks will get in sync. On a WiFi LAN this is generally on the order of 
1 to 3 milliseconds which is close enough for most musical applications. 
In my experience devices converge on that value quite quickly after 
joining the network.

Here's a video of Chris Rice aggressively changing the BPM from which 
the devices manage to recover after a second or two:


Here are two Android devices syncing:


I've been planning to revisit the project to simplify it and port to 
Supercollider etc. for some time but who knows if I'll ever get around 
to that.




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