Cheap RF transmitter/receiver for clock sharing

#1

Hi!

I am thinkering about starting a "marching band" of Axo based synths.
Having cables between the independent cores is a bit of a hassle when walking the streets and limits freedom of movement a bit too much. So I was exploring the idea of using RF RX/TX modules to send a clock signal from one core to the others.

Browsing the net I stumbled upon these cheap boards:

Anybody any experience/thoughts/suggestions whether this path would be worth investigating? Or are there immediate showstoppers?
I can imagine especially lag and maximum clock frequency could be a stopper.
With my limited knowledge on the subject it seems that the board only need a high and low digital signal (from the axo).
(EDIT: checking again, that is what I would want them to do...not sure whether it works like that, should dig in deeper..)

Any thoughts/suggestions warmly appreciated!
enjoy!

#2

more details of a possible route:

#3

Not sure about latency and lag. These devices are usually used for remotely turing on and off lamps and other household devices. They do have a simple encryption pattern for authentication so that the neighbour can not interfere with your devices.

Not sure whether it would be suitable for syncing music.
Did you look into wireless Midi?
DIY wireless Midi might be possible with a teensy:
https://forum.pjrc.com/threads/30867-Wireless-MIDI-controller-Aid

Would leave the door open for integrating other wireless Midi stuff later.

#4

hi jsilence,

Thanks for pointing out wireless midi, but I skipped that path, first because I am looking for a simple solution with just a clock signal (metronome style). And second because it would become a little bit to costly... On the other hand that path would allow for other non-axo synths to joint the walking party :wink:

I guess I'll just give it a try, these modules come very cheap...

#5

I'm vaguely interested in wireless Midi and in the Teensy microverse. The Teensy seems to be well suited for audio applications and I am working (very slowly) on designing a small 4 channel stero mixer with it. Would like this device to also act as a Midi hub.
Adding wireless Midi would be a plus, I guess.

#6

I found a screenshot on my desktop of a short experiment I did with these modules a while back.
It was a quick and dirty test, but I thought I'd share it here...

I simply connected sender and receiver module to 2 gpio's (one for sending, one for receiving the signal) on the same axoloti. The sender and receiver were approximately 1m apart.

The maximum send rate (at which all signals seemed to arrive) appeared to be 2.29Hz.
The latency that I measured was 64.79ms.

So: for clock signals this path is clearly not usable (as probably most of you might have guessed;-). But it could be an interesting technique for art installations etc where latency of around 65ms is acceptable and you need to remotely control lamps, motors etc...

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have fun!

#7

It could be seens as just a sync signal that would be sent every minute or so, in this case the axoloti's would resync every minute which might be more than enough. In professional film equipment audio video sync is sometimes done that way, with devices drifting appart from others slowly enough to make it a workable solution.