RNBO and Web Serial ?
I am looking for a way to run a synthesizer on my website and connect it to an Arduino via Web Serial. I have not tried RNBO yet, but it seems perfect for the synth. Is it already straightforward to connect the Arduino to Web Serial in RNBO? Unfortunately, I have not found anything about this.
Arduino and RNBO wouldn't make a lot of sense, I've used Arduino and normal max in the past, it seems to be the best option, I would only use RNBO if I was using raspberry PI.
This is due to the fact that Raspberry can run a program by itself while arduino cannot and it's only a way to connect hardware components such as potentiometers and buttons.
I haven’t worked with the Web Serial API yet. Taking a quick look at it I’d say you would need a JavaScript program running in the client browser that connects to the Arduino serial port and uses those data to control RNBO parameters.
A RNBO patch exported for running inside the browser doesn't do any automatic hook up / magic wrt the Web Serial API. It's totally possible but you'd have to write the platform code (JS running as part of your web application) yourself in order to enable the serial data to communicate with the RNBO device.
Also note that Web Serial as of now is still an experimental technology and not supported by all browsers.
Not sure what exactly you are aiming for but if it doesn't have to run within the browser you can also use eg. the RNBO Runner export and write / run some code that handles the serial communication and translates it to OSC in order to interact with the runner. Some more info on the latter can be found here