sending assembly code from something else than a cartdrige

Hey, does somebody know a way to send code to the snes via something else than a cartdrige ?

I'd like to interface a modern device ( ex : arduino, but it can another programmable device) with the cartdrige port and send commands directly from this device.

You'll have to build a ROMulator type device for that.

One approach is a cartridge with just a key chip and a small boot ROM that reads code from controller 2 (or from a connector on the cartridge, like the Codemasters J-Cart) and copies it to $7E2000-$7FFFFF.

Long story short: No, the SNES can only operate if given a cartridge.

Everything else is a way of using a cartridge to get the behavior you want.