Communication over USB to firmata

[puttley]

Hello,

I have used Ardublockly successfully and am familiar with how to create custom blocks for generating Arduino code. I'd like to know how if it may be possible to modifly Ardublockly so that a custom block can communicate over serial USB to Arduino without uploading code to the target. I'd like to have custom firmata running on the Arduino target, then write/read bytes to it without actually compiling and uploading code - similar to how Scratch works. Thank you for the tips and help.