Firmata and Max/MSP - help please

I would like to use Firmata for communication between the Arduino and Max, but I am having a hard time finding resources to help me figure out how I need to implement Firmata.

I would like to: 1. send analog values (from a MPC23008 Analog Mux) to Max 2. have a scaling function in Max (to scale the values from1-100 or 0-127) 3. send this scaling factor (or the A/D values) back to the Arduino, as well as other strings to be sent over i2c to an LCD.

Getting values to Max and scaling is no problem. I am mostly confused about sending ints and strings back to the Arduino from Max through Firmata. I am also unclear about how the callbacks work/what function they play, and how to send several values, keeping them organized, from Max to the Arduino.

Any help or suggested readings would be great! I'm sure I'm not the first n00b to need help with the Firmata library!

Why Firmata? You can use also SimpleMessageSystem. Its basicly built to read/write analog or digital pins, but you can customize it and send int. With string I am not sure. I use it for sending values from MAX and that values is set to specified varibales in Arduino. Works good - but one problem I have - when sending any data the connected led to arduino stops shining for very short moment.