raspberry pi - I2C between RPI and Arduino using Processing -

posted here code rpi master , arduino slave project. have analog sensor connected arduino , reading data processing on rpi. using processing because intend on generating graph , waveform data. code below seems work, however, slight movement of setup "disconnects" slave device because following message. "the device did not respond. check cabling , whether using correct address." have narrowed problem down , found out disconnects @ i2c.read();function. question whether there type of break function when happen processing moves on , tries again in next iteration? or if stuck in loop waiting signal slave device? have suggestions on how approach this?

processing code

import processing.io.*; i2c i2c; int val = 0; void setup() {  i2c = new i2c(i2c.list()[0]); } void draw () { if (i2c.list() != null) {  i2c.begintransmission(0x04);  i2c.write(8);  byte[] in = i2c.read(1);  int accel = in[0];  println (accel); } } 

arduino code

 #include <wire.h>  #define slave_address 0x04  int number = 5;  int state = 0;  const int zinput = a0;  int zrawmin = 493;  int zrawmax = 530;  float acceleration;  int accel;  void setup() {  analogreference(external);  pinmode(13,output);  serial.begin(9600);           // start serial output  wire.begin(slave_address);                // join i2c bus address #8  wire.onreceive(receivedata); // register event  wire.onrequest(senddata);  serial.println ("ready");  }  void loop() {  int zraw = readaxis (zinput);  acceleration = map (float(zraw), float (zrawmin), float(zrawmax), -9.81, 9.81);  accel = int(acceleration);  //delay(100);  }  void receivedata(int bytecount)   {  while (0 < wire.available())   { // loop through last  number = wire.read(); // receive byte character  //serial.print("data received");  serial.println(number);         // print character  if (number==1)  {  if (state == 0)  {  digitalwrite(13,high);  state = 1;  }  else  {  digitalwrite(13,low);  state = 0;  }  }  }  }  void senddata()  {  wire.write(accel);  }  int readaxis(int axispin)  {  long reading = 0;  int raw = analogread(axispin);  return raw;  }  

looks solution might use try/catch block courtesy of @kevin workman. works need thx.

here updated processing code.

import processing.io.*; i2c i2c; int val = 0; void setup() {  i2c = new i2c(i2c.list()[0]); } void draw () { if (i2c.list() != null) {  i2c.begintransmission(0x04);  i2c.write(8);   try  {  byte[] in = i2c.read(1);  }  catch(exception e)  {   i2c.endtransmission();  }  int accel = in[0];  println (accel); } }