#include <Wire.h>
          void setup() {
            Serial.begin(9600);
            Wire.begin(); // join i2c bus (address optional for master)
            pinMode(0, OUTPUT);
          }
          void loop() {
            while (Serial.available()) {
              char c = Serial.read();
              if (c == 'H') {
                Wire.beginTransmission(9);
                Wire.write('H');
                Wire.endTransmission();
                Serial.println("writing to address 9!");
              }
              else if (c == 'L') {
                Wire.beginTransmission(9);
                Wire.write('L');
                Wire.endTransmission();
                Serial.println("writing to address 9!");
              }
              else if (c == 'G') {
                Wire.beginTransmission(8);
                Wire.write('G');
                Wire.endTransmission();
                Serial.println("writing to address 8!");
              }
              else if (c == 'K') {
                Wire.beginTransmission(8);
                Wire.write('K');
                Wire.endTransmission();
                Serial.println("writing to address 8!");
              }
            }

          }