// need 0.1uf cap between vcc and ground for proper operation
// need 10k pull up resistor on scl and sda for i2c to work correctly

// Pin Mappings (Per TinyCore)
// ATTiny Pin  -- Arduino Pin
//    01           RESET
//    02           ADC3/PB3
//    03           ADC2/PB4
//    04           GND
//    05           PB0/AIN0/SDA
//    06           PB1/AIN1
//    07           PB2/ADC1/SCL
//    08           VCC

// i2c ATTiny Pins
// sda: 5
// scl: 7

#define I2C_ADDRESS 0x5F

#include <Wire.h>

void setup() {
  pinMode(6, INPUT);
  
  Wire.begin(I2C_ADDRESS);
  Wire.onRequest(requestEvent);
}

void loop() {
  delay(100);
}

// function that executes whenever data is requested by master
// this function is registered as an event, see setup()
void requestEvent() {
  Wire.write((uint8_t) analogRead(6)); // Only get 0 - 1023 back so move this into a 1 byte int
}