//
// hello.ADXL343.c
//
// ADXL343 accelerometer hello-world
//    9600 baud FTDI interface
//
// Neil Gershenfeld 11/8/15
// (c) Massachusetts Institute of Technology 2015
//
// This work may be reproduced, modified, distributed,
// performed, and displayed for any purpose. Copyright is
// retained and must be preserved. The work is provided
// as is; no warranty is provided, and users accept all
// liability.
//

#include <avr/io.h>

#define output(directions,pin) (directions |= pin) // set port direction for output
#define input(directions,pin) (directions &= (~pin)) // set port direction for input
#define set(port,pin) (port |= pin) // set port pin
#define clear(port,pin) (port &= (~pin)) // clear port pin
#define pin_test(pins,pin) (pins & pin) // test for port pin
#define bit_test(byte,bit) (byte & (1 << bit)) // test for bit set
#define bit_delay_time 102 // bit delay for 9600 with overhead
#define bit_delay() _delay_us(bit_delay_time) // RS232 bit delay
#define half_bit_delay() _delay_us(bit_delay_time/2) // RS232 half bit delay

#define serial_port PORTB
#define serial_direction DDRB
#define serial_pin_out (1 << PB2)
#define light_pin (1 << PB1)

#define I2C_slave_address 0x53 // ADXL345 alt address
#define I2C_delay() _delay_us(5)
#define SCL_pin (1 << PB3)
#define SCL_pins PINB
#define SCL_port PORTB
#define SCL_direction DDRB
#define SDA_pin (1 << PB4)
#define SDA_pins PINB
#define SDA_port PORTB
#define SDA_direction DDRB

void delay(void) {
   for( volatile int i=0; i<100;++i) {
      for( volatile int j=0; j<256;++j) {
      };
   };
   return;
}

int main(void) {
   //
   // set clock divider to /1
   //
   CLKPR = (1 << CLKPCE);
   CLKPR = (0 << CLKPS3) | (0 << CLKPS2) | (0 << CLKPS1) | (0 << CLKPS0);
   //
   // initialize output pins
   //
   // set(serial_port, serial_pin_out);
   // output(serial_direction, serial_pin_out);
   //
   // main loop
   DDRB = 0xFF;
   while (1) {

      /* Define pull-ups and set outputs high */
      /* Define directions for port pins */
      PORTB = 0xFF;
      delay();
      PORTB = 0x00;
      delay();
      }
   }