#include <avr/interrupt.h>
#include <util/twi.h>
#include "i2c.h"
#include "ring_buffer.h"
Defines | |
| #define | I2C_BIT_RATE_DIVIDER 0x0C |
| Set bit rate 12 = 100kbit/s (max speed setting is 10 for an 8 MHz clock). It is a divider, so the lower the number the faster the speed. | |
Functions | |
| RING_BUFFER_NEW (i2c_buffer, 128, char, i2c_write_buff, i2c_addr_buff) | |
| int | i2c_init (char addr, fun_mrecv_t master_recv, fun_srecv_t slave_recv, fun_send_t slave_send) |
| Initializes the i2c module. | |
| int | i2c_send (char dest, char *data, size_t bytes) |
| Sends a byte array over I2C as a master. | |
| int | i2c_request (char dest) |
| Send a master request to the destination. | |
| ISR (TWI_vect) | |
| Interrupt to handle I2C interrupts from the I2C hardware. | |
Copyright (c) 2007 Colony Project
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In the case where you have master sends and then a master request to the same address, you will not give up control of the line because the send and request addresses are seen as different addresses. In between it will send a restart but will not give up the line.
| ISR | ( | TWI_vect | ) |
Interrupt to handle I2C interrupts from the I2C hardware.
Uses the status codes from the I2C register to handle the events needed to advance in I2C stages. For instance, you will get a bit for receiving a start ack, then a address ack, then a data ack, etc. The events are handled in each switch case. The status codes are defined by avr-gcc in /util/twi.h but are the same codes as the Atmel documentation.
Bytes are sent by popping off the ring buffer. It also will keep track of what modes the send is in.
Errors are handled here as well.
1.5.4