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i2c.c
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i2c.c
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/***********************************************************
* File: i2c.c
* Created on: Nov 19, 2017
* Author: Rod Naugler - B00064907
* Dalhousie University
* Description: As part of ECED4901 - Senior Design Project
* For Omnitech Electronics.
* This file contains all of the generic i2c code.
* Individual chip code moved to separate files
***********************************************************/
#include <stdio.h>
#include <avr/io.h>
#include <avr/pgmspace.h>
/*************************
* Generic I2C Routines *
*************************/
void TWI_Start(void) { //TWI - Two Wire Interface
TWCR = (1<<TWINT)|(1<<TWSTA)|(1<<TWEN); //TWCR - TWI Control Register
//TWINT - TWI Interrupt Flag - Reset
//TWSTA - TWI Start Condition - Assert
//TWEN - TWI Enable - Assert
loop_until_bit_is_set(TWCR, TWINT); //Wait until the TWINT flag is set, which
//means that the start condition was successful
}
void TWI_Stop(void) {
TWCR = (1<<TWINT)|(1<<TWSTO)|(1<<TWEN); //TWINT - TWI Interrupt Flag - Reset
//TWSTO - TWI Stop Condition - Assert
//TWEN - TWI Enable - Assert
loop_until_bit_is_clear(TWCR, TWSTO); //Wait until the TWINT flag is set, which
//means that the stop condition was completed
}
void TWI_sendByte(uint8_t cx) {
TWDR = cx; //TWDR - TWI Data Register - load the byte
TWCR = (1<<TWINT)|(1<<TWEN); //TWINT - TWI Interrupt Flag - Reset
//TWEN - TWI Enable - Assert
loop_until_bit_is_set(TWCR, TWINT); //Wait until the TWINT flag is set, which
//means that the data register is now empty
}
uint8_t TWI_readByte(char sendAck) { //Returns a byte. sendAck = 1 = TRUE
if(sendAck){ //If we want to send the acknowledge after reception
TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWEA); //TWINT - TWI Interrupt Flag - Reset
//TWEN - TWI Enable - Assert
//TWEA - TWI Enable Acknowledge - Assert
} else {
TWCR = (1<<TWINT)|(1<<TWEN); //TWINT - TWI Interrupt Flag - Reset
//TWEN - TWI Enable - Assert
}
loop_until_bit_is_set(TWCR, TWINT); //Wait until the TWINT flag is set, which
//means that the data register is now full of data
return TWDR; //Return the data byte
}
uint8_t TWI_status(void) { //TWSR - TWI Status Register - Only 5 MSB are status
return TWSR & 0xF8; //Mask off 3LSB and return the Status Register
}
uint8_t checkDevice(uint8_t SLA){ //Check to see if there is a device at
//the supplied address or not
uint8_t tmp; //A temp variable for the status
TWI_Start(); //Send the TWI Start
TWI_sendByte(SLA); //Send the slave address (write address)
tmp = TWI_status(); //Get the TWI status byte
TWI_Stop(); //Send the TWI Stop to release the bus
if (tmp == 0x18){ //If the status is 0x18, the ACK was rxd
return 1; //So return a TRUE (present) message
} else { //Otherwise,
return 0; //Return a FALSE (absent) message
}
}
/******************************
* EEPROM Specific Routines *
* - NO error handling done! *
******************************/
void writePoll(uint8_t SLA) { //SLA - Slave Address
char busy = 1; //Status bit
while(busy){ //Run this loop until we get a response
TWI_Start(); //Start the TWI
TWI_sendByte(SLA); //Send a byte on the TWI that is the Slave Address
//
if(TWI_status() == 0x18){ //0x18 - SLA+W has been transmitted; ACK has been received
//0x20 - SLA+W has been transmitted; NOT ACK has been received
//OK
busy = 0; // If we recieved an ACK to the address, the device is ready
}
}
}
void writeByteEE(uint8_t SLA, uint8_t addr, uint8_t data) {
TWI_Start();
TWI_sendByte(SLA);
TWI_sendByte(addr);
TWI_sendByte(data);
TWI_Stop();
writePoll(SLA);
}
uint8_t readByteEE(uint8_t SLA, uint8_t addr) {
uint8_t tmp;
TWI_Start();
TWI_sendByte(SLA);
TWI_sendByte(addr);
TWI_Start();
TWI_sendByte(SLA | 0x01);
tmp = TWI_readByte(0);
TWI_Stop();
return tmp;
}
//You can extend these to have error handling - see http://www.embedds.com/programming-avr-i2c-interface/
//for example
/************************
* MAX5217 DAC Routines *
************************/
void setDACoutput(uint8_t SLA, uint16_t value) {
TWI_Start(); //Send the TWI Start
TWI_sendByte(SLA); //Send the slave address
TWI_sendByte(0x01); //Send the CODE_LOAD command - immediately
//set the following 16 bit value on the DAC output
TWI_sendByte(value>>8); //Send the high-byte
TWI_sendByte(value&0xff); //Send the low-byte
TWI_Stop(); //Send the TWI Stop
}
uint16_t readDAC(uint8_t SLA, uint8_t reg){
uint16_t tmp; //The 16-bit value to return
uint8_t tmph; //High byte
uint8_t tmpl; //Low byte
TWI_Start(); //Send the TWI Start
TWI_sendByte(SLA); //Send the slave address (write address)
TWI_sendByte(reg); //Send the address to read from
TWI_Start(); //Send a repeated start
TWI_sendByte(SLA+1); //Send the slave address+1 (read address)
tmph = TWI_readByte(1); //Read data from TWI (high byte) ACK
tmpl = TWI_readByte(1); //Read data from TWI (low byte) ACK
TWI_Stop(); //Send the TWI Stop
tmp=tmph << 8; //Move the high byte into the high byte position
tmp=tmp+tmpl; //Add the low byte
return tmp; //Return the 16-bit value
}
void resetDAC(uint8_t SLA) {
TWI_Start(); //Send the TWI Start
TWI_sendByte(SLA); //Send the slave address (write address)
TWI_sendByte(0x08); //Send the User Config Command
TWI_sendByte(0x00); //Send the 'Don't Care' byte
TWI_sendByte(0x00); //Send the config byte
//xxCCAAPP CC - Clear Value Mode, AA - AUX mode, PP - Powerdown Mode
//cc - Default, cC - Zero, Cc - Mid, CC - Full
//aa - Disable, aA - LDAC, Aa - Clear, AA - Disable
//pp - DAC, pP - High Z , Pp - 100k, PP - 1k
TWI_Stop(); //Send the TWI Stop
}
/***********************************
* LTC2946 Energy Monitor Routines *
***********************************/
/*void setDACoutput(uint8_t SLA, uint16_t value) {
TWI_Start(); //Send the TWI Start
TWI_sendByte(SLA); //Send the slave address
TWI_sendByte(0x01); //Send the CODE_LOAD command - immediately
//set the following 16 bit value on the DAC output
TWI_sendByte(value>>8); //Send the high-byte
TWI_sendByte(value&0xff); //Send the low-byte
TWI_Stop(); //Send the TWI Stop
}
uint16_t readDAC(uint8_t SLA, uint8_t reg){
uint16_t tmp; //The 16-bit value to return
uint8_t tmph; //High byte
uint8_t tmpl; //Low byte
TWI_Start(); //Send the TWI Start
TWI_sendByte(SLA); //Send the slave address (write address)
TWI_sendByte(reg); //Send the address to read from
TWI_Start(); //Send a repeated start
TWI_sendByte(SLA+1); //Send the slave address+1 (read address)
tmph = TWI_readByte(1); //Read data from TWI (high byte) ACK
tmpl = TWI_readByte(1); //Read data from TWI (low byte) ACK
TWI_Stop(); //Send the TWI Stop
tmp=tmph << 8; //Move the high byte into the high byte position
tmp=tmp+tmpl; //Add the low byte
return tmp; //Return the 16-bit value
}
*/
uint8_t readEM_Status(uint8_t SLA) {
uint8_t tmp; //The 8-bit value to return
TWI_Start(); //Send the TWI Start
TWI_sendByte(SLA); //Send the slave address (write address)
TWI_sendByte(0x03); //Send the address to read from
TWI_Start(); //Send a repeated start
TWI_sendByte(SLA+1); //Send the slave address+1 (read address)
tmp = TWI_readByte(0);
TWI_Stop(); //Send the TWI Stop
return tmp; //Return the 16-bit value
}
uint16_t readEM_CTRL(uint8_t SLA) {
uint16_t tmp; //The 16-bit value to return
TWI_Start(); //Send the TWI Start
TWI_sendByte(SLA); //Send the slave address (write address)
TWI_sendByte(0x00); //Send the address to read from
TWI_Start(); //Send a repeated start
TWI_sendByte(SLA+1); //Send the slave address+1 (read address)
tmp = (TWI_readByte(1)<<8); //Read data from TWI (high byte) ACK
tmp += TWI_readByte(0); //Read data from TWI (low byte) NACK
TWI_Stop(); //Send the TWI Stop
return tmp; //Return the 16-bit value
}
uint32_t readEM_Time(uint8_t SLA) {
uint32_t tmp=0; //The 32-bit value to return
TWI_Start(); //Send the TWI Start
TWI_sendByte(SLA); //Send the slave address (write address)
TWI_sendByte(0x34); //Send the address to read from
TWI_Start(); //Send a repeated start
TWI_sendByte(SLA+1); //Send the slave address+1 (read address)
tmp = TWI_readByte(1); //Read data from TWI (high byte 3) ACK
tmp = (tmp<<8) + TWI_readByte(1); //Read data from TWI (high byte 2) ACK
tmp = (tmp<<8) + TWI_readByte(1); //Read data from TWI (high byte 1) ACK
tmp = (tmp<<8) + TWI_readByte(0); //Read data from TWI (low byte) NACK
TWI_Stop(); //Send the TWI Stop
return tmp; //Return the 32-bit value
}
uint16_t readEM_VOLT(uint8_t SLA) {
uint16_t tmp; //The 16-bit value to return
TWI_Start(); //Send the TWI Start
TWI_sendByte(SLA); //Send the slave address (write address)
TWI_sendByte(0x1E); //Send the address to read from
TWI_Start(); //Send a repeated start
TWI_sendByte(SLA+1); //Send the slave address+1 (read address)
tmp = (TWI_readByte(1)<<4); //Read data from TWI (high byte) ACK
tmp += TWI_readByte(0)>>4; //Read data from TWI (low byte) NACK
TWI_Stop(); //Send the TWI Stop
return tmp; //Return the 16-bit value
}
uint16_t readEM_CURRENT(uint8_t SLA) {
uint16_t tmp; //The 16-bit value to return
TWI_Start(); //Send the TWI Start
TWI_sendByte(SLA); //Send the slave address (write address)
TWI_sendByte(0x14); //Send the address to read from
TWI_Start(); //Send a repeated start
TWI_sendByte(SLA+1); //Send the slave address+1 (read address)
tmp = (TWI_readByte(1)<<4); //Read data from TWI (high byte) ACK
tmp += TWI_readByte(0)>>4; //Read data from TWI (low byte) NACK
TWI_Stop(); //Send the TWI Stop
return tmp; //Return the 16-bit value
}
uint32_t readEM_POWER(uint8_t SLA) {
uint32_t tmp=0; //The 32-bit value to return
TWI_Start(); //Send the TWI Start
TWI_sendByte(SLA); //Send the slave address (write address)
TWI_sendByte(0x05); //Send the address to read from
TWI_Start(); //Send a repeated start
TWI_sendByte(SLA+1); //Send the slave address+1 (read address)
tmp = TWI_readByte(1); //Read data from TWI (high byte2) ACK
tmp = (tmp<<8) + TWI_readByte(1); //Read data from TWI (high byte1) ACK
tmp = (tmp<<8) + TWI_readByte(0); //Read data from TWI (low byte) NACK
TWI_Stop(); //Send the TWI Stop
return tmp; //Return the 32-bit value
}
uint32_t readEM_ENERGY(uint8_t SLA) {
uint32_t tmp; //The 16-bit value to return
TWI_Start(); //Send the TWI Start
TWI_sendByte(SLA); //Send the slave address (write address)
TWI_sendByte(0x3C); //Send the address to read from
TWI_Start(); //Send a repeated start
TWI_sendByte(SLA+1); //Send the slave address+1 (read address)
tmp = (TWI_readByte(1)*16777216); //Read data from TWI (high byte 3) ACK
tmp += (TWI_readByte(1)*65536); //Read data from TWI (high byte2) ACK
tmp += (TWI_readByte(1)<<8); //Read data from TWI (high byte1) ACK
tmp += TWI_readByte(0); //Read data from TWI (low byte) NACK
TWI_Stop(); //Send the TWI Stop
return tmp; //Return the 16-bit value
}
void sendEM_RESET_ACC(uint8_t SLA){
TWI_Start(); //Send the TWI Start
TWI_sendByte(SLA); //Send the slave address
TWI_sendByte(0x01); //Send the CTRLB Register Address
TWI_sendByte(0x02); //Send the reset accumulator command
TWI_Stop();
TWI_Start(); //Send the TWI Start
TWI_sendByte(SLA); //Send the slave address
TWI_sendByte(0x01); //Send the CTRLB Register Address
TWI_sendByte(0x00); //Send the reset accumulator command
}