From 3479830f597cb6dbdb8eb91454c235b58ef69cf1 Mon Sep 17 00:00:00 2001
From: Sam Calisch <s.calisch@gmail.com>
Date: Fri, 18 Aug 2017 16:56:05 -0400
Subject: [PATCH] started firmware
---
as5013-test/as5013-test.c | 97 +++++++
as5013-test/as5013-test.make | 19 ++
as5013-test/serial.h | 227 +++++++++++++++
as5013-test/twi_master_driver.c | 399 ++++++++++++++++++++++++++
as5013-test/twi_master_driver.h | 490 ++++++++++++++++++++++++++++++++
5 files changed, 1232 insertions(+)
create mode 100644 as5013-test/as5013-test.c
create mode 100644 as5013-test/as5013-test.make
create mode 100644 as5013-test/serial.h
create mode 100644 as5013-test/twi_master_driver.c
create mode 100644 as5013-test/twi_master_driver.h
diff --git a/as5013-test/as5013-test.c b/as5013-test/as5013-test.c
new file mode 100644
index 0000000..24390f8
--- /dev/null
+++ b/as5013-test/as5013-test.c
@@ -0,0 +1,97 @@
+//
+// xmega twi for as5013 2d linear magnetic encoder
+// sec, 2017
+
+#include "serial.h"
+#include <avr/io.h>
+#include <util/delay.h>
+#include <avr/pgmspace.h>
+#include <avr/interrupt.h>
+#include "twi_master_driver.h"
+
+#define SLAVE_ADDRESS 0x41
+#define CPU_SPEED 32000000
+#define TWI_BAUDRATE 100000
+#define TWI_BAUDSETTING TWI_BAUD(CPU_SPEED, TWI_BAUDRATE)
+TWI_Master_t twiMaster; /*!< TWI master module. */
+
+USART_data_t USART_data;
+
+uint32_t value; //magnetic encoder reading
+unsigned char Data_LSB, Data_MSB; //high byte and low byte of reading
+
+
+uint8_t address_data[2] = {0x00, 0x01};
+uint8_t speed_mode_data[2] = {0x02, 0x04}; //set into slow mode, value=4
+uint8_t sensitivity_mode_data[2] = {0x0B, 0x02}; //set into highest sensitivity value=2
+bool result = true;
+
+
+
+
+int main(void) {
+ // set up clock
+ OSC.CTRL = OSC_RC32MEN_bm; // enable 32MHz clock
+ while (!(OSC.STATUS & OSC_RC32MRDY_bm)); // wait for clock to be ready
+ CCP = CCP_IOREG_gc; // enable protected register change
+ CLK.CTRL = CLK_SCLKSEL_RC32M_gc; // switch to 32MHz clock
+
+ //set up usart
+ PORTD.DIRSET = PIN3_bm; //TXD0
+ PORTD.DIRCLR = PIN2_bm; //RXD0
+ USART_InterruptDriver_Initialize(&USART_data, &USARTD0, USART_DREINTLVL_LO_gc);
+ USART_Format_Set(USART_data.usart, USART_CHSIZE_8BIT_gc,
+ USART_PMODE_DISABLED_gc, 0);
+ USART_RxdInterruptLevel_Set(USART_data.usart, USART_RXCINTLVL_LO_gc);
+ //take f_sysclk/(BSEL+1) ~= f_baud*16 with zero scale. See manual or spreadsheet for scale defs
+ USART_Baudrate_Set(&USARTD0, 123 , -4); //230400 baud with .08% error
+ USART_Rx_Enable(USART_data.usart);
+ USART_Tx_Enable(USART_data.usart);
+ //enable interrupts
+ PMIC.CTRL |= PMIC_LOLVLEX_bm;
+
+ //set up twi
+ TWI_MasterInit(&twiMaster, &TWIC, TWI_MASTER_INTLVL_LO_gc, TWI_BAUDSETTING);
+ //PORTC.DIRCLR = PIN0_bm | PIN1_bm; //TXD0
+
+ sei();
+
+
+ //set as5013 speed mode
+ //result = TWI_MasterWrite(&twiMaster, SLAVE_ADDRESS, &speed_mode_data[0], 2);
+ //while (twiMaster.status != TWIM_STATUS_READY) {}
+
+ //set as5011 sensitivity
+ //result = TWI_MasterWrite(&twiMaster, SLAVE_ADDRESS, &sensitivity_mode_data[0],2);
+ //while (twiMaster.status != TWIM_STATUS_READY) {}
+
+
+ while(1){
+
+ result = TWI_MasterWriteRead(&twiMaster, SLAVE_ADDRESS, &address_data[0], 1,2); // Read D7..0
+ while (twiMaster.status != TWIM_STATUS_READY) {}
+ if (result) {
+ Data_LSB = twiMaster.readData[0];
+ Data_MSB = twiMaster.readData[1];
+
+ }
+ else { Data_LSB = 255; Data_MSB = 255;}
+
+ //value = ((Data_MSB & 0x03)<<8) + Data_LSB;
+
+ usart_send_byte(&USART_data,1);
+ usart_send_byte(&USART_data,2);
+ usart_send_byte(&USART_data,3);
+ usart_send_byte(&USART_data,4);
+ //usart_send_uint32(&USART_data,value);
+ usart_send_byte(&USART_data,Data_LSB);
+ //usart_send_byte(&USART_data,twiMaster.result);
+ usart_send_byte(&USART_data,(Data_MSB & 0x03));
+ usart_send_byte(&USART_data,10);
+ _delay_ms(100);
+ }
+}
+
+ISR(USARTD0_RXC_vect){USART_RXComplete(&USART_data);}
+ISR(USARTD0_DRE_vect){USART_DataRegEmpty(&USART_data);}
+ISR(TWIC_TWIM_vect){TWI_MasterInterruptHandler(&twiMaster);}
diff --git a/as5013-test/as5013-test.make b/as5013-test/as5013-test.make
new file mode 100644
index 0000000..e6a7fe2
--- /dev/null
+++ b/as5013-test/as5013-test.make
@@ -0,0 +1,19 @@
+PROJECT=as5013-test
+SOURCES=$(PROJECT).c
+MMCU=atxmega16e5
+F_CPU = 32000000
+TARGET = x16e5
+PROGRAMMER= atmelice_pdi
+
+CFLAGS=-mmcu=$(MMCU) -Wall -Os -DF_CPU=$(F_CPU)
+
+$(PROJECT).hex: $(PROJECT).out
+ avr-objcopy -O ihex $(PROJECT).out $(PROJECT).c.hex;\
+ avr-size --mcu=$(MMCU) --format=avr $(PROJECT).out
+
+$(PROJECT).out: $(SOURCES)
+ avr-gcc $(CFLAGS) -I./ -o $(PROJECT).out $(SOURCES)
+
+program: $(PROJECT).hex
+ avrdude -p $(TARGET) -c $(PROGRAMMER) -U flash:w:$(PROJECT).c.hex
+
diff --git a/as5013-test/serial.h b/as5013-test/serial.h
new file mode 100644
index 0000000..4d7312a
--- /dev/null
+++ b/as5013-test/serial.h
@@ -0,0 +1,227 @@
+#include <avr/io.h>
+#include <util/delay.h>
+#include <avr/pgmspace.h>
+
+#define output(directions,pin) (directions |= pin) // set port direction for output
+#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
+
+/* USART buffer defines. */
+/* \brief Receive buffer size: 2,4,8,16,32,64,128 or 256 bytes. */
+#define USART_RX_BUFFER_SIZE 128
+/* \brief Transmit buffer size: 2,4,8,16,32,64,128 or 256 bytes */
+#define USART_TX_BUFFER_SIZE 128
+/* \brief Receive buffer mask. */
+#define USART_RX_BUFFER_MASK ( USART_RX_BUFFER_SIZE - 1 )
+/* \brief Transmit buffer mask. */
+#define USART_TX_BUFFER_MASK ( USART_TX_BUFFER_SIZE - 1 )
+
+#if ( USART_RX_BUFFER_SIZE & USART_RX_BUFFER_MASK )
+#error RX buffer size is not a power of 2
+#endif
+#if ( USART_TX_BUFFER_SIZE & USART_TX_BUFFER_MASK )
+#error TX buffer size is not a power of 2
+#endif
+
+/* \brief USART transmit and receive ring buffer. */
+typedef struct USART_Buffer
+{
+ /* \brief Receive buffer. */
+ volatile uint8_t RX[USART_RX_BUFFER_SIZE];
+ /* \brief Transmit buffer. */
+ volatile uint8_t TX[USART_TX_BUFFER_SIZE];
+ /* \brief Receive buffer head. */
+ volatile uint8_t RX_Head;
+ /* \brief Receive buffer tail. */
+ volatile uint8_t RX_Tail;
+ /* \brief Transmit buffer head. */
+ volatile uint8_t TX_Head;
+ /* \brief Transmit buffer tail. */
+ volatile uint8_t TX_Tail;
+} USART_Buffer_t;
+
+
+/*! \brief Struct used when interrupt driven driver is used.
+*
+* Struct containing pointer to a usart, a buffer and a location to store Data
+* register interrupt level temporary.
+*/
+typedef struct Usart_and_buffer
+{
+ /* \brief Pointer to USART module to use. */
+ USART_t * usart;
+ /* \brief Data register empty interrupt level. */
+ USART_DREINTLVL_t dreIntLevel;
+ /* \brief Data buffer. */
+ USART_Buffer_t buffer;
+} USART_data_t;
+
+#define USART_RxdInterruptLevel_Set(_usart, _rxdIntLevel) \
+ ((_usart)->CTRLA = ((_usart)->CTRLA & ~USART_RXCINTLVL_gm) | _rxdIntLevel)
+#define USART_Format_Set(_usart, _charSize, _parityMode, _twoStopBits) \
+ (_usart)->CTRLC = (uint8_t) _charSize | _parityMode | \
+ (_twoStopBits ? USART_SBMODE_bm : 0)
+#define USART_Baudrate_Set(_usart, _bselValue, _bScaleFactor) \
+ (_usart)->BAUDCTRLA =(uint8_t)_bselValue; \
+ (_usart)->BAUDCTRLB =(_bScaleFactor << USART_BSCALE0_bp)|(_bselValue >> 8)
+#define USART_Rx_Enable(_usart) ((_usart)->CTRLB |= USART_RXEN_bm)
+#define USART_Rx_Disable(_usart) ((_usart)->CTRLB &= ~USART_RXEN_bm)
+#define USART_Tx_Enable(_usart) ((_usart)->CTRLB |= USART_TXEN_bm)
+#define USART_Tx_Disable(_usart) ((_usart)->CTRLB &= ~USART_TXEN_bm)
+
+
+
+_Bool USART_TXBuffer_FreeSpace(USART_data_t * usart_data)
+{
+ /* Make copies to make sure that volatile access is specified. */
+ uint8_t tempHead = (usart_data->buffer.TX_Head + 1) & USART_TX_BUFFER_MASK;
+ uint8_t tempTail = usart_data->buffer.TX_Tail;
+
+ /* There are data left in the buffer unless Head and Tail are equal. */
+ return (tempHead != tempTail);
+}
+_Bool USART_TXBuffer_PutByte(USART_data_t * usart_data, uint8_t data)
+{
+ uint8_t tempCTRLA;
+ uint8_t tempTX_Head;
+ _Bool TXBuffer_FreeSpace;
+ USART_Buffer_t * TXbufPtr;
+
+ TXbufPtr = &usart_data->buffer;
+ TXBuffer_FreeSpace = USART_TXBuffer_FreeSpace(usart_data);
+
+
+ if(TXBuffer_FreeSpace)
+ {
+ tempTX_Head = TXbufPtr->TX_Head;
+ TXbufPtr->TX[tempTX_Head]= data;
+ /* Advance buffer head. */
+ TXbufPtr->TX_Head = (tempTX_Head + 1) & USART_TX_BUFFER_MASK;
+
+ /* Enable DRE interrupt. */
+ tempCTRLA = usart_data->usart->CTRLA;
+ tempCTRLA = (tempCTRLA & ~USART_DREINTLVL_gm) | usart_data->dreIntLevel;
+ usart_data->usart->CTRLA = tempCTRLA;
+ }
+ return TXBuffer_FreeSpace;
+}
+_Bool USART_RXBufferData_Available(USART_data_t * usart_data)
+{
+ /* Make copies to make sure that volatile access is specified. */
+ uint8_t tempHead = usart_data->buffer.RX_Head;
+ uint8_t tempTail = usart_data->buffer.RX_Tail;
+
+ /* There are data left in the buffer unless Head and Tail are equal. */
+ return (tempHead != tempTail);
+}
+uint8_t USART_RXBuffer_GetByte(USART_data_t * usart_data)
+{
+ USART_Buffer_t * bufPtr;
+ uint8_t ans;
+ bufPtr = &usart_data->buffer;
+ ans = (bufPtr->RX[bufPtr->RX_Tail]);
+
+ /* Advance buffer tail. */
+ bufPtr->RX_Tail = (bufPtr->RX_Tail + 1) & USART_RX_BUFFER_MASK;
+ return ans;
+}
+_Bool USART_RXComplete(USART_data_t * usart_data)
+{
+ USART_Buffer_t * bufPtr;
+ _Bool ans;
+
+ bufPtr = &usart_data->buffer;
+ /* Advance buffer head. */
+ uint8_t tempRX_Head = (bufPtr->RX_Head + 1) & USART_RX_BUFFER_MASK;
+
+ /* Check for overflow. */
+ uint8_t tempRX_Tail = bufPtr->RX_Tail;
+ uint8_t data = usart_data->usart->DATA;
+
+ if (tempRX_Head == tempRX_Tail) {
+ ans = 0;
+ }else{
+ ans = 1;
+ usart_data->buffer.RX[usart_data->buffer.RX_Head] = data;
+ usart_data->buffer.RX_Head = tempRX_Head;
+ }
+ return ans;
+}
+void USART_DataRegEmpty(USART_data_t * usart_data)
+{
+ USART_Buffer_t * bufPtr;
+ bufPtr = &usart_data->buffer;
+
+ /* Check if all data is transmitted. */
+ uint8_t tempTX_Tail = usart_data->buffer.TX_Tail;
+ if (bufPtr->TX_Head == tempTX_Tail){
+ /* Disable DRE interrupts. */
+ uint8_t tempCTRLA = usart_data->usart->CTRLA;
+ tempCTRLA = (tempCTRLA & ~USART_DREINTLVL_gm) | USART_DREINTLVL_OFF_gc;
+ usart_data->usart->CTRLA = tempCTRLA;
+
+ }else{
+ /* Start transmitting. */
+ uint8_t data = bufPtr->TX[usart_data->buffer.TX_Tail];
+ usart_data->usart->DATA = data;
+
+ /* Advance buffer tail. */
+ bufPtr->TX_Tail = (bufPtr->TX_Tail + 1) & USART_TX_BUFFER_MASK;
+ }
+}
+void USART_InterruptDriver_Initialize(USART_data_t * usart_data,
+ USART_t * usart,
+ USART_DREINTLVL_t dreIntLevel)
+{
+ usart_data->usart = usart;
+ usart_data->dreIntLevel = dreIntLevel;
+
+ usart_data->buffer.RX_Tail = 0;
+ usart_data->buffer.RX_Head = 0;
+ usart_data->buffer.TX_Tail = 0;
+ usart_data->buffer.TX_Head = 0;
+}
+void USART_InterruptDriver_DreInterruptLevel_Set(USART_data_t * usart_data,
+ USART_DREINTLVL_t dreIntLevel)
+{
+ usart_data->dreIntLevel = dreIntLevel;
+}
+
+void usart_send_byte(USART_data_t * usart_data, char msg){
+ while(!USART_TXBuffer_FreeSpace(usart_data)){}
+ USART_TXBuffer_PutByte(usart_data,msg);
+}
+void usart_send_uint32(USART_data_t * usart_data, uint32_t n){
+ unsigned char * nn = (unsigned char *)&n;
+ usart_send_byte(usart_data, nn[0] );
+ usart_send_byte(usart_data, nn[1] );
+ usart_send_byte(usart_data, nn[2] );
+ usart_send_byte(usart_data, nn[3] );
+}
+void usart_send_int32(USART_data_t * usart_data, int32_t n){
+ unsigned char * nn = ( unsigned char *)&n;
+ usart_send_byte(usart_data, nn[0] );
+ usart_send_byte(usart_data, nn[1] );
+ usart_send_byte(usart_data, nn[2] );
+ usart_send_byte(usart_data, nn[3] );
+}
+uint32_t parse_uint32(char* b){return *(uint32_t *) b;}
+int32_t parse_int32(char* b){return *(int32_t *) b;}
+uint16_t parse_uint16(char* b){return *(uint16_t *) b;}
+
+
+/*
+void usart_write_buffer(char* buffer){
+ //write \n terminated buffer over usart
+ int j=0;
+ do{
+ usart_send_byte( buffer[j] );
+ j++;
+ } while( j < PACKET_SIZE);
+ //} while( buffer[j-1] != 10);
+}
+*/
+
+
diff --git a/as5013-test/twi_master_driver.c b/as5013-test/twi_master_driver.c
new file mode 100644
index 0000000..c7f9695
--- /dev/null
+++ b/as5013-test/twi_master_driver.c
@@ -0,0 +1,399 @@
+/* This file has been prepared for Doxygen automatic documentation generation.*/
+/*! \file *********************************************************************
+ *
+ * \brief
+ * XMEGA TWI master driver source file.
+ *
+ * This file contains the function implementations the XMEGA master TWI
+ * driver.
+ *
+ * The driver is not intended for size and/or speed critical code, since
+ * most functions are just a few lines of code, and the function call
+ * overhead would decrease code performance. The driver is intended for
+ * rapid prototyping and documentation purposes for getting started with
+ * the XMEGA TWI master module.
+ *
+ * For size and/or speed critical code, it is recommended to copy the
+ * function contents directly into your application instead of making
+ * a function call.
+ *
+ * Several functions use the following construct:
+ * "some_register = ... | (some_parameter ? SOME_BIT_bm : 0) | ..."
+ * Although the use of the ternary operator ( if ? then : else ) is
+ * discouraged, in some occasions the operator makes it possible to write
+ * pretty clean and neat code. In this driver, the construct is used to
+ * set or not set a configuration bit based on a boolean input parameter,
+ * such as the "some_parameter" in the example above.
+ *
+ * \par Application note:
+ * AVR1308: Using the XMEGA TWI
+ *
+ * \par Documentation
+ * For comprehensive code documentation, supported compilers, compiler
+ * settings and supported devices see readme.html
+ *
+ * \author
+ * Atmel Corporation: http://www.atmel.com \n
+ * Support email: avr@atmel.com
+ *
+ * $Revision: 1569 $
+ * $Date: 2008-04-22 13:03:43 +0200 (ti, 22 apr 2008) $ \n
+ *
+ * Copyright (c) 2008, Atmel Corporation All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3. The name of ATMEL may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY AND
+ * SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *****************************************************************************/
+
+#include "twi_master_driver.h"
+
+
+/*! \brief Initialize the TWI module.
+ *
+ * TWI module initialization function.
+ * Enables master read and write interrupts.
+ * Remember to enable interrupts globally from the main application.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ * \param module The TWI module to use.
+ * \param intLevel Master interrupt level.
+ * \param baudRateRegisterSetting The baud rate register value.
+ */
+void TWI_MasterInit(TWI_Master_t *twi,
+ TWI_t *module,
+ TWI_MASTER_INTLVL_t intLevel,
+ uint8_t baudRateRegisterSetting)
+{
+ twi->interface = module;
+ twi->interface->MASTER.CTRLA = intLevel |
+ TWI_MASTER_RIEN_bm |
+ TWI_MASTER_WIEN_bm |
+ TWI_MASTER_ENABLE_bm;
+ twi->interface->MASTER.BAUD = baudRateRegisterSetting;
+ twi->interface->MASTER.STATUS = TWI_MASTER_BUSSTATE_IDLE_gc;
+}
+
+
+/*! \brief Returns the TWI bus state.
+ *
+ * Returns the TWI bus state (type defined in device headerfile),
+ * unknown, idle, owner or busy.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ *
+ * \retval TWI_MASTER_BUSSTATE_UNKNOWN_gc Bus state is unknown.
+ * \retval TWI_MASTER_BUSSTATE_IDLE_gc Bus state is idle.
+ * \retval TWI_MASTER_BUSSTATE_OWNER_gc Bus state is owned by the master.
+ * \retval TWI_MASTER_BUSSTATE_BUSY_gc Bus state is busy.
+ */
+TWI_MASTER_BUSSTATE_t TWI_MasterState(TWI_Master_t *twi)
+{
+ TWI_MASTER_BUSSTATE_t twi_status;
+ twi_status = (TWI_MASTER_BUSSTATE_t) (twi->interface->MASTER.STATUS &
+ TWI_MASTER_BUSSTATE_gm);
+ return twi_status;
+}
+
+
+/*! \brief Returns true if transaction is ready.
+ *
+ * This function returns a boolean whether the TWI Master is ready
+ * for a new transaction.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ *
+ * \retval true If transaction could be started.
+ * \retval false If transaction could not be started.
+ */
+bool TWI_MasterReady(TWI_Master_t *twi)
+{
+ bool twi_status = (twi->status & TWIM_STATUS_READY);
+ return twi_status;
+}
+
+
+/*! \brief TWI write transaction.
+ *
+ * This function is TWI Master wrapper for a write-only transaction.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ * \param address Slave address.
+ * \param writeData Pointer to data to write.
+ * \param bytesToWrite Number of data bytes to write.
+ *
+ * \retval true If transaction could be started.
+ * \retval false If transaction could not be started.
+ */
+bool TWI_MasterWrite(TWI_Master_t *twi,
+ uint8_t address,
+ uint8_t *writeData,
+ uint8_t bytesToWrite)
+{
+ bool twi_status = TWI_MasterWriteRead(twi, address, writeData, bytesToWrite, 0);
+ return twi_status;
+}
+
+
+/*! \brief TWI read transaction.
+ *
+ * This function is a TWI Maste wrapper for read-only transaction.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ * \param address The slave address.
+ * \param bytesToRead The number of bytes to read.
+ *
+ * \retval true If transaction could be started.
+ * \retval false If transaction could not be started.
+ */
+bool TWI_MasterRead(TWI_Master_t *twi,
+ uint8_t address,
+ uint8_t bytesToRead)
+{
+ bool twi_status = TWI_MasterWriteRead(twi, address, 0, 0, bytesToRead);
+ return twi_status;
+}
+
+
+/*! \brief TWI write and/or read transaction.
+ *
+ * This function is a TWI Master write and/or read transaction. The function
+ * can be used to both write and/or read bytes to/from the TWI Slave in one
+ * transaction.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ * \param address The slave address.
+ * \param writeData Pointer to data to write.
+ * \param bytesToWrite Number of bytes to write.
+ * \param bytesToRead Number of bytes to read.
+ *
+ * \retval true If transaction could be started.
+ * \retval false If transaction could not be started.
+ */
+bool TWI_MasterWriteRead(TWI_Master_t *twi,
+ uint8_t address,
+ uint8_t *writeData,
+ uint8_t bytesToWrite,
+ uint8_t bytesToRead)
+{
+ /*Parameter sanity check. */
+ if (bytesToWrite > TWIM_WRITE_BUFFER_SIZE) {
+ return false;
+ }
+ if (bytesToRead > TWIM_READ_BUFFER_SIZE) {
+ return false;
+ }
+
+ /*Initiate transaction if bus is ready. */
+ if (twi->status == TWIM_STATUS_READY) {
+
+ twi->status = TWIM_STATUS_BUSY;
+ twi->result = TWIM_RESULT_UNKNOWN;
+
+ twi->address = address<<1;
+
+ /* Fill write data buffer. */
+ for (uint8_t bufferIndex=0; bufferIndex < bytesToWrite; bufferIndex++) {
+ twi->writeData[bufferIndex] = writeData[bufferIndex];
+ }
+
+ twi->bytesToWrite = bytesToWrite;
+ twi->bytesToRead = bytesToRead;
+ twi->bytesWritten = 0;
+ twi->bytesRead = 0;
+
+ /* If write command, send the START condition + Address +
+ * 'R/_W = 0'
+ */
+ if (twi->bytesToWrite > 0) {
+ uint8_t writeAddress = twi->address & ~0x01;
+ twi->interface->MASTER.ADDR = writeAddress;
+ }
+
+ /* If read command, send the START condition + Address +
+ * 'R/_W = 1'
+ */
+ else if (twi->bytesToRead > 0) {
+ uint8_t readAddress = twi->address | 0x01;
+ twi->interface->MASTER.ADDR = readAddress;
+ }
+ return true;
+ } else {
+ return false;
+ }
+}
+
+
+/*! \brief Common TWI master interrupt service routine.
+ *
+ * Check current status and calls the appropriate handler.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ */
+void TWI_MasterInterruptHandler(TWI_Master_t *twi)
+{
+ uint8_t currentStatus = twi->interface->MASTER.STATUS;
+
+ /* If arbitration lost or bus error. */
+ if ((currentStatus & TWI_MASTER_ARBLOST_bm) ||
+ (currentStatus & TWI_MASTER_BUSERR_bm)) {
+
+ TWI_MasterArbitrationLostBusErrorHandler(twi);
+ }
+
+ /* If master write interrupt. */
+ else if (currentStatus & TWI_MASTER_WIF_bm) {
+ TWI_MasterWriteHandler(twi);
+ }
+
+ /* If master read interrupt. */
+ else if (currentStatus & TWI_MASTER_RIF_bm) {
+ TWI_MasterReadHandler(twi);
+ }
+
+ /* If unexpected state. */
+ else {
+ TWI_MasterTransactionFinished(twi, TWIM_RESULT_FAIL);
+ }
+}
+
+
+/*! \brief TWI master arbitration lost and bus error interrupt handler.
+ *
+ * Handles TWI responses to lost arbitration and bus error.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ */
+void TWI_MasterArbitrationLostBusErrorHandler(TWI_Master_t *twi)
+{
+ uint8_t currentStatus = twi->interface->MASTER.STATUS;
+
+ /* If bus error. */
+ if (currentStatus & TWI_MASTER_BUSERR_bm) {
+ twi->result = TWIM_RESULT_BUS_ERROR;
+ }
+ /* If arbitration lost. */
+ else {
+ twi->result = TWIM_RESULT_ARBITRATION_LOST;
+ }
+
+ /* Clear interrupt flag. */
+ twi->interface->MASTER.STATUS = currentStatus | TWI_MASTER_ARBLOST_bm;
+
+ twi->status = TWIM_STATUS_READY;
+}
+
+
+/*! \brief TWI master write interrupt handler.
+ *
+ * Handles TWI transactions (master write) and responses to (N)ACK.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ */
+void TWI_MasterWriteHandler(TWI_Master_t *twi)
+{
+ /* Local variables used in if tests to avoid compiler warning. */
+ uint8_t bytesToWrite = twi->bytesToWrite;
+ uint8_t bytesToRead = twi->bytesToRead;
+
+ /* If NOT acknowledged (NACK) by slave cancel the transaction. */
+ if (twi->interface->MASTER.STATUS & TWI_MASTER_RXACK_bm) {
+ twi->interface->MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
+ twi->result = TWIM_RESULT_NACK_RECEIVED;
+ twi->status = TWIM_STATUS_READY;
+ }
+
+ /* If more bytes to write, send data. */
+ else if (twi->bytesWritten < bytesToWrite) {
+ uint8_t data = twi->writeData[twi->bytesWritten];
+ twi->interface->MASTER.DATA = data;
+ ++twi->bytesWritten;
+ }
+
+ /* If bytes to read, send repeated START condition + Address +
+ * 'R/_W = 1'
+ */
+ else if (twi->bytesRead < bytesToRead) {
+ uint8_t readAddress = twi->address | 0x01;
+ twi->interface->MASTER.ADDR = readAddress;
+ }
+
+ /* If transaction finished, send STOP condition and set RESULT OK. */
+ else {
+ twi->interface->MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
+ TWI_MasterTransactionFinished(twi, TWIM_RESULT_OK);
+ }
+}
+
+
+/*! \brief TWI master read interrupt handler.
+ *
+ * This is the master read interrupt handler that takes care of
+ * reading bytes from the TWI slave.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ */
+void TWI_MasterReadHandler(TWI_Master_t *twi)
+{
+ /* Fetch data if bytes to be read. */
+ if (twi->bytesRead < TWIM_READ_BUFFER_SIZE) {
+ uint8_t data = twi->interface->MASTER.DATA;
+ twi->readData[twi->bytesRead] = data;
+ twi->bytesRead++;
+ }
+
+ /* If buffer overflow, issue STOP and BUFFER_OVERFLOW condition. */
+ else {
+ twi->interface->MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
+ TWI_MasterTransactionFinished(twi, TWIM_RESULT_BUFFER_OVERFLOW);
+ }
+
+ /* Local variable used in if test to avoid compiler warning. */
+ uint8_t bytesToRead = twi->bytesToRead;
+
+ /* If more bytes to read, issue ACK and start a byte read. */
+ if (twi->bytesRead < bytesToRead) {
+ twi->interface->MASTER.CTRLC = TWI_MASTER_CMD_RECVTRANS_gc;
+ }
+
+ /* If transaction finished, issue NACK and STOP condition. */
+ else {
+ twi->interface->MASTER.CTRLC = TWI_MASTER_ACKACT_bm |
+ TWI_MASTER_CMD_STOP_gc;
+ TWI_MasterTransactionFinished(twi, TWIM_RESULT_OK);
+ }
+}
+
+
+/*! \brief TWI transaction finished handler.
+ *
+ * Prepares module for new transaction.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ * \param result The result of the operation.
+ */
+void TWI_MasterTransactionFinished(TWI_Master_t *twi, uint8_t result)
+{
+ twi->result = result;
+ twi->status = TWIM_STATUS_READY;
+}
diff --git a/as5013-test/twi_master_driver.h b/as5013-test/twi_master_driver.h
new file mode 100644
index 0000000..3d4dd06
--- /dev/null
+++ b/as5013-test/twi_master_driver.h
@@ -0,0 +1,490 @@
+/* This file has been prepared for Doxygen automatic documentation generation.*/
+/*! \file *********************************************************************
+ *
+ * \brief XMEGA TWI master driver header file.
+ *
+ * This file contains the function prototypes and enumerator definitions
+ * for various configuration parameters for the XMEGA TWI master driver.
+ *
+ * The driver is not intended for size and/or speed critical code, since
+ * most functions are just a few lines of code, and the function call
+ * overhead would decrease code performance. The driver is intended for
+ * rapid prototyping and documentation purposes for getting started with
+ * the XMEGA TWI master module.
+ *
+ * For size and/or speed critical code, it is recommended to copy the
+ * function contents directly into your application instead of making
+ * a function call.
+ *
+ * \par Application note:
+ * AVR1308: Using the XMEGA TWI
+ *
+ * \par Documentation
+ * For comprehensive code documentation, supported compilers, compiler
+ * settings and supported devices see readme.html
+ *
+ * \author
+ * Atmel Corporation: http://www.atmel.com \n
+ * Support email: avr@atmel.com
+ *
+ * $Revision: 1569 $
+ * $Date: 2008-04-22 13:03:43 +0200 (ti, 22 apr 2008) $ \n
+ *
+ * Copyright (c) 2008, Atmel Corporation All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3. The name of ATMEL may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY AND
+ * SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *****************************************************************************/
+#ifndef TWI_MASTER_DRIVER_H
+#define TWI_MASTER_DRIVER_H
+
+#include "avr_compiler.h"
+
+/*! Baud register setting calculation. Formula described in datasheet. */
+#define TWI_BAUD(F_SYS, F_TWI) ((F_SYS / (2 * F_TWI)) - 5)
+
+
+/*! Transaction status defines. */
+#define TWIM_STATUS_READY 0
+#define TWIM_STATUS_BUSY 1
+
+
+/*! Transaction result enumeration. */
+typedef enum TWIM_RESULT_enum {
+ TWIM_RESULT_UNKNOWN = (0x00<<0),
+ TWIM_RESULT_OK = (0x01<<0),
+ TWIM_RESULT_BUFFER_OVERFLOW = (0x02<<0),
+ TWIM_RESULT_ARBITRATION_LOST = (0x03<<0),
+ TWIM_RESULT_BUS_ERROR = (0x04<<0),
+ TWIM_RESULT_NACK_RECEIVED = (0x05<<0),
+ TWIM_RESULT_FAIL = (0x06<<0),
+} TWIM_RESULT_t;
+
+/*! Buffer size defines */
+#define TWIM_WRITE_BUFFER_SIZE 8
+#define TWIM_READ_BUFFER_SIZE 8
+
+
+/*! \brief TWI master driver struct
+ *
+ * TWI master struct. Holds pointer to TWI module,
+ * buffers and necessary varibles.
+ */
+typedef struct TWI_Master {
+ TWI_t *interface; /*!< Pointer to what interface to use */
+ register8_t address; /*!< Slave address */
+ register8_t writeData[TWIM_WRITE_BUFFER_SIZE]; /*!< Data to write */
+ register8_t readData[TWIM_READ_BUFFER_SIZE]; /*!< Read data */
+ register8_t bytesToWrite; /*!< Number of bytes to write */
+ register8_t bytesToRead; /*!< Number of bytes to read */
+ register8_t bytesWritten; /*!< Number of bytes written */
+ register8_t bytesRead; /*!< Number of bytes read */
+ register8_t status; /*!< Status of transaction */
+ register8_t result; /*!< Result of transaction */
+}TWI_Master_t;
+
+
+
+void TWI_MasterInit(TWI_Master_t *twi,
+ TWI_t *module,
+ TWI_MASTER_INTLVL_t intLevel,
+ uint8_t baudRateRegisterSetting);
+TWI_MASTER_BUSSTATE_t TWI_MasterState(TWI_Master_t *twi);
+bool TWI_MasterReady(TWI_Master_t *twi);
+bool TWI_MasterWrite(TWI_Master_t *twi,
+ uint8_t address,
+ uint8_t * writeData,
+ uint8_t bytesToWrite);
+bool TWI_MasterRead(TWI_Master_t *twi,
+ uint8_t address,
+ uint8_t bytesToRead);
+bool TWI_MasterWriteRead(TWI_Master_t *twi,
+ uint8_t address,
+ uint8_t *writeData,
+ uint8_t bytesToWrite,
+ uint8_t bytesToRead);
+void TWI_MasterInterruptHandler(TWI_Master_t *twi);
+void TWI_MasterArbitrationLostBusErrorHandler(TWI_Master_t *twi);
+void TWI_MasterWriteHandler(TWI_Master_t *twi);
+void TWI_MasterReadHandler(TWI_Master_t *twi);
+void TWI_MasterTransactionFinished(TWI_Master_t *twi, uint8_t result);
+
+
+/*! TWI master interrupt service routine.
+ *
+ * Interrupt service routine for the TWI master. Copy the needed vectors
+ * into your code.
+ *
+ ISR(TWIC_TWIM_vect)
+ {
+ TWI_MasterInterruptHandler(&twiMaster);
+ }
+
+ *
+ */
+
+
+
+
+
+/*! \brief Initialize the TWI module.
+ *
+ * TWI module initialization function.
+ * Enables master read and write interrupts.
+ * Remember to enable interrupts globally from the main application.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ * \param module The TWI module to use.
+ * \param intLevel Master interrupt level.
+ * \param baudRateRegisterSetting The baud rate register value.
+ */
+void TWI_MasterInit(TWI_Master_t *twi,
+ TWI_t *module,
+ TWI_MASTER_INTLVL_t intLevel,
+ uint8_t baudRateRegisterSetting)
+{
+ twi->interface = module;
+ twi->interface->MASTER.CTRLA = intLevel |
+ TWI_MASTER_RIEN_bm |
+ TWI_MASTER_WIEN_bm |
+ TWI_MASTER_ENABLE_bm;
+ twi->interface->MASTER.BAUD = baudRateRegisterSetting;
+ twi->interface->MASTER.STATUS = TWI_MASTER_BUSSTATE_IDLE_gc;
+}
+
+
+/*! \brief Returns the TWI bus state.
+ *
+ * Returns the TWI bus state (type defined in device headerfile),
+ * unknown, idle, owner or busy.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ *
+ * \retval TWI_MASTER_BUSSTATE_UNKNOWN_gc Bus state is unknown.
+ * \retval TWI_MASTER_BUSSTATE_IDLE_gc Bus state is idle.
+ * \retval TWI_MASTER_BUSSTATE_OWNER_gc Bus state is owned by the master.
+ * \retval TWI_MASTER_BUSSTATE_BUSY_gc Bus state is busy.
+ */
+TWI_MASTER_BUSSTATE_t TWI_MasterState(TWI_Master_t *twi)
+{
+ TWI_MASTER_BUSSTATE_t twi_status;
+ twi_status = (TWI_MASTER_BUSSTATE_t) (twi->interface->MASTER.STATUS &
+ TWI_MASTER_BUSSTATE_gm);
+ return twi_status;
+}
+
+
+/*! \brief Returns true if transaction is ready.
+ *
+ * This function returns a boolean whether the TWI Master is ready
+ * for a new transaction.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ *
+ * \retval true If transaction could be started.
+ * \retval false If transaction could not be started.
+ */
+bool TWI_MasterReady(TWI_Master_t *twi)
+{
+ bool twi_status = (twi->status & TWIM_STATUS_READY);
+ return twi_status;
+}
+
+
+/*! \brief TWI write transaction.
+ *
+ * This function is TWI Master wrapper for a write-only transaction.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ * \param address Slave address.
+ * \param writeData Pointer to data to write.
+ * \param bytesToWrite Number of data bytes to write.
+ *
+ * \retval true If transaction could be started.
+ * \retval false If transaction could not be started.
+ */
+bool TWI_MasterWrite(TWI_Master_t *twi,
+ uint8_t address,
+ uint8_t *writeData,
+ uint8_t bytesToWrite)
+{
+ bool twi_status = TWI_MasterWriteRead(twi, address, writeData, bytesToWrite, 0);
+ return twi_status;
+}
+
+
+/*! \brief TWI read transaction.
+ *
+ * This function is a TWI Maste wrapper for read-only transaction.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ * \param address The slave address.
+ * \param bytesToRead The number of bytes to read.
+ *
+ * \retval true If transaction could be started.
+ * \retval false If transaction could not be started.
+ */
+bool TWI_MasterRead(TWI_Master_t *twi,
+ uint8_t address,
+ uint8_t bytesToRead)
+{
+ bool twi_status = TWI_MasterWriteRead(twi, address, 0, 0, bytesToRead);
+ return twi_status;
+}
+
+
+/*! \brief TWI write and/or read transaction.
+ *
+ * This function is a TWI Master write and/or read transaction. The function
+ * can be used to both write and/or read bytes to/from the TWI Slave in one
+ * transaction.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ * \param address The slave address.
+ * \param writeData Pointer to data to write.
+ * \param bytesToWrite Number of bytes to write.
+ * \param bytesToRead Number of bytes to read.
+ *
+ * \retval true If transaction could be started.
+ * \retval false If transaction could not be started.
+ */
+bool TWI_MasterWriteRead(TWI_Master_t *twi,
+ uint8_t address,
+ uint8_t *writeData,
+ uint8_t bytesToWrite,
+ uint8_t bytesToRead)
+{
+ /*Parameter sanity check. */
+ if (bytesToWrite > TWIM_WRITE_BUFFER_SIZE) {
+ return false;
+ }
+ if (bytesToRead > TWIM_READ_BUFFER_SIZE) {
+ return false;
+ }
+
+ /*Initiate transaction if bus is ready. */
+ if (twi->status == TWIM_STATUS_READY) {
+
+ twi->status = TWIM_STATUS_BUSY;
+ twi->result = TWIM_RESULT_UNKNOWN;
+
+ twi->address = address<<1;
+
+ /* Fill write data buffer. */
+ for (uint8_t bufferIndex=0; bufferIndex < bytesToWrite; bufferIndex++) {
+ twi->writeData[bufferIndex] = writeData[bufferIndex];
+ }
+
+ twi->bytesToWrite = bytesToWrite;
+ twi->bytesToRead = bytesToRead;
+ twi->bytesWritten = 0;
+ twi->bytesRead = 0;
+
+ /* If write command, send the START condition + Address +
+ * 'R/_W = 0'
+ */
+ if (twi->bytesToWrite > 0) {
+ uint8_t writeAddress = twi->address & ~0x01;
+ twi->interface->MASTER.ADDR = writeAddress;
+ }
+
+ /* If read command, send the START condition + Address +
+ * 'R/_W = 1'
+ */
+ else if (twi->bytesToRead > 0) {
+ uint8_t readAddress = twi->address | 0x01;
+ twi->interface->MASTER.ADDR = readAddress;
+ }
+ return true;
+ } else {
+ return false;
+ }
+}
+
+
+/*! \brief Common TWI master interrupt service routine.
+ *
+ * Check current status and calls the appropriate handler.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ */
+void TWI_MasterInterruptHandler(TWI_Master_t *twi)
+{
+ uint8_t currentStatus = twi->interface->MASTER.STATUS;
+
+ /* If arbitration lost or bus error. */
+ if ((currentStatus & TWI_MASTER_ARBLOST_bm) ||
+ (currentStatus & TWI_MASTER_BUSERR_bm)) {
+
+ TWI_MasterArbitrationLostBusErrorHandler(twi);
+ }
+
+ /* If master write interrupt. */
+ else if (currentStatus & TWI_MASTER_WIF_bm) {
+ TWI_MasterWriteHandler(twi);
+ }
+
+ /* If master read interrupt. */
+ else if (currentStatus & TWI_MASTER_RIF_bm) {
+ TWI_MasterReadHandler(twi);
+ }
+
+ /* If unexpected state. */
+ else {
+ TWI_MasterTransactionFinished(twi, TWIM_RESULT_FAIL);
+ }
+}
+
+
+/*! \brief TWI master arbitration lost and bus error interrupt handler.
+ *
+ * Handles TWI responses to lost arbitration and bus error.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ */
+void TWI_MasterArbitrationLostBusErrorHandler(TWI_Master_t *twi)
+{
+ uint8_t currentStatus = twi->interface->MASTER.STATUS;
+
+ /* If bus error. */
+ if (currentStatus & TWI_MASTER_BUSERR_bm) {
+ twi->result = TWIM_RESULT_BUS_ERROR;
+ }
+ /* If arbitration lost. */
+ else {
+ twi->result = TWIM_RESULT_ARBITRATION_LOST;
+ }
+
+ /* Clear interrupt flag. */
+ twi->interface->MASTER.STATUS = currentStatus | TWI_MASTER_ARBLOST_bm;
+
+ twi->status = TWIM_STATUS_READY;
+}
+
+
+/*! \brief TWI master write interrupt handler.
+ *
+ * Handles TWI transactions (master write) and responses to (N)ACK.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ */
+void TWI_MasterWriteHandler(TWI_Master_t *twi)
+{
+ /* Local variables used in if tests to avoid compiler warning. */
+ uint8_t bytesToWrite = twi->bytesToWrite;
+ uint8_t bytesToRead = twi->bytesToRead;
+
+ /* If NOT acknowledged (NACK) by slave cancel the transaction. */
+ if (twi->interface->MASTER.STATUS & TWI_MASTER_RXACK_bm) {
+ twi->interface->MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
+ twi->result = TWIM_RESULT_NACK_RECEIVED;
+ twi->status = TWIM_STATUS_READY;
+ }
+
+ /* If more bytes to write, send data. */
+ else if (twi->bytesWritten < bytesToWrite) {
+ uint8_t data = twi->writeData[twi->bytesWritten];
+ twi->interface->MASTER.DATA = data;
+ ++twi->bytesWritten;
+ }
+
+ /* If bytes to read, send repeated START condition + Address +
+ * 'R/_W = 1'
+ */
+ else if (twi->bytesRead < bytesToRead) {
+ uint8_t readAddress = twi->address | 0x01;
+ twi->interface->MASTER.ADDR = readAddress;
+ }
+
+ /* If transaction finished, send STOP condition and set RESULT OK. */
+ else {
+ twi->interface->MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
+ TWI_MasterTransactionFinished(twi, TWIM_RESULT_OK);
+ }
+}
+
+
+/*! \brief TWI master read interrupt handler.
+ *
+ * This is the master read interrupt handler that takes care of
+ * reading bytes from the TWI slave.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ */
+void TWI_MasterReadHandler(TWI_Master_t *twi)
+{
+ /* Fetch data if bytes to be read. */
+ if (twi->bytesRead < TWIM_READ_BUFFER_SIZE) {
+ uint8_t data = twi->interface->MASTER.DATA;
+ twi->readData[twi->bytesRead] = data;
+ twi->bytesRead++;
+ }
+
+ /* If buffer overflow, issue STOP and BUFFER_OVERFLOW condition. */
+ else {
+ twi->interface->MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
+ TWI_MasterTransactionFinished(twi, TWIM_RESULT_BUFFER_OVERFLOW);
+ }
+
+ /* Local variable used in if test to avoid compiler warning. */
+ uint8_t bytesToRead = twi->bytesToRead;
+
+ /* If more bytes to read, issue ACK and start a byte read. */
+ if (twi->bytesRead < bytesToRead) {
+ twi->interface->MASTER.CTRLC = TWI_MASTER_CMD_RECVTRANS_gc;
+ }
+
+ /* If transaction finished, issue NACK and STOP condition. */
+ else {
+ twi->interface->MASTER.CTRLC = TWI_MASTER_ACKACT_bm |
+ TWI_MASTER_CMD_STOP_gc;
+ TWI_MasterTransactionFinished(twi, TWIM_RESULT_OK);
+ }
+}
+
+
+/*! \brief TWI transaction finished handler.
+ *
+ * Prepares module for new transaction.
+ *
+ * \param twi The TWI_Master_t struct instance.
+ * \param result The result of the operation.
+ */
+void TWI_MasterTransactionFinished(TWI_Master_t *twi, uint8_t result)
+{
+ twi->result = result;
+ twi->status = TWIM_STATUS_READY;
+}
+
+
+
+
+
+
+
+
+
+
+
+#endif /* TWI_MASTER_DRIVER_H */
--
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