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Diffstat (limited to 'drivers/avr/TWIlib.c')
-rw-r--r--drivers/avr/TWIlib.c232
1 files changed, 0 insertions, 232 deletions
diff --git a/drivers/avr/TWIlib.c b/drivers/avr/TWIlib.c
deleted file mode 100644
index b39e3054a5..0000000000
--- a/drivers/avr/TWIlib.c
+++ /dev/null
@@ -1,232 +0,0 @@
-/*
- * TWIlib.c
- *
- * Created: 6/01/2014 10:41:33 PM
- * Author: Chris Herring
- * http://www.chrisherring.net/all/tutorial-interrupt-driven-twi-interface-for-avr-part1/
- */
-
-#include <avr/io.h>
-#include <avr/interrupt.h>
-#include "TWIlib.h"
-#include "util/delay.h"
-
-void TWIInit()
-{
- TWIInfo.mode = Ready;
- TWIInfo.errorCode = 0xFF;
- TWIInfo.repStart = 0;
- // Set pre-scalers (no pre-scaling)
- TWSR = 0;
- // Set bit rate
- TWBR = ((F_CPU / TWI_FREQ) - 16) / 2;
- // Enable TWI and interrupt
- TWCR = (1 << TWIE) | (1 << TWEN);
-}
-
-uint8_t isTWIReady()
-{
- if ( (TWIInfo.mode == Ready) | (TWIInfo.mode == RepeatedStartSent) )
- {
- return 1;
- }
- else
- {
- return 0;
- }
-}
-
-uint8_t TWITransmitData(void *const TXdata, uint8_t dataLen, uint8_t repStart)
-{
- if (dataLen <= TXMAXBUFLEN)
- {
- // Wait until ready
- while (!isTWIReady()) {_delay_us(1);}
- // Set repeated start mode
- TWIInfo.repStart = repStart;
- // Copy data into the transmit buffer
- uint8_t *data = (uint8_t *)TXdata;
- for (int i = 0; i < dataLen; i++)
- {
- TWITransmitBuffer[i] = data[i];
- }
- // Copy transmit info to global variables
- TXBuffLen = dataLen;
- TXBuffIndex = 0;
-
- // If a repeated start has been sent, then devices are already listening for an address
- // and another start does not need to be sent.
- if (TWIInfo.mode == RepeatedStartSent)
- {
- TWIInfo.mode = Initializing;
- TWDR = TWITransmitBuffer[TXBuffIndex++]; // Load data to transmit buffer
- TWISendTransmit(); // Send the data
- }
- else // Otherwise, just send the normal start signal to begin transmission.
- {
- TWIInfo.mode = Initializing;
- TWISendStart();
- }
-
- }
- else
- {
- return 1; // return an error if data length is longer than buffer
- }
- return 0;
-}
-
-uint8_t TWIReadData(uint8_t TWIaddr, uint8_t bytesToRead, uint8_t repStart)
-{
- // Check if number of bytes to read can fit in the RXbuffer
- if (bytesToRead < RXMAXBUFLEN)
- {
- // Reset buffer index and set RXBuffLen to the number of bytes to read
- RXBuffIndex = 0;
- RXBuffLen = bytesToRead;
- // Create the one value array for the address to be transmitted
- uint8_t TXdata[1];
- // Shift the address and AND a 1 into the read write bit (set to write mode)
- TXdata[0] = (TWIaddr << 1) | 0x01;
- // Use the TWITransmitData function to initialize the transfer and address the slave
- TWITransmitData(TXdata, 1, repStart);
- }
- else
- {
- return 0;
- }
- return 1;
-}
-
-ISR (TWI_vect)
-{
- switch (TWI_STATUS)
- {
- // ----\/ ---- MASTER TRANSMITTER OR WRITING ADDRESS ----\/ ---- //
- case TWI_MT_SLAW_ACK: // SLA+W transmitted and ACK received
- // Set mode to Master Transmitter
- TWIInfo.mode = MasterTransmitter;
- case TWI_START_SENT: // Start condition has been transmitted
- case TWI_MT_DATA_ACK: // Data byte has been transmitted, ACK received
- if (TXBuffIndex < TXBuffLen) // If there is more data to send
- {
- TWDR = TWITransmitBuffer[TXBuffIndex++]; // Load data to transmit buffer
- TWIInfo.errorCode = TWI_NO_RELEVANT_INFO;
- TWISendTransmit(); // Send the data
- }
- // This transmission is complete however do not release bus yet
- else if (TWIInfo.repStart)
- {
- TWIInfo.errorCode = 0xFF;
- TWISendStart();
- }
- // All transmissions are complete, exit
- else
- {
- TWIInfo.mode = Ready;
- TWIInfo.errorCode = 0xFF;
- TWISendStop();
- }
- break;
-
- // ----\/ ---- MASTER RECEIVER ----\/ ---- //
-
- case TWI_MR_SLAR_ACK: // SLA+R has been transmitted, ACK has been received
- // Switch to Master Receiver mode
- TWIInfo.mode = MasterReceiver;
- // If there is more than one byte to be read, receive data byte and return an ACK
- if (RXBuffIndex < RXBuffLen-1)
- {
- TWIInfo.errorCode = TWI_NO_RELEVANT_INFO;
- TWISendACK();
- }
- // Otherwise when a data byte (the only data byte) is received, return NACK
- else
- {
- TWIInfo.errorCode = TWI_NO_RELEVANT_INFO;
- TWISendNACK();
- }
- break;
-
- case TWI_MR_DATA_ACK: // Data has been received, ACK has been transmitted.
-
- /// -- HANDLE DATA BYTE --- ///
- TWIReceiveBuffer[RXBuffIndex++] = TWDR;
- // If there is more than one byte to be read, receive data byte and return an ACK
- if (RXBuffIndex < RXBuffLen-1)
- {
- TWIInfo.errorCode = TWI_NO_RELEVANT_INFO;
- TWISendACK();
- }
- // Otherwise when a data byte (the only data byte) is received, return NACK
- else
- {
- TWIInfo.errorCode = TWI_NO_RELEVANT_INFO;
- TWISendNACK();
- }
- break;
-
- case TWI_MR_DATA_NACK: // Data byte has been received, NACK has been transmitted. End of transmission.
-
- /// -- HANDLE DATA BYTE --- ///
- TWIReceiveBuffer[RXBuffIndex++] = TWDR;
- // This transmission is complete however do not release bus yet
- if (TWIInfo.repStart)
- {
- TWIInfo.errorCode = 0xFF;
- TWISendStart();
- }
- // All transmissions are complete, exit
- else
- {
- TWIInfo.mode = Ready;
- TWIInfo.errorCode = 0xFF;
- TWISendStop();
- }
- break;
-
- // ----\/ ---- MT and MR common ----\/ ---- //
-
- case TWI_MR_SLAR_NACK: // SLA+R transmitted, NACK received
- case TWI_MT_SLAW_NACK: // SLA+W transmitted, NACK received
- case TWI_MT_DATA_NACK: // Data byte has been transmitted, NACK received
- case TWI_LOST_ARBIT: // Arbitration has been lost
- // Return error and send stop and set mode to ready
- if (TWIInfo.repStart)
- {
- TWIInfo.errorCode = TWI_STATUS;
- TWISendStart();
- }
- // All transmissions are complete, exit
- else
- {
- TWIInfo.mode = Ready;
- TWIInfo.errorCode = TWI_STATUS;
- TWISendStop();
- }
- break;
- case TWI_REP_START_SENT: // Repeated start has been transmitted
- // Set the mode but DO NOT clear TWINT as the next data is not yet ready
- TWIInfo.mode = RepeatedStartSent;
- break;
-
- // ----\/ ---- SLAVE RECEIVER ----\/ ---- //
-
- // TODO IMPLEMENT SLAVE RECEIVER FUNCTIONALITY
-
- // ----\/ ---- SLAVE TRANSMITTER ----\/ ---- //
-
- // TODO IMPLEMENT SLAVE TRANSMITTER FUNCTIONALITY
-
- // ----\/ ---- MISCELLANEOUS STATES ----\/ ---- //
- case TWI_NO_RELEVANT_INFO: // It is not really possible to get into this ISR on this condition
- // Rather, it is there to be manually set between operations
- break;
- case TWI_ILLEGAL_START_STOP: // Illegal START/STOP, abort and return error
- TWIInfo.errorCode = TWI_ILLEGAL_START_STOP;
- TWIInfo.mode = Ready;
- TWISendStop();
- break;
- }
-
-}
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