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ArduinoCore-avr
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Wire library patch to provide better error handling.

This commit is contained in:
David A. Mellis 2008-06-21 23:16:27 +00:00
parent 75d1f5053c
commit 79904311bb
5 changed files with 51 additions and 22 deletions
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2
cores/arduino/Print.cpp
View File

@ -30,7 +30,7 @@
void Print::print(uint8_t b)
{
write(b);
this->write(b);
}
void Print::print(char c)

17
libraries/Wire/Wire.cpp
View File

@ -77,22 +77,24 @@ void TwoWire::begin(int address)
begin((uint8_t)address);
}
void TwoWire::requestFrom(uint8_t address, uint8_t quantity)
uint8_t TwoWire::requestFrom(uint8_t address, uint8_t quantity)
{
// clamp to buffer length
if(quantity > BUFFER_LENGTH){
quantity = BUFFER_LENGTH;
}
// perform blocking read into buffer
twi_readFrom(address, rxBuffer, quantity);
uint8_t read = twi_readFrom(address, rxBuffer, quantity);
// set rx buffer iterator vars
rxBufferIndex = 0;
rxBufferLength = quantity;
rxBufferLength = read;
return read;
}
void TwoWire::requestFrom(int address, int quantity)
uint8_t TwoWire::requestFrom(int address, int quantity)
{
requestFrom((uint8_t)address, (uint8_t)quantity);
return requestFrom((uint8_t)address, (uint8_t)quantity);
}
void TwoWire::beginTransmission(uint8_t address)
@ -111,15 +113,16 @@ void TwoWire::beginTransmission(int address)
beginTransmission((uint8_t)address);
}
void TwoWire::endTransmission(void)
uint8_t TwoWire::endTransmission(void)
{
// transmit buffer (blocking)
twi_writeTo(txAddress, txBuffer, txBufferLength, 1);
int8_t ret = twi_writeTo(txAddress, txBuffer, txBufferLength, 1);
// reset tx buffer iterator vars
txBufferIndex = 0;
txBufferLength = 0;
// indicate that we are done transmitting
transmitting = 0;
return ret;
}
// must be called in:

6
libraries/Wire/Wire.h
View File

@ -48,9 +48,9 @@ class TwoWire
void begin(int);
void beginTransmission(uint8_t);
void beginTransmission(int);
void endTransmission(void);
void requestFrom(uint8_t, uint8_t);
void requestFrom(int, int);
uint8_t endTransmission(void);
uint8_t requestFrom(uint8_t, uint8_t);
uint8_t requestFrom(int, int);
void send(uint8_t);
void send(uint8_t*, uint8_t);
void send(int);

36
libraries/Wire/utility/twi.c
View File

@ -51,6 +51,8 @@ static volatile uint8_t twi_txBufferLength;
static uint8_t* twi_rxBuffer;
static volatile uint8_t twi_rxBufferIndex;
static volatile uint8_t twi_error;
/*
* Function twi_init
* Desc readys twi pins and sets twi bitrate
@ -112,7 +114,7 @@ void twi_setAddress(uint8_t address)
* Input address: 7bit i2c device address
* data: pointer to byte array
* length: number of bytes to read into array
* Output byte: 0 ok, 1 length too long for buffer
* Output number of bytes read
*/
uint8_t twi_readFrom(uint8_t address, uint8_t* data, uint8_t length)
{
@ -120,7 +122,7 @@ uint8_t twi_readFrom(uint8_t address, uint8_t* data, uint8_t length)
// ensure data will fit into buffer
if(TWI_BUFFER_LENGTH < length){
return 1;
return 0;
}
// wait until twi is ready, become master receiver
@ -128,6 +130,8 @@ uint8_t twi_readFrom(uint8_t address, uint8_t* data, uint8_t length)
continue;
}
twi_state = TWI_MRX;
// reset error state (0xFF.. no error occured)
twi_error = 0xFF;
// initialize buffer iteration vars
twi_masterBufferIndex = 0;
@ -145,12 +149,15 @@ uint8_t twi_readFrom(uint8_t address, uint8_t* data, uint8_t length)
continue;
}
if (twi_masterBufferIndex < length)
length = twi_masterBufferIndex;
// copy twi buffer to data
for(i = 0; i < length; ++i){
data[i] = twi_masterBuffer[i];
}
return 0;
return length;
}
/*
@ -161,7 +168,11 @@ uint8_t twi_readFrom(uint8_t address, uint8_t* data, uint8_t length)
* data: pointer to byte array
* length: number of bytes in array
* wait: boolean indicating to wait for write or not
* Output byte: 0 ok, 1 length too long for buffer
* Output 0 .. success
* 1 .. length to long for buffer
* 2 .. address send, NACK received
* 3 .. data send, NACK received
* 4 .. other twi error (lost bus arbitration, bus error, ..)
*/
uint8_t twi_writeTo(uint8_t address, uint8_t* data, uint8_t length, uint8_t wait)
{
@ -177,6 +188,8 @@ uint8_t twi_writeTo(uint8_t address, uint8_t* data, uint8_t length, uint8_t wait
continue;
}
twi_state = TWI_MTX;
// reset error state (0xFF.. no error occured)
twi_error = 0xFF;
// initialize buffer iteration vars
twi_masterBufferIndex = 0;
@ -199,7 +212,14 @@ uint8_t twi_writeTo(uint8_t address, uint8_t* data, uint8_t length, uint8_t wait
continue;
}
return 0;
if (twi_error == 0xFF)
return 0; // success
else if (twi_error == TW_MT_SLA_NACK)
return 2; // error: address send, nack received
else if (twi_error == TW_MT_DATA_NACK)
return 3; // error: data send, nack received
else
return 4; // other twi error
}
/*
@ -333,10 +353,15 @@ SIGNAL(SIG_2WIRE_SERIAL)
}
break;
case TW_MT_SLA_NACK: // address sent, nack received
twi_error = TW_MT_SLA_NACK;
twi_stop();
break;
case TW_MT_DATA_NACK: // data sent, nack received
twi_error = TW_MT_DATA_NACK;
twi_stop();
break;
case TW_MT_ARB_LOST: // lost bus arbitration
twi_error = TW_MT_ARB_LOST;
twi_releaseBus();
break;
@ -441,6 +466,7 @@ SIGNAL(SIG_2WIRE_SERIAL)
case TW_NO_INFO: // no state information
break;
case TW_BUS_ERROR: // bus error, illegal stop/start
twi_error = TW_BUS_ERROR;
twi_stop();
break;
}

12
libraries/Wire/utility/twi.h
View File

@ -17,18 +17,18 @@
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef twi_h
#define twi_h
#ifndef twi_h
#define twi_h
#include <inttypes.h>
//#define ATMEGA8
#ifndef CPU_FREQ
#ifndef CPU_FREQ
#define CPU_FREQ 16000000L
#endif
#ifndef TWI_FREQ
#ifndef TWI_FREQ
#define TWI_FREQ 100000L
#endif
@ -51,7 +51,7 @@
void twi_attachSlaveTxEvent( void (*)(void) );
void twi_reply(uint8_t);
void twi_stop(void);
void twi_releaseBus(void);
void twi_releaseBus(void);
#endif