Adding SAM specific libraries

This commit is contained in:
Thibaut VIARD 2011-06-21 00:03:22 +02:00
parent 9037be21e0
commit be2c9273c2
17 changed files with 1682 additions and 0 deletions

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/*
* Copyright (c) 2010 by Cristian Maglie <c.maglie@bug.st>
* SPI Master library for arduino.
*
* This file is free software; you can redistribute it and/or modify
* it under the terms of either the GNU General Public License version 2
* or the GNU Lesser General Public License version 2.1, both as
* published by the Free Software Foundation.
*/
#include "pins_arduino.h"
#include "SPI.h"
SPIClass SPI;
void SPIClass::begin() {
// Set direction register for SCK and MOSI pin.
// MISO pin automatically overrides to INPUT.
// When the SS pin is set as OUTPUT, it can be used as
// a general purpose output port (it doesn't influence
// SPI operations).
pinMode(SCK, OUTPUT);
pinMode(MOSI, OUTPUT);
pinMode(SS, OUTPUT);
digitalWrite(SCK, LOW);
digitalWrite(MOSI, LOW);
digitalWrite(SS, HIGH);
// Warning: if the SS pin ever becomes a LOW INPUT then SPI
// automatically switches to Slave, so the data direction of
// the SS pin MUST be kept as OUTPUT.
SPCR |= _BV(MSTR);
SPCR |= _BV(SPE);
}
void SPIClass::end() {
SPCR &= ~_BV(SPE);
}
void SPIClass::setBitOrder(uint8_t bitOrder)
{
if(bitOrder == LSBFIRST) {
SPCR |= _BV(DORD);
} else {
SPCR &= ~(_BV(DORD));
}
}
void SPIClass::setDataMode(uint8_t mode)
{
SPCR = (SPCR & ~SPI_MODE_MASK) | mode;
}
void SPIClass::setClockDivider(uint8_t rate)
{
SPCR = (SPCR & ~SPI_CLOCK_MASK) | (rate & SPI_CLOCK_MASK);
SPSR = (SPSR & ~SPI_2XCLOCK_MASK) | ((rate >> 2) & SPI_2XCLOCK_MASK);
}

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/*
* Copyright (c) 2010 by Cristian Maglie <c.maglie@bug.st>
* SPI Master library for arduino.
*
* This file is free software; you can redistribute it and/or modify
* it under the terms of either the GNU General Public License version 2
* or the GNU Lesser General Public License version 2.1, both as
* published by the Free Software Foundation.
*/
#ifndef _SPI_H_INCLUDED
#define _SPI_H_INCLUDED
#include <stdio.h>
#include <Arduino.h>
#include <avr/pgmspace.h>
#define SPI_CLOCK_DIV4 0x00
#define SPI_CLOCK_DIV16 0x01
#define SPI_CLOCK_DIV64 0x02
#define SPI_CLOCK_DIV128 0x03
#define SPI_CLOCK_DIV2 0x04
#define SPI_CLOCK_DIV8 0x05
#define SPI_CLOCK_DIV32 0x06
#define SPI_CLOCK_DIV64 0x07
#define SPI_MODE0 0x00
#define SPI_MODE1 0x04
#define SPI_MODE2 0x08
#define SPI_MODE3 0x0C
#define SPI_MODE_MASK 0x0C // CPOL = bit 3, CPHA = bit 2 on SPCR
#define SPI_CLOCK_MASK 0x03 // SPR1 = bit 1, SPR0 = bit 0 on SPCR
#define SPI_2XCLOCK_MASK 0x01 // SPI2X = bit 0 on SPSR
class SPIClass {
public:
inline static byte transfer(byte _data);
// SPI Configuration methods
inline static void attachInterrupt();
inline static void detachInterrupt(); // Default
static void begin(); // Default
static void end();
static void setBitOrder(uint8_t);
static void setDataMode(uint8_t);
static void setClockDivider(uint8_t);
};
extern SPIClass SPI;
byte SPIClass::transfer(byte _data) {
SPDR = _data;
while (!(SPSR & _BV(SPIF)))
;
return SPDR;
}
void SPIClass::attachInterrupt() {
SPCR |= _BV(SPIE);
}
void SPIClass::detachInterrupt() {
SPCR &= ~_BV(SPIE);
}
#endif

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/*
SCP1000 Barometric Pressure Sensor Display
Shows the output of a Barometric Pressure Sensor on a
Uses the SPI library. For details on the sensor, see:
http://www.sparkfun.com/commerce/product_info.php?products_id=8161
http://www.vti.fi/en/support/obsolete_products/pressure_sensors/
This sketch adapted from Nathan Seidle's SCP1000 example for PIC:
http://www.sparkfun.com/datasheets/Sensors/SCP1000-Testing.zip
Circuit:
SCP1000 sensor attached to pins 6, 7, 10 - 13:
DRDY: pin 6
CSB: pin 7
MOSI: pin 11
MISO: pin 12
SCK: pin 13
created 31 July 2010
modified 14 August 2010
by Tom Igoe
*/
// the sensor communicates using SPI, so include the library:
#include <SPI.h>
//Sensor's memory register addresses:
const int PRESSURE = 0x1F; //3 most significant bits of pressure
const int PRESSURE_LSB = 0x20; //16 least significant bits of pressure
const int TEMPERATURE = 0x21; //16 bit temperature reading
const byte READ = 0b11111100; // SCP1000's read command
const byte WRITE = 0b00000010; // SCP1000's write command
// pins used for the connection with the sensor
// the other you need are controlled by the SPI library):
const int dataReadyPin = 6;
const int chipSelectPin = 7;
void setup() {
Serial.begin(9600);
// start the SPI library:
SPI.begin();
// initalize the data ready and chip select pins:
pinMode(dataReadyPin, INPUT);
pinMode(chipSelectPin, OUTPUT);
//Configure SCP1000 for low noise configuration:
writeRegister(0x02, 0x2D);
writeRegister(0x01, 0x03);
writeRegister(0x03, 0x02);
// give the sensor time to set up:
delay(100);
}
void loop() {
//Select High Resolution Mode
writeRegister(0x03, 0x0A);
// don't do anything until the data ready pin is high:
if (digitalRead(dataReadyPin) == HIGH) {
//Read the temperature data
int tempData = readRegister(0x21, 2);
// convert the temperature to celsius and display it:
float realTemp = (float)tempData / 20.0;
Serial.print("Temp[C]=");
Serial.print(realTemp);
//Read the pressure data highest 3 bits:
byte pressure_data_high = readRegister(0x1F, 1);
pressure_data_high &= 0b00000111; //you only needs bits 2 to 0
//Read the pressure data lower 16 bits:
unsigned int pressure_data_low = readRegister(0x20, 2);
//combine the two parts into one 19-bit number:
long pressure = ((pressure_data_high << 16) | pressure_data_low)/4;
// display the temperature:
Serial.println("\tPressure [Pa]=" + String(pressure));
}
}
//Read from or write to register from the SCP1000:
unsigned int readRegister(byte thisRegister, int bytesToRead ) {
byte inByte = 0; // incoming byte from the SPI
unsigned int result = 0; // result to return
Serial.print(thisRegister, BIN);
Serial.print("\t");
// SCP1000 expects the register name in the upper 6 bits
// of the byte. So shift the bits left by two bits:
thisRegister = thisRegister << 2;
// now combine the address and the command into one byte
byte dataToSend = thisRegister & READ;
Serial.println(thisRegister, BIN);
// take the chip select low to select the device:
digitalWrite(chipSelectPin, LOW);
// send the device the register you want to read:
SPI.transfer(dataToSend);
// send a value of 0 to read the first byte returned:
result = SPI.transfer(0x00);
// decrement the number of bytes left to read:
bytesToRead--;
// if you still have another byte to read:
if (bytesToRead > 0) {
// shift the first byte left, then get the second byte:
result = result << 8;
inByte = SPI.transfer(0x00);
// combine the byte you just got with the previous one:
result = result | inByte;
// decrement the number of bytes left to read:
bytesToRead--;
}
// take the chip select high to de-select:
digitalWrite(chipSelectPin, HIGH);
// return the result:
return(result);
}
//Sends a write command to SCP1000
void writeRegister(byte thisRegister, byte thisValue) {
// SCP1000 expects the register address in the upper 6 bits
// of the byte. So shift the bits left by two bits:
thisRegister = thisRegister << 2;
// now combine the register address and the command into one byte:
byte dataToSend = thisRegister | WRITE;
// take the chip select low to select the device:
digitalWrite(chipSelectPin, LOW);
SPI.transfer(dataToSend); //Send register location
SPI.transfer(thisValue); //Send value to record into register
// take the chip select high to de-select:
digitalWrite(chipSelectPin, HIGH);
}

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/*
SCP1000 Barometric Pressure Sensor Display
Shows the output of a Barometric Pressure Sensor on a
Uses the SPI library. For details on the sensor, see:
http://www.sparkfun.com/commerce/product_info.php?products_id=8161
http://www.vti.fi/en/support/obsolete_products/pressure_sensors/
This sketch adapted from Nathan Seidle's SCP1000 example for PIC:
http://www.sparkfun.com/datasheets/Sensors/SCP1000-Testing.zip
Circuit:
SCP1000 sensor attached to pins 6, 7, 10 - 13:
DRDY: pin 6
CSB: pin 7
MOSI: pin 11
MISO: pin 12
SCK: pin 13
created 31 July 2010
modified 14 August 2010
by Tom Igoe
*/
// the sensor communicates using SPI, so include the library:
#include <SPI.h>
//Sensor's memory register addresses:
const int PRESSURE = 0x1F; //3 most significant bits of pressure
const int PRESSURE_LSB = 0x20; //16 least significant bits of pressure
const int TEMPERATURE = 0x21; //16 bit temperature reading
cont byte READ = 0b00000000; // SCP1000's read command
const byte WRITE = 0b00000010; // SCP1000's write command
// pins used for the connection with the sensor
// the other you need are controlled by the SPI library):
const int dataReadyPin = 6;
const int chipSelectPin = 7;
void setup() {
Serial.begin(9600);
// start the SPI library:
SPI.begin();
// initalize the data ready and chip select pins:
pinMode(dataReadyPin, INPUT);
pinMode(chipSelectPin, OUTPUT);
//Configure SCP1000 for low noise configuration:
writeRegister(0x02, 0x2D);
writeRegister(0x01, 0x03);
writeRegister(0x03, 0x02);
// give the sensor time to set up:
delay(100);
}
void loop() {
//Select High Resolution Mode
writeRegister(0x03, 0x0A);
// don't do anything until the data ready pin is high:
if (digitalRead(dataReadyPin) == HIGH) {
//Read the temperature data
int tempData = readRegister(0x21, 2);
// convert the temperature to celsius and display it:
float realTemp = (float)tempData / 20.0;
Serial.print("Temp[C]=");
Serial.print(realTemp);
//Read the pressure data highest 3 bits:
byte pressure_data_high = readRegister(0x1F, 1);
pressure_data_high &= 0b00000111; //you only needs bits 2 to 0
//Read the pressure data lower 16 bits:
unsigned int pressure_data_low = readRegister(0x20, 2);
//combine the two parts into one 19-bit number:
long pressure = ((pressure_data_high << 16) | pressure_data_low)/4;
// display the temperature:
Serial.println("\tPressure [Pa]=" + String(pressure));
}
}
//Read from or write to register from the SCP1000:
unsigned int readRegister(byte thisRegister, int bytesToRead ) {
byte inByte = 0; // incoming byte from the SPI
unsigned int result = 0; // result to return
// SCP1000 expects the register name in the upper 6 bits
// of the byte. So shift the bits left by two bits:
thisRegister = thisRegister << 2;
// now combine the address and the command into one byte
dataToSend = thisRegister & READ;
// take the chip select low to select the device:
digitalWrite(chipSelectPin, LOW);
// send the device the register you want to read:
SPI.transfer(dataToSend);
// send a value of 0 to read the first byte returned:
result = SPI.transfer(0x00);
// decrement the number of bytes left to read:
bytesToRead--;
// if you still have another byte to read:
if (bytesToRead > 0) {
// shift the first byte left, then get the second byte:
result = result << 8;
inByte = SPI.transfer(0x00);
// combine the byte you just got with the previous one:
result = result | inByte;
// decrement the number of bytes left to read:
bytesToRead--;
}
// take the chip select high to de-select:
digitalWrite(chipSelectPin, HIGH);
// return the result:
return(result);
}
//Sends a write command to SCP1000
void writeRegister(byte thisRegister, byte thisValue) {
// SCP1000 expects the register address in the upper 6 bits
// of the byte. So shift the bits left by two bits:
thisRegister = thisRegister << 2;
// now combine the register address and the command into one byte:
dataToSend = thisRegister | WRITE;
// take the chip select low to select the device:
digitalWrite(chipSelectPin, LOW);
SPI.transfer(dataToSend); //Send register location
SPI.transfer(thisValue); //Send value to record into register
// take the chip select high to de-select:
digitalWrite(chipSelectPin, HIGH);
}

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/*
Digital Pot Control
This example controls an Analog Devices AD5206 digital potentiometer.
The AD5206 has 6 potentiometer channels. Each channel's pins are labeled
A - connect this to voltage
W - this is the pot's wiper, which changes when you set it
B - connect this to ground.
The AD5206 is SPI-compatible,and to command it, you send two bytes,
one with the channel number (0 - 5) and one with the resistance value for the
channel (0 - 255).
The circuit:
* All A pins of AD5206 connected to +5V
* All B pins of AD5206 connected to ground
* An LED and a 220-ohm resisor in series connected from each W pin to ground
* CS - to digital pin 10 (SS pin)
* SDI - to digital pin 11 (MOSI pin)
* CLK - to digital pin 13 (SCK pin)
created 10 Aug 2010
by Tom Igoe
Thanks to Heather Dewey-Hagborg for the original tutorial, 2005
*/
// inslude the SPI library:
#include <SPI.h>
// set pin 10 as the slave select for the digital pot:
const int slaveSelectPin = 10;
void setup() {
// set the slaveSelectPin as an output:
pinMode (slaveSelectPin, OUTPUT);
// initialize SPI:
SPI.begin();
}
void loop() {
// go through the six channels of the digital pot:
for (int channel = 0; channel < 6; channel++) {
// change the resistance on this channel from min to max:
for (int level = 0; level < 255; level++) {
digitalPotWrite(channel, level);
delay(10);
}
// wait a second at the top:
delay(100);
// change the resistance on this channel from max to min:
for (int level = 0; level < 255; level++) {
digitalPotWrite(channel, 255 - level);
delay(10);
}
}
}
int digitalPotWrite(int address, int value) {
// take the SS pin low to select the chip:
digitalWrite(slaveSelectPin,LOW);
// send in the address and value via SPI:
SPI.transfer(address);
SPI.transfer(value);
// take the SS pin high to de-select the chip:
digitalWrite(slaveSelectPin,HIGH);
}

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#######################################
# Syntax Coloring Map SPI
#######################################
#######################################
# Datatypes (KEYWORD1)
#######################################
SPI KEYWORD1
#######################################
# Methods and Functions (KEYWORD2)
#######################################
begin KEYWORD2
end KEYWORD2
transfer KEYWORD2
setBitOrder KEYWORD2
setDataMode KEYWORD2
setClockDivider KEYWORD2
#######################################
# Constants (LITERAL1)
#######################################
SPI_CLOCK_DIV4 LITERAL1
SPI_CLOCK_DIV16 LITERAL1
SPI_CLOCK_DIV64 LITERAL1
SPI_CLOCK_DIV128 LITERAL1
SPI_CLOCK_DIV2 LITERAL1
SPI_CLOCK_DIV8 LITERAL1
SPI_CLOCK_DIV32 LITERAL1
SPI_CLOCK_DIV64 LITERAL1
SPI_MODE0 LITERAL1
SPI_MODE1 LITERAL1
SPI_MODE2 LITERAL1
SPI_MODE3 LITERAL1

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/*
TwoWire.cpp - TWI/I2C library for Wiring & Arduino
Copyright (c) 2006 Nicholas Zambetti. All right reserved.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
extern "C" {
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
#include "twi.h"
}
#include "Wire.h"
// Initialize Class Variables //////////////////////////////////////////////////
uint8_t TwoWire::rxBuffer[BUFFER_LENGTH];
uint8_t TwoWire::rxBufferIndex = 0;
uint8_t TwoWire::rxBufferLength = 0;
uint8_t TwoWire::txAddress = 0;
uint8_t TwoWire::txBuffer[BUFFER_LENGTH];
uint8_t TwoWire::txBufferIndex = 0;
uint8_t TwoWire::txBufferLength = 0;
uint8_t TwoWire::transmitting = 0;
void (*TwoWire::user_onRequest)(void);
void (*TwoWire::user_onReceive)(int);
// Constructors ////////////////////////////////////////////////////////////////
TwoWire::TwoWire()
{
}
// Public Methods //////////////////////////////////////////////////////////////
void TwoWire::begin(void)
{
rxBufferIndex = 0;
rxBufferLength = 0;
txBufferIndex = 0;
txBufferLength = 0;
twi_init();
}
void TwoWire::begin(uint8_t address)
{
twi_setAddress(address);
twi_attachSlaveTxEvent(onRequestService);
twi_attachSlaveRxEvent(onReceiveService);
begin();
}
void TwoWire::begin(int address)
{
begin((uint8_t)address);
}
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
uint8_t read = twi_readFrom(address, rxBuffer, quantity);
// set rx buffer iterator vars
rxBufferIndex = 0;
rxBufferLength = read;
return read;
}
uint8_t TwoWire::requestFrom(int address, int quantity)
{
return requestFrom((uint8_t)address, (uint8_t)quantity);
}
void TwoWire::beginTransmission(uint8_t address)
{
// indicate that we are transmitting
transmitting = 1;
// set address of targeted slave
txAddress = address;
// reset tx buffer iterator vars
txBufferIndex = 0;
txBufferLength = 0;
}
void TwoWire::beginTransmission(int address)
{
beginTransmission((uint8_t)address);
}
uint8_t TwoWire::endTransmission(void)
{
// transmit buffer (blocking)
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:
// slave tx event callback
// or after beginTransmission(address)
void TwoWire::write(uint8_t data)
{
if(transmitting){
// in master transmitter mode
// don't bother if buffer is full
if(txBufferLength >= BUFFER_LENGTH){
return;
}
// put byte in tx buffer
txBuffer[txBufferIndex] = data;
++txBufferIndex;
// update amount in buffer
txBufferLength = txBufferIndex;
}else{
// in slave send mode
// reply to master
twi_transmit(&data, 1);
}
}
// must be called in:
// slave tx event callback
// or after beginTransmission(address)
void TwoWire::write(const uint8_t *data, size_t quantity)
{
if(transmitting){
// in master transmitter mode
for(size_t i = 0; i < quantity; ++i){
write(data[i]);
}
}else{
// in slave send mode
// reply to master
twi_transmit(data, quantity);
}
}
// must be called in:
// slave tx event callback
// or after beginTransmission(address)
void TwoWire::write(const char *data)
{
write((uint8_t*)data, strlen(data));
}
// must be called in:
// slave rx event callback
// or after requestFrom(address, numBytes)
int TwoWire::available(void)
{
return rxBufferLength - rxBufferIndex;
}
// must be called in:
// slave rx event callback
// or after requestFrom(address, numBytes)
int TwoWire::read(void)
{
int value = -1;
// get each successive byte on each call
if(rxBufferIndex < rxBufferLength){
value = rxBuffer[rxBufferIndex];
++rxBufferIndex;
}
return value;
}
// must be called in:
// slave rx event callback
// or after requestFrom(address, numBytes)
int TwoWire::peek(void)
{
int value = -1;
if(rxBufferIndex < rxBufferLength){
value = rxBuffer[rxBufferIndex];
}
return value;
}
void TwoWire::flush(void)
{
// XXX: to be implemented.
}
// behind the scenes function that is called when data is received
void TwoWire::onReceiveService(uint8_t* inBytes, int numBytes)
{
// don't bother if user hasn't registered a callback
if(!user_onReceive){
return;
}
// don't bother if rx buffer is in use by a master requestFrom() op
// i know this drops data, but it allows for slight stupidity
// meaning, they may not have read all the master requestFrom() data yet
if(rxBufferIndex < rxBufferLength){
return;
}
// copy twi rx buffer into local read buffer
// this enables new reads to happen in parallel
for(uint8_t i = 0; i < numBytes; ++i){
rxBuffer[i] = inBytes[i];
}
// set rx iterator vars
rxBufferIndex = 0;
rxBufferLength = numBytes;
// alert user program
user_onReceive(numBytes);
}
// behind the scenes function that is called when data is requested
void TwoWire::onRequestService(void)
{
// don't bother if user hasn't registered a callback
if(!user_onRequest){
return;
}
// reset tx buffer iterator vars
// !!! this will kill any pending pre-master sendTo() activity
txBufferIndex = 0;
txBufferLength = 0;
// alert user program
user_onRequest();
}
// sets function called on slave write
void TwoWire::onReceive( void (*function)(int) )
{
user_onReceive = function;
}
// sets function called on slave read
void TwoWire::onRequest( void (*function)(void) )
{
user_onRequest = function;
}
// Preinstantiate Objects //////////////////////////////////////////////////////
TwoWire Wire = TwoWire();

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/*
TwoWire.h - TWI/I2C library for Arduino & Wiring
Copyright (c) 2006 Nicholas Zambetti. All right reserved.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef TwoWire_h
#define TwoWire_h
#include <inttypes.h>
#include "Stream.h"
#define BUFFER_LENGTH 32
class TwoWire : public Stream
{
private:
static uint8_t rxBuffer[];
static uint8_t rxBufferIndex;
static uint8_t rxBufferLength;
static uint8_t txAddress;
static uint8_t txBuffer[];
static uint8_t txBufferIndex;
static uint8_t txBufferLength;
static uint8_t transmitting;
static void (*user_onRequest)(void);
static void (*user_onReceive)(int);
static void onRequestService(void);
static void onReceiveService(uint8_t*, int);
public:
TwoWire();
void begin();
void begin(uint8_t);
void begin(int);
void beginTransmission(uint8_t);
void beginTransmission(int);
uint8_t endTransmission(void);
uint8_t requestFrom(uint8_t, uint8_t);
uint8_t requestFrom(int, int);
virtual void write(uint8_t);
virtual void write(const char *);
virtual void write(const uint8_t *, size_t);
virtual int available(void);
virtual int read(void);
virtual int peek(void);
virtual void flush(void);
void onReceive( void (*)(int) );
void onRequest( void (*)(void) );
};
extern TwoWire Wire;
#endif

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// I2C SRF10 or SRF08 Devantech Ultrasonic Ranger Finder
// by Nicholas Zambetti <http://www.zambetti.com>
// and James Tichenor <http://www.jamestichenor.net>
// Demonstrates use of the Wire library reading data from the
// Devantech Utrasonic Rangers SFR08 and SFR10
// Created 29 April 2006
// This example code is in the public domain.
#include <Wire.h>
void setup()
{
Wire.begin(); // join i2c bus (address optional for master)
Serial.begin(9600); // start serial communication at 9600bps
}
int reading = 0;
void loop()
{
// step 1: instruct sensor to read echoes
Wire.beginTransmission(112); // transmit to device #112 (0x70)
// the address specified in the datasheet is 224 (0xE0)
// but i2c adressing uses the high 7 bits so it's 112
Wire.write(byte(0x00)); // sets register pointer to the command register (0x00)
Wire.write(byte(0x50)); // command sensor to measure in "inches" (0x50)
// use 0x51 for centimeters
// use 0x52 for ping microseconds
Wire.endTransmission(); // stop transmitting
// step 2: wait for readings to happen
delay(70); // datasheet suggests at least 65 milliseconds
// step 3: instruct sensor to return a particular echo reading
Wire.beginTransmission(112); // transmit to device #112
Wire.write(byte(0x02)); // sets register pointer to echo #1 register (0x02)
Wire.endTransmission(); // stop transmitting
// step 4: request reading from sensor
Wire.requestFrom(112, 2); // request 2 bytes from slave device #112
// step 5: receive reading from sensor
if(2 <= Wire.available()) // if two bytes were received
{
reading = Wire.read(); // receive high byte (overwrites previous reading)
reading = reading << 8; // shift high byte to be high 8 bits
reading |= Wire.read(); // receive low byte as lower 8 bits
Serial.println(reading); // print the reading
}
delay(250); // wait a bit since people have to read the output :)
}
/*
// The following code changes the address of a Devantech Ultrasonic Range Finder (SRF10 or SRF08)
// usage: changeAddress(0x70, 0xE6);
void changeAddress(byte oldAddress, byte newAddress)
{
Wire.beginTransmission(oldAddress);
Wire.write(byte(0x00));
Wire.write(byte(0xA0));
Wire.endTransmission();
Wire.beginTransmission(oldAddress);
Wire.write(byte(0x00));
Wire.write(byte(0xAA));
Wire.endTransmission();
Wire.beginTransmission(oldAddress);
Wire.write(byte(0x00));
Wire.write(byte(0xA5));
Wire.endTransmission();
Wire.beginTransmission(oldAddress);
Wire.write(byte(0x00));
Wire.write(newAddress);
Wire.endTransmission();
}
*/

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// I2C Digital Potentiometer
// by Nicholas Zambetti <http://www.zambetti.com>
// and Shawn Bonkowski <http://people.interaction-ivrea.it/s.bonkowski/>
// Demonstrates use of the Wire library
// Controls AD5171 digital potentiometer via I2C/TWI
// Created 31 March 2006
// This example code is in the public domain.
// This example code is in the public domain.
#include <Wire.h>
void setup()
{
Wire.begin(); // join i2c bus (address optional for master)
}
byte val = 0;
void loop()
{
Wire.beginTransmission(44); // transmit to device #44 (0x2c)
// device address is specified in datasheet
Wire.write(byte(0x00)); // sends instruction byte
Wire.write(val); // sends potentiometer value byte
Wire.endTransmission(); // stop transmitting
val++; // increment value
if(val == 64) // if reached 64th position (max)
{
val = 0; // start over from lowest value
}
delay(500);
}

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// Wire Master Reader
// by Nicholas Zambetti <http://www.zambetti.com>
// Demonstrates use of the Wire library
// Reads data from an I2C/TWI slave device
// Refer to the "Wire Slave Sender" example for use with this
// Created 29 March 2006
// This example code is in the public domain.
#include <Wire.h>
void setup()
{
Wire.begin(); // join i2c bus (address optional for master)
Serial.begin(9600); // start serial for output
}
void loop()
{
Wire.requestFrom(2, 6); // request 6 bytes from slave device #2
while(Wire.available()) // slave may send less than requested
{
char c = Wire.read(); // receive a byte as character
Serial.print(c); // print the character
}
delay(500);
}

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// Wire Master Writer
// by Nicholas Zambetti <http://www.zambetti.com>
// Demonstrates use of the Wire library
// Writes data to an I2C/TWI slave device
// Refer to the "Wire Slave Receiver" example for use with this
// Created 29 March 2006
// This example code is in the public domain.
#include <Wire.h>
void setup()
{
Wire.begin(); // join i2c bus (address optional for master)
}
byte x = 0;
void loop()
{
Wire.beginTransmission(4); // transmit to device #4
Wire.write("x is "); // sends five bytes
Wire.write(x); // sends one byte
Wire.endTransmission(); // stop transmitting
x++;
delay(500);
}

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// Wire Slave Receiver
// by Nicholas Zambetti <http://www.zambetti.com>
// Demonstrates use of the Wire library
// Receives data as an I2C/TWI slave device
// Refer to the "Wire Master Writer" example for use with this
// Created 29 March 2006
// This example code is in the public domain.
#include <Wire.h>
void setup()
{
Wire.begin(4); // join i2c bus with address #4
Wire.onReceive(receiveEvent); // register event
Serial.begin(9600); // start serial for output
}
void loop()
{
delay(100);
}
// function that executes whenever data is received from master
// this function is registered as an event, see setup()
void receiveEvent(int howMany)
{
while(1 < Wire.available()) // loop through all but the last
{
char c = Wire.read(); // receive byte as a character
Serial.print(c); // print the character
}
int x = Wire.read(); // receive byte as an integer
Serial.println(x); // print the integer
}

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// Wire Slave Sender
// by Nicholas Zambetti <http://www.zambetti.com>
// Demonstrates use of the Wire library
// Sends data as an I2C/TWI slave device
// Refer to the "Wire Master Reader" example for use with this
// Created 29 March 2006
// This example code is in the public domain.
#include <Wire.h>
void setup()
{
Wire.begin(2); // join i2c bus with address #2
Wire.onRequest(requestEvent); // register event
}
void loop()
{
delay(100);
}
// function that executes whenever data is requested by master
// this function is registered as an event, see setup()
void requestEvent()
{
Wire.write("hello "); // respond with message of 6 bytes
// as expected by master
}

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#######################################
# Syntax Coloring Map For Wire
#######################################
#######################################
# Datatypes (KEYWORD1)
#######################################
#######################################
# Methods and Functions (KEYWORD2)
#######################################
begin KEYWORD2
beginTransmission KEYWORD2
endTransmission KEYWORD2
requestFrom KEYWORD2
send KEYWORD2
receive KEYWORD2
onReceive KEYWORD2
onRequest KEYWORD2
#######################################
# Instances (KEYWORD2)
#######################################
Wire KEYWORD2
#######################################
# Constants (LITERAL1)
#######################################

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/*
twi.c - TWI/I2C library for Wiring & Arduino
Copyright (c) 2006 Nicholas Zambetti. All right reserved.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <math.h>
#include <stdlib.h>
#include <inttypes.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <compat/twi.h>
#ifndef cbi
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#endif
#ifndef sbi
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
#endif
#include "twi.h"
static volatile uint8_t twi_state;
static uint8_t twi_slarw;
static void (*twi_onSlaveTransmit)(void);
static void (*twi_onSlaveReceive)(uint8_t*, int);
static uint8_t twi_masterBuffer[TWI_BUFFER_LENGTH];
static volatile uint8_t twi_masterBufferIndex;
static uint8_t twi_masterBufferLength;
static uint8_t twi_txBuffer[TWI_BUFFER_LENGTH];
static volatile uint8_t twi_txBufferIndex;
static volatile uint8_t twi_txBufferLength;
static uint8_t twi_rxBuffer[TWI_BUFFER_LENGTH];
static volatile uint8_t twi_rxBufferIndex;
static volatile uint8_t twi_error;
/*
* Function twi_init
* Desc readys twi pins and sets twi bitrate
* Input none
* Output none
*/
void twi_init(void)
{
// initialize state
twi_state = TWI_READY;
#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega8__) || defined(__AVR_ATmega328P__)
// activate internal pull-ups for twi
// as per note from atmega8 manual pg167
sbi(PORTC, 4);
sbi(PORTC, 5);
#else
// activate internal pull-ups for twi
// as per note from atmega128 manual pg204
sbi(PORTD, 0);
sbi(PORTD, 1);
#endif
// initialize twi prescaler and bit rate
cbi(TWSR, TWPS0);
cbi(TWSR, TWPS1);
TWBR = ((F_CPU / TWI_FREQ) - 16) / 2;
/* twi bit rate formula from atmega128 manual pg 204
SCL Frequency = CPU Clock Frequency / (16 + (2 * TWBR))
note: TWBR should be 10 or higher for master mode
It is 72 for a 16mhz Wiring board with 100kHz TWI */
// enable twi module, acks, and twi interrupt
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA);
}
/*
* Function twi_slaveInit
* Desc sets slave address and enables interrupt
* Input none
* Output none
*/
void twi_setAddress(uint8_t address)
{
// set twi slave address (skip over TWGCE bit)
TWAR = address << 1;
}
/*
* Function twi_readFrom
* Desc attempts to become twi bus master and read a
* series of bytes from a device on the bus
* Input address: 7bit i2c device address
* data: pointer to byte array
* length: number of bytes to read into array
* Output number of bytes read
*/
uint8_t twi_readFrom(uint8_t address, uint8_t* data, uint8_t length)
{
uint8_t i;
// ensure data will fit into buffer
if(TWI_BUFFER_LENGTH < length){
return 0;
}
// wait until twi is ready, become master receiver
while(TWI_READY != twi_state){
continue;
}
twi_state = TWI_MRX;
// reset error state (0xFF.. no error occured)
twi_error = 0xFF;
// initialize buffer iteration vars
twi_masterBufferIndex = 0;
twi_masterBufferLength = length-1; // This is not intuitive, read on...
// On receive, the previously configured ACK/NACK setting is transmitted in
// response to the received byte before the interrupt is signalled.
// Therefor we must actually set NACK when the _next_ to last byte is
// received, causing that NACK to be sent in response to receiving the last
// expected byte of data.
// build sla+w, slave device address + w bit
twi_slarw = TW_READ;
twi_slarw |= address << 1;
// send start condition
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT) | _BV(TWSTA);
// wait for read operation to complete
while(TWI_MRX == twi_state){
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 length;
}
/*
* Function twi_writeTo
* Desc attempts to become twi bus master and write a
* series of bytes to a device on the bus
* Input address: 7bit i2c device address
* data: pointer to byte array
* length: number of bytes in array
* wait: boolean indicating to wait for write or not
* 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)
{
uint8_t i;
// ensure data will fit into buffer
if(TWI_BUFFER_LENGTH < length){
return 1;
}
// wait until twi is ready, become master transmitter
while(TWI_READY != twi_state){
continue;
}
twi_state = TWI_MTX;
// reset error state (0xFF.. no error occured)
twi_error = 0xFF;
// initialize buffer iteration vars
twi_masterBufferIndex = 0;
twi_masterBufferLength = length;
// copy data to twi buffer
for(i = 0; i < length; ++i){
twi_masterBuffer[i] = data[i];
}
// build sla+w, slave device address + w bit
twi_slarw = TW_WRITE;
twi_slarw |= address << 1;
// send start condition
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT) | _BV(TWSTA);
// wait for write operation to complete
while(wait && (TWI_MTX == twi_state)){
continue;
}
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
}
/*
* Function twi_transmit
* Desc fills slave tx buffer with data
* must be called in slave tx event callback
* Input data: pointer to byte array
* length: number of bytes in array
* Output 1 length too long for buffer
* 2 not slave transmitter
* 0 ok
*/
uint8_t twi_transmit(const uint8_t* data, uint8_t length)
{
uint8_t i;
// ensure data will fit into buffer
if(TWI_BUFFER_LENGTH < length){
return 1;
}
// ensure we are currently a slave transmitter
if(TWI_STX != twi_state){
return 2;
}
// set length and copy data into tx buffer
twi_txBufferLength = length;
for(i = 0; i < length; ++i){
twi_txBuffer[i] = data[i];
}
return 0;
}
/*
* Function twi_attachSlaveRxEvent
* Desc sets function called before a slave read operation
* Input function: callback function to use
* Output none
*/
void twi_attachSlaveRxEvent( void (*function)(uint8_t*, int) )
{
twi_onSlaveReceive = function;
}
/*
* Function twi_attachSlaveTxEvent
* Desc sets function called before a slave write operation
* Input function: callback function to use
* Output none
*/
void twi_attachSlaveTxEvent( void (*function)(void) )
{
twi_onSlaveTransmit = function;
}
/*
* Function twi_reply
* Desc sends byte or readys receive line
* Input ack: byte indicating to ack or to nack
* Output none
*/
void twi_reply(uint8_t ack)
{
// transmit master read ready signal, with or without ack
if(ack){
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWINT) | _BV(TWEA);
}else{
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWINT);
}
}
/*
* Function twi_stop
* Desc relinquishes bus master status
* Input none
* Output none
*/
void twi_stop(void)
{
// send stop condition
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT) | _BV(TWSTO);
// wait for stop condition to be exectued on bus
// TWINT is not set after a stop condition!
while(TWCR & _BV(TWSTO)){
continue;
}
// update twi state
twi_state = TWI_READY;
}
/*
* Function twi_releaseBus
* Desc releases bus control
* Input none
* Output none
*/
void twi_releaseBus(void)
{
// release bus
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT);
// update twi state
twi_state = TWI_READY;
}
SIGNAL(TWI_vect)
{
switch(TW_STATUS){
// All Master
case TW_START: // sent start condition
case TW_REP_START: // sent repeated start condition
// copy device address and r/w bit to output register and ack
TWDR = twi_slarw;
twi_reply(1);
break;
// Master Transmitter
case TW_MT_SLA_ACK: // slave receiver acked address
case TW_MT_DATA_ACK: // slave receiver acked data
// if there is data to send, send it, otherwise stop
if(twi_masterBufferIndex < twi_masterBufferLength){
// copy data to output register and ack
TWDR = twi_masterBuffer[twi_masterBufferIndex++];
twi_reply(1);
}else{
twi_stop();
}
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;
// Master Receiver
case TW_MR_DATA_ACK: // data received, ack sent
// put byte into buffer
twi_masterBuffer[twi_masterBufferIndex++] = TWDR;
case TW_MR_SLA_ACK: // address sent, ack received
// ack if more bytes are expected, otherwise nack
if(twi_masterBufferIndex < twi_masterBufferLength){
twi_reply(1);
}else{
twi_reply(0);
}
break;
case TW_MR_DATA_NACK: // data received, nack sent
// put final byte into buffer
twi_masterBuffer[twi_masterBufferIndex++] = TWDR;
case TW_MR_SLA_NACK: // address sent, nack received
twi_stop();
break;
// TW_MR_ARB_LOST handled by TW_MT_ARB_LOST case
// Slave Receiver
case TW_SR_SLA_ACK: // addressed, returned ack
case TW_SR_GCALL_ACK: // addressed generally, returned ack
case TW_SR_ARB_LOST_SLA_ACK: // lost arbitration, returned ack
case TW_SR_ARB_LOST_GCALL_ACK: // lost arbitration, returned ack
// enter slave receiver mode
twi_state = TWI_SRX;
// indicate that rx buffer can be overwritten and ack
twi_rxBufferIndex = 0;
twi_reply(1);
break;
case TW_SR_DATA_ACK: // data received, returned ack
case TW_SR_GCALL_DATA_ACK: // data received generally, returned ack
// if there is still room in the rx buffer
if(twi_rxBufferIndex < TWI_BUFFER_LENGTH){
// put byte in buffer and ack
twi_rxBuffer[twi_rxBufferIndex++] = TWDR;
twi_reply(1);
}else{
// otherwise nack
twi_reply(0);
}
break;
case TW_SR_STOP: // stop or repeated start condition received
// put a null char after data if there's room
if(twi_rxBufferIndex < TWI_BUFFER_LENGTH){
twi_rxBuffer[twi_rxBufferIndex] = '\0';
}
// sends ack and stops interface for clock stretching
twi_stop();
// callback to user defined callback
twi_onSlaveReceive(twi_rxBuffer, twi_rxBufferIndex);
// since we submit rx buffer to "wire" library, we can reset it
twi_rxBufferIndex = 0;
// ack future responses and leave slave receiver state
twi_releaseBus();
break;
case TW_SR_DATA_NACK: // data received, returned nack
case TW_SR_GCALL_DATA_NACK: // data received generally, returned nack
// nack back at master
twi_reply(0);
break;
// Slave Transmitter
case TW_ST_SLA_ACK: // addressed, returned ack
case TW_ST_ARB_LOST_SLA_ACK: // arbitration lost, returned ack
// enter slave transmitter mode
twi_state = TWI_STX;
// ready the tx buffer index for iteration
twi_txBufferIndex = 0;
// set tx buffer length to be zero, to verify if user changes it
twi_txBufferLength = 0;
// request for txBuffer to be filled and length to be set
// note: user must call twi_transmit(bytes, length) to do this
twi_onSlaveTransmit();
// if they didn't change buffer & length, initialize it
if(0 == twi_txBufferLength){
twi_txBufferLength = 1;
twi_txBuffer[0] = 0x00;
}
// transmit first byte from buffer, fall
case TW_ST_DATA_ACK: // byte sent, ack returned
// copy data to output register
TWDR = twi_txBuffer[twi_txBufferIndex++];
// if there is more to send, ack, otherwise nack
if(twi_txBufferIndex < twi_txBufferLength){
twi_reply(1);
}else{
twi_reply(0);
}
break;
case TW_ST_DATA_NACK: // received nack, we are done
case TW_ST_LAST_DATA: // received ack, but we are done already!
// ack future responses
twi_reply(1);
// leave slave receiver state
twi_state = TWI_READY;
break;
// All
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;
}
}

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/*
twi.h - TWI/I2C library for Wiring & Arduino
Copyright (c) 2006 Nicholas Zambetti. All right reserved.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef twi_h
#define twi_h
#include <inttypes.h>
//#define ATMEGA8
#ifndef TWI_FREQ
#define TWI_FREQ 100000L
#endif
#ifndef TWI_BUFFER_LENGTH
#define TWI_BUFFER_LENGTH 32
#endif
#define TWI_READY 0
#define TWI_MRX 1
#define TWI_MTX 2
#define TWI_SRX 3
#define TWI_STX 4
void twi_init(void);
void twi_setAddress(uint8_t);
uint8_t twi_readFrom(uint8_t, uint8_t*, uint8_t);
uint8_t twi_writeTo(uint8_t, uint8_t*, uint8_t, uint8_t);
uint8_t twi_transmit(const uint8_t*, uint8_t);
void twi_attachSlaveRxEvent( void (*)(uint8_t*, int) );
void twi_attachSlaveTxEvent( void (*)(void) );
void twi_reply(uint8_t);
void twi_stop(void);
void twi_releaseBus(void);
#endif