Revision 2:8670e78c4b63, committed 2012-04-01

Comitter:

p3p

Date:

Sun Apr 01 22:52:47 2012 +0000

Parent:

1:6966eacc5914

Commit message:

Added the option to change the frequency (delay between GPIO toggles so blocking)

Changed in this revision

diff -r 6966eacc5914 -r 8670e78c4b63 SoftwareI2C.cpp
--- a/SoftwareI2C.cpp	Sun Apr 01 19:27:03 2012 +0000
+++ b/SoftwareI2C.cpp	Sun Apr 01 22:52:47 2012 +0000
@@ -1,211 +1,212 @@
-/* 
- * mbed Library to use a software master i2c interface on any GPIO pins
- * Copyright (c) 2012 Christopher Pepper
- * Released under the MIT License: http://mbed.org/license/mit
- */
-
-#include "SoftwareI2C.h"
-
-/**
- * @brief Initializes interface
- * @param sda GPIO pin to use as I2C SDA
- * @param scl GPIO pin to use as I2C SCL
- */
-
-SoftwareI2C::SoftwareI2C(PinName sda, PinName scl) : _sda(sda) , _scl(scl) {
-    _scl.output();
-    _scl.mode(OpenDrain);
-    _sda.output();
-    _sda.mode(OpenDrain);
-
-    _device_address = 0;
-
-    initialise();
-}
-
-SoftwareI2C::~SoftwareI2C() {
-
-}
-
-/**
- * @brief Read 1 or more bytes from the I2C slave
- * @param device_address The address of the device to read from
- * @param data An allocated array to read the data into
- * @param data_bytes Number of bytes to read (must be equal to or less then the allocated memory in data)
- */
-void SoftwareI2C::read(uint8_t device_address, uint8_t* data, uint8_t data_bytes) {
-    if (data == 0 || data_bytes == 0) return;
-
-    device_address = device_address | 0x01;
-    start();
-    putByte(device_address);
-    getAck();
-    for (int x = 0; x < data_bytes; ++x) {
-        data[x] = getByte();
-        if ( x < (data_bytes -1)) { //ack all but the final byte
-            giveAck();
-        }
-    }
-    stop();
-}
-
-/**
- * @brief Write 1 or more bytes to the I2C slave
- * @param device_address The address of the device to write to
- * @param data An array to write the data from
- * @param data_bytes Number of bytes to write from array
- */
-void SoftwareI2C::write(uint8_t device_address, uint8_t* data,  uint8_t data_bytes) {
-    if (data == 0 || data_bytes == 0) return;
-
-    device_address = device_address & 0xFE;
-    start();
-    putByte(device_address);
-    getAck();
-    for ( int x = 0; x < data_bytes; ++x ) {
-        putByte(data[x]);
-        getAck();
-    }
-    stop();
-}
-
-/**
- * @brief Write 1 byte to the I2C slave
- * @param device_address The address of the device to write to
- * @param byte The data to write
- */
-void SoftwareI2C::write(uint8_t device_address, uint8_t byte) {
-    device_address = device_address & 0xFE;
-    start();
-    putByte(device_address);
-    getAck();
-    putByte(byte);
-    getAck();
-    stop();
-}
-
-/**
- * @brief Read 1 or more bytes from the I2C slave at the specified memory address
- * @param device_address The address of the device to read from
- * @param start_address The memory address to read from
- * @param data The allocated array to read into
- * @param data_bytes The number of bytes to read
- */
-void SoftwareI2C::randomRead(uint8_t device_address, uint8_t start_address, uint8_t* data, uint8_t data_bytes) {
-    if (data == 0 || data_bytes == 0) return;
-
-    device_address = device_address & 0xFE;
-    start();
-    putByte(device_address);
-    if (!getAck()) {
-        return;
-    }
-    putByte(start_address);
-    if (!getAck()) {
-        return;
-    }
-
-    device_address=device_address | 0x01;
-    start();
-    putByte(device_address);
-    if (!getAck()) {
-        return;
-    }
-    for ( int x = 0; x < data_bytes; ++x) {
-        data[x] = getByte();
-        if (x != (data_bytes - 1)) giveAck();
-    }
-    stop();
-}
-
-/**
- * @brief Write 1 byte to the I2C slave at the specified memory address
- * @param device_address The address of the device to write to
- * @param start_address The memory address to write to
- * @param byte The data to write
- */
-void SoftwareI2C::randomWrite(uint8_t device_address, uint8_t start_address, uint8_t byte) {
-    device_address = device_address & 0xFE;
-    start();
-    putByte(device_address);
-    getAck();
-    putByte(start_address);
-    getAck();
-    putByte(byte);
-    getAck();
-    stop();
-}
-
-/**
- * @brief Write 1 or more bytes to the I2C slave at the specified memory address
- * @param device_address The address of the device to write to
- * @param start_address The memory address to write to
- * @param data The data to write
- * @param data_bytes The number of bytes to write
- */
-void SoftwareI2C::randomWrite(uint8_t device_address, uint8_t start_address, uint8_t* data, uint8_t data_bytes) {
-    if (data == 0 || data_bytes == 0) return;
-
-    device_address = device_address & 0xFE;
-    start();
-    putByte(device_address);
-    getAck();
-    putByte(start_address);
-    getAck();
-    for ( int x = 0; x <= data_bytes; ++x ) {
-        putByte(data[x]);
-        getAck();
-    }
-    stop();
-}
-
-/**
- * @brief Read 2 bytes from the I2C slave at the specified memory address and return them as an 16bit unsigned integer
- * @param device_address The address of the device to read from
- * @param start_address The memory address to read from
- * @return MSB 16bit unsigned integer
- */
-uint16_t SoftwareI2C::read16(uint8_t device_address, uint8_t start_address) {
-    uint8_t short_array[2] = {0, 0};
-    randomRead(device_address, start_address, short_array, 2 );
-    uint16_t value = 0;
-    value = short_array[0] << 8;
-    value |= short_array[1];
-
-    return value;
-}
-
-/**
- * @brief Read 3 bytes from the I2C slave at the specified memory address and return them as an 32bit unsigned integer
- * @param device_address The address of the device to read from
- * @param start_address The memory address to read from
- * @return MSB 32bit unsigned integer 
- */
-uint32_t SoftwareI2C::read24(uint8_t device_address, uint8_t start_address) {
-    uint8_t value_array[4] = {0, 0, 0};
-    randomRead(device_address, start_address, value_array, 3 );
-    uint32_t value = 0;
-    value = value_array[0] << 16;
-    value |= value_array[1] << 8;
-    value |= value_array[2];
-
-    return value;
-}
-
-/**
- * @brief Read 4 bytes from the I2C slave at the specified memory address and return them as an 32bit unsigned integer
- * @param device_address The address of the device to read from
- * @param start_address The memory address to read from
- * @return MSB 32bit unsigned integer
- */
-uint32_t SoftwareI2C::read32(uint8_t device_address, uint8_t start_address) {
-    uint8_t value_array[4] = {0, 0, 0, 0};
-    randomRead(device_address, start_address, value_array, 4 );
-    uint32_t value = 0;
-    value = value_array[0] << 24;
-    value |= value_array[1] << 16;
-    value |= value_array[2] << 8;
-    value |= value_array[3];
-
-    return value;
+/* 
+ * mbed Library to use a software master i2c interface on any GPIO pins
+ * Copyright (c) 2012 Christopher Pepper
+ * Released under the MIT License: http://mbed.org/license/mit
+ */
+
+#include "SoftwareI2C.h"
+
+/**
+ * @brief Initializes interface
+ * @param sda GPIO pin to use as I2C SDA
+ * @param scl GPIO pin to use as I2C SCL
+ */
+
+SoftwareI2C::SoftwareI2C(PinName sda, PinName scl) : _sda(sda) , _scl(scl) {
+    _scl.output();
+    _scl.mode(OpenDrain);
+    _sda.output();
+    _sda.mode(OpenDrain);
+
+    _device_address = 0;
+    _frequency_delay = 1;
+
+    initialise();
+}
+
+SoftwareI2C::~SoftwareI2C() {
+
+}
+
+/**
+ * @brief Read 1 or more bytes from the I2C slave
+ * @param device_address The address of the device to read from
+ * @param data An allocated array to read the data into
+ * @param data_bytes Number of bytes to read (must be equal to or less then the allocated memory in data)
+ */
+void SoftwareI2C::read(uint8_t device_address, uint8_t* data, uint8_t data_bytes) {
+    if (data == 0 || data_bytes == 0) return;
+
+    device_address = device_address | 0x01;
+    start();
+    putByte(device_address);
+    getAck();
+    for (int x = 0; x < data_bytes; ++x) {
+        data[x] = getByte();
+        if ( x < (data_bytes -1)) { //ack all but the final byte
+            giveAck();
+        }
+    }
+    stop();
+}
+
+/**
+ * @brief Write 1 or more bytes to the I2C slave
+ * @param device_address The address of the device to write to
+ * @param data An array to write the data from
+ * @param data_bytes Number of bytes to write from array
+ */
+void SoftwareI2C::write(uint8_t device_address, uint8_t* data,  uint8_t data_bytes) {
+    if (data == 0 || data_bytes == 0) return;
+
+    device_address = device_address & 0xFE;
+    start();
+    putByte(device_address);
+    getAck();
+    for ( int x = 0; x < data_bytes; ++x ) {
+        putByte(data[x]);
+        getAck();
+    }
+    stop();
+}
+
+/**
+ * @brief Write 1 byte to the I2C slave
+ * @param device_address The address of the device to write to
+ * @param byte The data to write
+ */
+void SoftwareI2C::write(uint8_t device_address, uint8_t byte) {
+    device_address = device_address & 0xFE;
+    start();
+    putByte(device_address);
+    getAck();
+    putByte(byte);
+    getAck();
+    stop();
+}
+
+/**
+ * @brief Read 1 or more bytes from the I2C slave at the specified memory address
+ * @param device_address The address of the device to read from
+ * @param start_address The memory address to read from
+ * @param data The allocated array to read into
+ * @param data_bytes The number of bytes to read
+ */
+void SoftwareI2C::randomRead(uint8_t device_address, uint8_t start_address, uint8_t* data, uint8_t data_bytes) {
+    if (data == 0 || data_bytes == 0) return;
+
+    device_address = device_address & 0xFE;
+    start();
+    putByte(device_address);
+    if (!getAck()) {
+        return;
+    }
+    putByte(start_address);
+    if (!getAck()) {
+        return;
+    }
+
+    device_address=device_address | 0x01;
+    start();
+    putByte(device_address);
+    if (!getAck()) {
+        return;
+    }
+    for ( int x = 0; x < data_bytes; ++x) {
+        data[x] = getByte();
+        if (x != (data_bytes - 1)) giveAck();
+    }
+    stop();
+}
+
+/**
+ * @brief Write 1 byte to the I2C slave at the specified memory address
+ * @param device_address The address of the device to write to
+ * @param start_address The memory address to write to
+ * @param byte The data to write
+ */
+void SoftwareI2C::randomWrite(uint8_t device_address, uint8_t start_address, uint8_t byte) {
+    device_address = device_address & 0xFE;
+    start();
+    putByte(device_address);
+    getAck();
+    putByte(start_address);
+    getAck();
+    putByte(byte);
+    getAck();
+    stop();
+}
+
+/**
+ * @brief Write 1 or more bytes to the I2C slave at the specified memory address
+ * @param device_address The address of the device to write to
+ * @param start_address The memory address to write to
+ * @param data The data to write
+ * @param data_bytes The number of bytes to write
+ */
+void SoftwareI2C::randomWrite(uint8_t device_address, uint8_t start_address, uint8_t* data, uint8_t data_bytes) {
+    if (data == 0 || data_bytes == 0) return;
+
+    device_address = device_address & 0xFE;
+    start();
+    putByte(device_address);
+    getAck();
+    putByte(start_address);
+    getAck();
+    for ( int x = 0; x <= data_bytes; ++x ) {
+        putByte(data[x]);
+        getAck();
+    }
+    stop();
+}
+
+/**
+ * @brief Read 2 bytes from the I2C slave at the specified memory address and return them as an 16bit unsigned integer
+ * @param device_address The address of the device to read from
+ * @param start_address The memory address to read from
+ * @return MSB 16bit unsigned integer
+ */
+uint16_t SoftwareI2C::read16(uint8_t device_address, uint8_t start_address) {
+    uint8_t short_array[2] = {0, 0};
+    randomRead(device_address, start_address, short_array, 2 );
+    uint16_t value = 0;
+    value = short_array[0] << 8;
+    value |= short_array[1];
+
+    return value;
+}
+
+/**
+ * @brief Read 3 bytes from the I2C slave at the specified memory address and return them as an 32bit unsigned integer
+ * @param device_address The address of the device to read from
+ * @param start_address The memory address to read from
+ * @return MSB 32bit unsigned integer 
+ */
+uint32_t SoftwareI2C::read24(uint8_t device_address, uint8_t start_address) {
+    uint8_t value_array[4] = {0, 0, 0};
+    randomRead(device_address, start_address, value_array, 3 );
+    uint32_t value = 0;
+    value = value_array[0] << 16;
+    value |= value_array[1] << 8;
+    value |= value_array[2];
+
+    return value;
+}
+
+/**
+ * @brief Read 4 bytes from the I2C slave at the specified memory address and return them as an 32bit unsigned integer
+ * @param device_address The address of the device to read from
+ * @param start_address The memory address to read from
+ * @return MSB 32bit unsigned integer
+ */
+uint32_t SoftwareI2C::read32(uint8_t device_address, uint8_t start_address) {
+    uint8_t value_array[4] = {0, 0, 0, 0};
+    randomRead(device_address, start_address, value_array, 4 );
+    uint32_t value = 0;
+    value = value_array[0] << 24;
+    value |= value_array[1] << 16;
+    value |= value_array[2] << 8;
+    value |= value_array[3];
+
+    return value;
 }
\ No newline at end of file

diff -r 6966eacc5914 -r 8670e78c4b63 SoftwareI2C.h
--- a/SoftwareI2C.h	Sun Apr 01 19:27:03 2012 +0000
+++ b/SoftwareI2C.h	Sun Apr 01 22:52:47 2012 +0000
@@ -33,6 +33,10 @@
     void setDeviceAddress(uint8_t address){
         _device_address = address;
     }
+    
+    void setFrequency(uint32_t frequency){
+        _frequency_delay = 1000000 / frequency;
+    }
 
     inline void initialise() {
         _scl.output();
@@ -40,7 +44,7 @@
         
         _sda = 1;
         _scl = 0;
-        wait_us(10);
+        wait_us(_frequency_delay);
 
         for ( int n = 0; n <= 3; ++n ) {
             stop();
@@ -50,33 +54,33 @@
 private:
     inline void start() {
         _sda.output();
-        wait_us(1);
+        wait_us(_frequency_delay);
         _scl = 1;
         _sda = 1;
-        wait_us(1);
+        wait_us(_frequency_delay);
         _sda = 0;
-        wait_us(1);
+        wait_us(_frequency_delay);
         _scl = 0;
-        wait_us(1);
+        wait_us(_frequency_delay);
     }
 
     inline void stop() {
         _sda.output();
-        wait_us(1);
+        wait_us(_frequency_delay);
         _sda = 0;
-        wait_us(1);
+        wait_us(_frequency_delay);
         _scl = 1;
-        wait_us(1);
+        wait_us(_frequency_delay);
         _sda = 1;
     }
 
     inline void putByte(uint8_t byte) {
         _sda.output();
         for ( int n = 8; n > 0; --n) {
-            wait_us(1);
+            wait_us(_frequency_delay);
             _sda = byte & (1 << (n-1));
             _scl = 1;
-            wait_us(1);
+            wait_us(_frequency_delay);
             _scl = 0;
         }
         _sda = 1;
@@ -88,15 +92,15 @@
         _sda.input();          //release the data line
         _sda.mode(OpenDrain);
         
-        wait_us(1);
+        wait_us(_frequency_delay);
 
         for ( int n = 8; n > 0; --n ) {
             _scl=1;            //set clock high
-            wait_us(1);
+            wait_us(_frequency_delay);
             byte |= _sda << (n-1); //read the bit
-            wait_us(1);
+            wait_us(_frequency_delay);
             _scl=0;            //set clock low
-            wait_us(1);
+            wait_us(_frequency_delay);
         }
 
         _sda.output();         //take data line back
@@ -106,10 +110,10 @@
 
     inline void giveAck() {
         _sda.output();
-        wait_us(1);
+        wait_us(_frequency_delay);
         _sda = 0;
         _scl = 1;
-        wait_us(1);
+        wait_us(_frequency_delay);
         _scl = 0;
         _sda = 1;
 
@@ -121,12 +125,12 @@
         _scl = 1;
         _sda.input();
         _sda.mode(OpenDrain);
-        wait_us(1);
+        wait_us(_frequency_delay);
         _scl = 0;
 
         if(_sda != 0){return false;}
 
-        wait_us(1);
+        wait_us(_frequency_delay);
         return true;
     }
 
@@ -134,6 +138,7 @@
     DigitalInOut _scl;
     
     uint8_t _device_address;
+    uint32_t _frequency_delay;
 };
 
 #endif
\ No newline at end of file