Revision 0:6d75da25c179, committed 2012-07-14

Comitter:

bborredon

Date:

Sat Jul 14 08:20:07 2012 +0000

Commit message:

[mbed] converted /I2c/PCF8574

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PCF8574.cpp	Sat Jul 14 08:20:07 2012 +0000
@@ -0,0 +1,210 @@
+/***********************************************************
+Author: Bernard Borredon
+Date: 27 december 2011
+Version: 1.0
+************************************************************/
+#include "PCF8574.h"
+
+// Local object address
+static PCF8574 *pt_pcf8574;
+
+// User callback function address
+static void (*_ptf)(uint8_t data,PCF8574 *o)= NULL;
+
+// Callback
+static void _InterruptCB(void)
+{
+  uint8_t data = 0;
+  bitset<8> data_p,val;
+  bitset<8> changed;
+  uint8_t i;
+  
+  // Read PCF8574 port (to acknowledge interrupt)
+  data = pt_pcf8574->read();
+  
+  // Set bits that have changed
+  pt_pcf8574->getIntrData(data_p,changed);
+  changed = 0;
+  val = data;
+  for(i = 0;i < 8;i++) {
+     if(val[i] != data_p[i])
+       changed[i] = 1;
+  }
+  pt_pcf8574->setIntrData(val,changed);
+  
+  // Call user callback, if any with port value
+  if(_ptf != NULL)
+    _ptf(data,pt_pcf8574);
+}
+
+// Constructor
+PCF8574::PCF8574(PinName sda,PinName scl,uint8_t address, bool typeA) : _i2c(sda, scl)
+{
+  _errnum = PCF8574_NoError;
+  _intr = NULL;
+  pt_pcf8574 = NULL;
+  _intr_data = 0xFF;
+  _intr_bits_changed = 0;
+  _intr_flag = 0;
+  
+  // Set the address
+  if(typeA) {  // PCF8574A
+    _PCF8574_address = 0x70;
+  }
+  else {       // PCF8574
+    _PCF8574_address = 0x40;
+  }
+  
+  _address = address;
+  
+  // Check address validity (between 0 and 7)
+  if(address > 7) {
+    _errnum = PCF8574_BadAddress;
+  }
+  
+  // Shift address
+  _address = _address << 1;
+  
+  // Set I2C frequency (100 MHz)
+  _i2c.frequency(100000);
+}
+
+// Read IO port
+uint8_t PCF8574::read(void)
+{
+  uint8_t data;
+  int ack;
+  
+  // Check error
+  if(_errnum) 
+    return(0);
+  
+  // No error
+  _errnum = PCF8574_NoError;
+    
+  // Read port
+  ack = _i2c.read(_PCF8574_address | _address,(char *)&data,sizeof(data));
+  
+  // Check error
+  if(ack != 0) {
+    _errnum = PCF8574_I2cError;
+  }
+  
+  return(data);
+}
+
+// Write IO port
+void PCF8574::write(uint8_t data)
+{
+  int ack;
+  
+  // Check error
+  if(_errnum) 
+    return;
+ 
+  // No error   
+  _errnum = PCF8574_NoError;
+    
+  // Write port
+  ack = _i2c.write(_PCF8574_address | _address,(char *)&data,sizeof(data));
+  
+  // Check error
+  if(ack != 0) {
+    _errnum = PCF8574_I2cError;
+  }
+}
+
+// Write IO pin
+void PCF8574::write(uint8_t pin, uint8_t value)
+{
+  uint8_t data;
+  
+  // Read IO port value
+  data = read();
+  
+  // Change bit pin
+  if(value)
+    BIT_SET(data,pin);
+  else
+    BIT_CLEAR(data,pin);
+    
+  // Write new IO port data
+  write(data);
+}
+
+// Write to IO pins with a bitset and a bitset mask
+void PCF8574::write(bitset<8> data, bitset<8> mask)
+{
+  uint8_t i;
+  bitset<8> nd;
+  
+  nd = (bitset<8>) read();
+  for(i = 0;i < 8;i++) {
+     if(mask[i])
+       nd[i] = data[i];
+  }
+  
+  write((uint8_t) nd.to_ulong());
+}
+
+// Set pin and callback interrupt
+void PCF8574::interrupt(PinName intr,void (*ftpr)(uint8_t, PCF8574 *))
+{
+  
+  // Check error
+  if(_errnum) 
+    return;
+    
+  // No error
+  _errnum = PCF8574_NoError;
+    
+  // Create InterruptIn instance if needed
+  if(_intr == NULL) {
+    _intr = new InterruptIn(intr);
+    
+    // Set InterruptIn callback
+    if(_intr != NULL)
+      _intr->fall(_InterruptCB);
+    else
+      _errnum = PCF8574_IntrError;
+  }
+  
+  _ptf = ftpr; // User callback address
+  pt_pcf8574 = this; // Object instance
+  _intr_data = read(); // IO port value
+  _intr_flag = 1; // Function called
+}
+
+// Get current error number
+uint8_t PCF8574::getError(void)
+{ 
+  return(_errnum);
+}
+
+// Memorize IO port value and bits that have changed when interrupt
+ void PCF8574::setIntrData(bitset<8> data, bitset<8> changed)
+ {
+   _intr_data = data;
+   _intr_bits_changed = changed;
+ }
+ 
+ // Get IO port value and bits that have changed when interrupt
+ void PCF8574::getIntrData(bitset<8>& data, bitset<8>& changed)
+ {
+   data = _intr_data;
+   changed = _intr_bits_changed;
+ }
+
+// Redefine () operator
+PCF8574::operator uint8_t() 
+{ 
+  return read(); 
+}
+ 
+// Redefine = operator
+PCF8574 &PCF8574::operator=(uint8_t data)
+{
+  write((int)data);
+  
+  return(*this);
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PCF8574.h	Sat Jul 14 08:20:07 2012 +0000
@@ -0,0 +1,202 @@
+#ifndef PCF8574__H_
+#define PCF8574__H_
+
+// Includes
+#include <string> 
+#include <bitset>
+
+#include "mbed.h"
+
+// Example
+/*
+#include <string>
+
+#include "mbed.h"
+#include "PCF8574.h"
+
+#define PCF8574_ADDR 0    // I2c PCF8574 address is 0x00
+
+static void myerror(std::string msg)
+{
+  printf("Error %s\n",msg.c_str());
+  exit(1);
+}
+
+void pcf8574_it(uint8_t data, PCF8574 *o)
+{
+  printf("PCF8574 interrupt data = %02x\n",data);
+}
+
+DigitalOut led2(LED2);
+
+int main() 
+{
+  PCF8574 pcf(p9,p10,PCF8574_ADDR,true);  // Declare PCF8574A i2c with sda = p9 and scl = p10
+  uint8_t data;
+  
+  led2 = 0;
+  
+  // Set all IO port bits to 1 to enable inputs and test error
+  data = 0xFF;
+  pcf = data;
+  if(pcf.getError() != 0)
+    myerror(pcf.getErrorMessage());
+  
+  // Assign interrupt function to pin 17  
+  pcf.interrupt(p17,&pcf8574_it);
+  
+  if(pcf.getError() != 0)
+    myerror(pcf.getErrorMessage());
+  
+  // Get IO port (switch is used to flip bit 1)
+  while(1) {
+             wait(2.0);
+             data = pcf;
+             if(pcf.getError() != 0)
+               myerror(pcf.getErrorMessage());
+             led2 = !led2;
+  }
+
+  return(0);
+}
+*/
+
+// Defines
+#define PCF8574_NoError     0x00
+#define PCF8574_BadAddress  0x01
+#define PCF8574_I2cError    0x02
+#define PCF8574_IntrError   0x03
+
+#define PCF8574_MaxError       4
+
+#ifndef BIT_SET
+#define BIT_SET(x,n) (x=x | (0x01<<n))
+#endif
+#ifndef BIT_TEST
+#define BIT_TEST(x,n) (x & (0x01<<n))
+#endif
+#ifndef BIT_CLEAR
+#define BIT_CLEAR(x,n) (x=x & ~(0x01<<n))
+#endif
+#ifndef BIT_GET
+#define BIT_GET(x,n) ((x >>n) & 0x1)
+#endif
+
+static std::string _ErrorMessagePCF8574[PCF8574_MaxError] = {
+                                                              "",
+                                                              "Bad chip address",
+                                                              "I2C error (nack)",
+                                                              "Unable to create InterruptIn instance"
+                                                            };
+
+// Class
+class PCF8574 {
+public:               
+    /*
+     * Constructor, initialize the PCF8574 on i2c interface.
+     * @param sda : sda i2c pin (PinName)
+     * @param scl : scl i2c pin (PinName)
+     * @param address : PCF8574 address between 0 and 7 (uint8_t) 
+     * @param typeA : PCF8574A if true, default false (bool)
+     * @return none
+    */
+    PCF8574(PinName sda, PinName scl, uint8_t address, bool typeA = false);
+
+    /*
+     * Read the IO pins level
+     * @param : none
+     * @return port value (uint8_t)
+    */
+    uint8_t read(void);
+    
+    /*
+     * Write to the IO pins
+     * @param data : The 8 bits to write to the IO port (uint8_t)
+     * @return none
+    */
+    void write(uint8_t data);
+    
+    /*
+     * Write to individual IO pin
+     * @param pin : The pin number between 0 and 7 (uint8_t)
+     * @param value : The pin value (uint8_t)
+     * @return none
+    */
+    void write(uint8_t pin, uint8_t value);
+    
+    /*
+     * Write to IO pins with a bitset and a bitset mask (only bits set in mask are written)
+     * @param data : The biset to write to the IO port (bitset<8>)
+     * @param mask : The biset to write mask (bitset<8>)
+     * @return none
+    */
+    void write(bitset<8> data, bitset<8> mask);
+    
+    /*
+     * Interrupt IO callback called when PCF8574 IO pins changed (falling edge)
+     * @param intr : pin name connected to PCF8574 int pin (PinName)
+     * @param ftpr : user callback function (void ftpr(unit8_t data, PCF8574 *o)).
+     *                 data : PCF8574 IO port value
+     *                 o    : object instance address
+     * @return none
+    */
+    void interrupt(PinName intr,void (*ftpr)(uint8_t data, PCF8574 *o));
+    
+    /*
+     * Get current error message
+     * @param  : none
+     * @return current error message(std::string)
+    */
+    std::string getErrorMessage(void)
+    { 
+      if(_errnum < PCF8574_MaxError)
+        return(_ErrorMessagePCF8574[_errnum]);
+      else
+        return("errnum out of range");
+    }
+    
+    /*
+     * Get the current error number (PCF8574_NoError if no error)
+     * @param  : none
+     * @return current error number (uint8_t)
+    */
+    uint8_t getError(void);
+     
+    /*
+     * Memorize data IO port value and bits that have changed when interrupt
+     * @param data : data IO port value when interrupt (bitset<8>)
+     * @param changed : bits that have changed (bitset<8>) 
+     * @return none
+    */
+     void setIntrData(bitset<8> data, bitset<8> changed);
+     
+    /*
+     * Get data IO port value when and bits that have changed when interrupt 
+     * @param data : data IO port value when interrupt (bitset<8>&) 
+     * @param changed : bits that have changed (bitset<8>&)
+     * @return none
+    */
+     void getIntrData(bitset<8>& data, bitset<8>& changed);
+    
+    /*
+     *Operator () (read)
+    */
+    operator uint8_t();
+    
+    /* 
+     *Operator = (write)
+    */
+    PCF8574 &operator=(uint8_t data);
+    
+private:
+    I2C _i2c; // Local i2c communication interface instance
+    int _address; // Local pcf8574 i2c address
+    int _PCF8574_address; // PCF8574 address
+    uint8_t _errnum; // Error number
+    bitset<8> _intr_data; // IO port value when interrupt
+    bitset<8> _intr_bits_changed; // Bits that have changed on interrupt 
+    InterruptIn *_intr; // Internal InterruptIn object address
+    uint8_t _intr_flag; // interrupt function has been called
+};
+
+#endif
\ No newline at end of file