Diff: RWDModule.cpp

Revision:

2:37fafd1e1a20

Parent:

1:e96aaf4d5c55

Child:

3:60db4ab4dafe

--- a/RWDModule.cpp	Tue Jul 13 10:37:26 2010 +0000
+++ b/RWDModule.cpp	Tue Jul 13 16:11:29 2010 +0000
@@ -1,11 +1,35 @@
+
+/*
+Copyright (c) 2010 Donatien Garnier (donatiengar [at] gmail [dot] com)
+ 
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+ 
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+ 
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
 #include "RWDModule.h"
 
 RWDModule::RWDModule(PinName tx, PinName rx, PinName cts) : m_serial(tx, rx), m_cts(cts),
 m_cmd(0), m_paramsBuf(NULL), m_respBuf(NULL), m_pos(0), m_paramsLen(0), m_respLen(0), m_ackOk(0), m_ackOkMask(0), m_ack(0), m_state(READY)
 {
-  m_serial.attach(this, &RWDModule::intTx, Serial::TxIrq);
-  m_serial.attach(this, &RWDModule::intRx, Serial::RxIrq);
-  m_cts.fall(this, &RWDModule::intClearToSend);
+  //Setup interrupts
+  m_serial.attach(this, &RWDModule::intTx, Serial::TxIrq); //Serial port writeable
+  m_serial.attach(this, &RWDModule::intRx, Serial::RxIrq); //Serial port readable
+  m_cts.fall(this, &RWDModule::intClearToSend); //Clear To Send: can send a command
 }
 
 RWDModule::~RWDModule()
@@ -13,49 +37,50 @@
 
 }
 
-void RWDModule::command(byte cmd, const byte* params, int paramsLen, byte* resp, int respLen, byte ackOk, byte ackOkMask) //Ack Byte is not included in the resp buf
+void RWDModule::command(uint8_t cmd, const uint8_t* params, int paramsLen, uint8_t* resp, size_t respLen, uint8_t ackOk, size_t ackOkMask) //Ack Byte is not included in the resp buf
 {
-  if(!ready())
+  if(!ready()) //If reader is not ready, does not submit another command yet
     return;
+  
+  //Setup command
   m_cmd = cmd;
-  m_paramsBuf = (byte*) params;
+  
+  //Setup parameters
+  m_paramsBuf = (uint8_t*) params;
   m_paramsLen = paramsLen;
+  
+  //Setup response
   m_respBuf = resp;
   m_respLen = respLen;
+  
+  //Pos in buf is 0
   m_pos = 0;
+  
+  //Setup ack requirements
   m_ackOk = ackOk;
   m_ackOkMask = ackOkMask;
+  
   m_state = CMD_QUEUED;
 }
   
 bool RWDModule::ready()
 {
-#if 0
-  static int lastState;
-  if(m_state != lastState)
-  {
-    printf("State %d\n", m_state);
-    lastState = m_state;
-    if(m_state==RECEIVING_ACK)
-      printf("Ack %02x\n", m_ack);
-  }
-#endif
   return (m_state==READY);
 }
    
-bool RWDModule::result(byte* pAck /*= NULL*/)
+bool RWDModule::result(uint8_t* pAck /*= NULL*/)
 {
-  if(!ready())
+  if(!ready()) //Has command returned yet?
     return false;
-  if(pAck)
+  if(pAck) //If pointer is passed, return reader's ack
     *pAck = m_ack;
-  return ((m_ack & m_ackOkMask) == m_ackOk);
+  return ((m_ack & m_ackOkMask) == m_ackOk); //Return whether the reader returned an error or OK ack
 }
 
 void RWDModule::intClearToSend()
 {
   //Start sending command when Clear To Send falls
-  if(m_state == CMD_QUEUED)
+  if(m_state == CMD_QUEUED) //Is there a command to be sent?
   {
     m_state = SENDING_CMD;
     intTx(); //Start sending command
@@ -69,15 +94,15 @@
     return;  
   if(m_pos==0) //Must send command-byte first
     m_serial.putc((char)m_cmd);
-  while(true)
+  while(true) //Send payload
   {
-    if(m_pos >= m_paramsLen)
+    if(m_pos >= m_paramsLen) //Payload sent completely?
     {
       m_pos = 0;
-      m_state = WAITING_FOR_ACK;
+      m_state = WAITING_FOR_ACK; //Next step
       return;
     }
-    m_serial.putc((char)m_paramsBuf[m_pos]);
+    m_serial.putc((char)m_paramsBuf[m_pos]); //Send payload byte
     m_pos++;
   }
 }
@@ -86,23 +111,23 @@
 {
   if(m_state == WAITING_FOR_ACK) //Get answer
   {
-    m_ack = m_serial.getc();
-    if( (m_ack & m_ackOkMask) != m_ackOk )
+    m_ack = m_serial.getc(); //Get Ack
+    if( (m_ack & m_ackOkMask) != m_ackOk ) //Check if an error is returned
     {
-      m_state = READY;
+      m_state = READY; //If yes, transfer is completed and result() will return false
       return;
     }
     if(m_respLen)
     {
-      m_state = RECEIVING_ACK;
+      m_state = RECEIVING_ACK; //Ack OK, now need to get response
     }
     else
     {
-      m_state = READY;
+      m_state = READY; //Ack OK, end of transfer
       return;
     }
   }
-  if(m_state != RECEIVING_ACK) //Error
+  if(m_state != RECEIVING_ACK) //Error, should not happen
   {
     while(m_serial.readable())
       m_serial.getc(); //Dump these bytes
@@ -110,12 +135,12 @@
   }
   while(m_serial.readable()) //Read payload
   {
-    m_respBuf[m_pos] = (byte) m_serial.getc();
+    m_respBuf[m_pos] = (uint8_t) m_serial.getc(); //Read byte and put it in resp buf
     m_pos++;
     if(m_pos >= m_respLen)
     {
       m_pos = 0;
-      m_state = READY;
+      m_state = READY; //End of transfer, response retrieved with success
     }
   }
 }