RWDModule.cpp

00001 
00002 /*
00003 Copyright (c) 2010 Donatien Garnier (donatiengar [at] gmail [dot] com)
00004  
00005 Permission is hereby granted, free of charge, to any person obtaining a copy
00006 of this software and associated documentation files (the "Software"), to deal
00007 in the Software without restriction, including without limitation the rights
00008 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00009 copies of the Software, and to permit persons to whom the Software is
00010 furnished to do so, subject to the following conditions:
00011  
00012 The above copyright notice and this permission notice shall be included in
00013 all copies or substantial portions of the Software.
00014  
00015 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00016 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00017 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00018 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00019 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00020 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00021 THE SOFTWARE.
00022 */
00023 
00024 #include "RWDModule.h"
00025 
00026 RWDModule::RWDModule(PinName tx, PinName rx, PinName cts) : m_serial(tx, rx), m_cts(cts),
00027 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)
00028 {
00029   //Setup baudrate
00030   m_serial.baud(9600);
00031   //Setup interrupts
00032   m_serial.attach(this, &RWDModule::intTx, Serial::TxIrq); //Serial port writeable
00033   m_serial.attach(this, &RWDModule::intRx, Serial::RxIrq); //Serial port readable
00034   m_cts.fall(this, &RWDModule::intClearToSend); //Clear To Send: can send a command
00035 }
00036 
00037 RWDModule::~RWDModule ()
00038 {
00039 
00040 }
00041 
00042 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
00043 {
00044   if(!ready()) //If reader is not ready, does not submit another command yet
00045     return;
00046   
00047   //Setup command
00048   m_cmd = cmd;
00049   
00050   //Setup parameters
00051   m_paramsBuf = (uint8_t*) params;
00052   m_paramsLen = paramsLen;
00053   
00054   //Setup response
00055   m_respBuf = resp;
00056   m_respLen = respLen;
00057   
00058   //Pos in buf is 0
00059   m_pos = 0;
00060   
00061   //Setup ack requirements
00062   m_ackOk = ackOk;
00063   m_ackOkMask = ackOkMask;
00064   
00065   m_state = CMD_QUEUED;
00066 }
00067   
00068 bool RWDModule::ready()
00069 {
00070   return (m_state==READY);
00071 }
00072    
00073 bool RWDModule::result(uint8_t* pAck /*= NULL*/)
00074 {
00075   if(!ready()) //Has command returned yet?
00076     return false;
00077   if(pAck) //If pointer is passed, return reader's ack
00078     *pAck = m_ack;
00079   return ((m_ack & m_ackOkMask) == m_ackOk); //Return whether the reader returned an error or OK ack
00080 }
00081 
00082 void RWDModule::intClearToSend()
00083 {
00084   //Start sending command when Clear To Send falls
00085   if(m_state == CMD_QUEUED) //Is there a command to be sent?
00086   {
00087     m_state = SENDING_CMD;
00088     intTx(); //Start sending command
00089   }
00090 }
00091 
00092 
00093 void RWDModule::intTx()
00094 {
00095   if(m_state != SENDING_CMD)
00096     return;  
00097   if(m_pos==0) //Must send command-byte first
00098     m_serial.putc((char)m_cmd);
00099   while(true) //Send payload
00100   {
00101     if(m_pos >= m_paramsLen) //Payload sent completely?
00102     {
00103       m_pos = 0;
00104       m_state = WAITING_FOR_ACK; //Next step
00105       return;
00106     }
00107     m_serial.putc((char)m_paramsBuf[m_pos]); //Send payload byte
00108     m_pos++;
00109   }
00110 }
00111 
00112 void RWDModule::intRx()
00113 {
00114   if(m_state == WAITING_FOR_ACK) //Get answer
00115   {
00116     m_ack = m_serial.getc(); //Get Ack
00117     if( (m_ack & m_ackOkMask) != m_ackOk ) //Check if an error is returned
00118     {
00119       m_state = READY; //If yes, transfer is completed and result() will return false
00120       return;
00121     }
00122     if(m_respLen)
00123     {
00124       m_state = RECEIVING_ACK; //Ack OK, now need to get response
00125     }
00126     else
00127     {
00128       m_state = READY; //Ack OK, end of transfer
00129       return;
00130     }
00131   }
00132   if(m_state != RECEIVING_ACK) //Error, should not happen
00133   {
00134     while(m_serial.readable())
00135       m_serial.getc(); //Dump these bytes
00136     return; 
00137   }
00138   while(m_serial.readable()) //Read payload
00139   {
00140     m_respBuf[m_pos] = (uint8_t) m_serial.getc(); //Read byte and put it in resp buf
00141     m_pos++;
00142     if(m_pos >= m_respLen)
00143     {
00144       m_pos = 0;
00145       m_state = READY; //End of transfer, response retrieved with success
00146     }
00147   }
00148 }