Stephen Davis
Library set up as dummy module on mbed to mimic Nordic.
Diff: rs485.cpp
- Revision:
- 0:226550611f0d
- Child:
- 1:d6b18299a715
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/rs485.cpp Mon Dec 12 23:06:58 2016 +0000
@@ -0,0 +1,404 @@
+#include <string.h>
+#include <stdio.h>
+
+#include "rs485.h"
+
+
+#define PRINTPACKETDEBUG
+#define DEVADDRESS 0xF0
+#define DEBUG
+
+static list_t functionList = { .index = 0 };
+
+
+Packet buildPacket;
+static unsigned int buffPtr;
+static unsigned char buffer[128+1];
+int checksum;
+int pState = START;
+int returnState;
+unsigned int plength;
+unsigned char command;
+int message;
+// extern int message;
+
+// extern unsigned char packetBuffer[128];
+// extern unsigned int packetBufferSize;
+static unsigned char packetBuffer[128];
+static unsigned int packetBufferSize;
+
+extern int Bluetooth_ReceivePacket( Packet *_packet );
+extern int Bluetooth_SendChar( unsigned char );
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+unsigned char RegisterCommand( unsigned char _command , void (*_function)( unsigned char *) ){
+ functionList.list[ functionList.index ].function = _function;
+ functionList.list[ functionList.index ].command = _command;
+ functionList.index++;
+ return 0;
+}
+
+int CheckFunction( Packet *_packet ){
+ int i = 0;
+ void (*Caller)(unsigned char *);
+ for( i = 0 ; i < functionList.index ; i++ ){
+ if( _packet->command == functionList.list[i].command ){
+ Caller = (void (*)(unsigned char *))functionList.list[i].function;
+ Caller( (unsigned char *)_packet->packetData );
+ return 1;
+ }
+ }
+ return 0;
+}
+
+void RS495_Init( void ){
+
+}
+
+static void SendAck( void ){
+ #ifdef DEBUG
+ pc.printf( "\n\rAck Sent.\n\r" );
+ #endif // DEBUG
+ unsigned char ack = ACKCHAR;
+ Bluetooth_SendChar( ack );
+}
+
+static void SendNack( void ){
+ #ifdef DEBUG
+ pc.printf( "\n\rNack Sent.\n\r" );
+ #endif // DEBUG
+ unsigned char nack = NAKCHAR;
+ Bluetooth_SendChar( nack );
+}
+
+static int ProcessPacket( Packet *_packet ){
+ return Bluetooth_ReceivePacket( _packet );
+}
+
+void SendMessage( void ){
+ int j = 0;
+ Bluetooth_SendChar( packetBuffer[ j++ ] );
+ while( j < packetBufferSize ){
+ if( packetBuffer[ j ] == STARTPACK ){
+ Bluetooth_SendChar( ESCAPE ); // #SCD Added this line, I think it should be here
+ Bluetooth_SendChar( 0x01 );
+ j++;
+ }
+ else if( packetBuffer[ j ] == ESCAPE ){
+ Bluetooth_SendChar( ESCAPE );
+ Bluetooth_SendChar( ESCAPE );
+ j++;
+ }
+ else if( packetBuffer[ j ] == STARTPOLL ){
+ Bluetooth_SendChar( ESCAPE );
+ Bluetooth_SendChar( 0x02 );
+ j++;
+ }
+ else{
+ Bluetooth_SendChar( packetBuffer[ j++ ] );
+ }
+ }
+}
+
+/******************************************************************************
+ * Function void setResponse(int, int, int)
+ *
+ * This function sets the feedback information to be send in the master device.
+ *
+ * PreCondition: None
+ *
+ * Input: '_packet' - prebuilt packet to send
+ *
+ * Output: None
+ *
+ * Side Effects: None
+ *
+ *****************************************************************************/
+ void SetResponse( Packet *_packet ){
+ packetBufferSize = getFormattedPacket(&_packet, packetBuffer);
+ message = 1;
+}
+
+/******************************************************************************
+ * Function void SerialHandler(unsigned char )
+ *
+ * This function handles the received data from the Serial Communication.
+ *
+ * PreCondition: None
+ *
+ * Input: 'RXByte' - the received data from Serial Communication
+ *
+ *
+ * Output: None
+ *
+ * Side Effects: None
+ *
+ *****************************************************************************/
+void SerialHandler(unsigned char RXByte){
+
+ #ifdef DEBUG
+ pc.printf( "RXByte: %x" , RXByte );
+ #endif
+
+
+ // check the incoming byte for special characters
+ if( RXByte == STARTPACK ){ // start of packet byte
+ #ifdef DEBUG
+ pc.printf( " - STARTBYTE\n\r" );
+ #endif
+ pState = DEVICEADDRESS; // move on to check the destination address
+ buffPtr = 0; // reset buffer pointer
+ buffer[buffPtr++] = STARTPACK; // load RXByte into buffer
+ checksum = STARTPACK; // add to checksum
+ return; // exit function, will be called again in next state
+ }
+ else if( RXByte == STARTPOLL ){ // poll byte
+ #ifdef DEBUG
+ pc.printf( " - STARTPOLL\n\r" );
+ #endif
+ pState = POLL; // move on to check the distination address
+ return; // exit function, will be called again in next state
+ }
+ else if( RXByte == ESCAPE ){ // escape byte
+ if( pState == HANDLEESCAPE ){ // if this is the second escape byte in a row
+ }
+ else{
+ #ifdef DEBUG
+ pc.printf( " - ESCAPE TO " );
+ #endif
+ returnState = pState; // if this is the first escape byte, record the current state
+ pState = HANDLEESCAPE; // change state
+ return; // exit function, will be called again in next state
+ }
+ }
+
+ if( pState == HANDLEESCAPE ){ // if entering here RXByte needs to be unescaped
+ switch( RXByte ){
+ case 1: // unescape a 0x7F/Start of packet byte
+ RXByte = 0x7F;
+ #ifdef DEBUG
+ pc.printf( " -> %x" , RXByte );
+ #endif
+ break;
+
+ case 2: // unescape a 0x8F/Poll byte
+ RXByte = 0x8F;
+ #ifdef DEBUG
+ pc.printf( " -> %x" , RXByte );
+ #endif
+ break;
+
+ case ESCAPE: // unescape a 0x8E/Escape byte
+ RXByte = 0x8E;
+ #ifdef DEBUG
+ pc.printf( " -> %x" , RXByte );
+ #endif
+ break;
+ }
+ pState = returnState; // change back to state before escape byte received
+ }
+
+ switch( pState ){
+
+ case POLL: // of switch( pState ) // poll state checks RXByte to see if there is an address match
+
+
+ if( RXByte == DEVADDRESS ){ // if the device is being polled...
+ #ifdef DEBUG
+ pc.printf( " - Address Match: %x" , DEVADDRESS );
+ #endif
+
+ if( message ){ // if a message is available send it
+ #ifdef DEBUG
+ pc.printf( " - Message to Send\n\r" );
+ #endif
+ SendMessage(); // #SCD haven't tested this
+ pState = RESPONSE; // change state to wait for ACK or NACK
+ }
+ else{ // device is pulled but no message to be sent
+ #ifdef DEBUG
+ pc.printf( " - No message to Send\n\r" );
+ #endif
+ SendAck(); // just send an ACK
+ pState = START;
+ }
+ }
+ else{
+ pState = START; // device not addressed, do nothing
+ }
+ break;
+
+ case START: // of switch( pState ) // this state really does nothing and just waits for
+ pState = START; // if the device is not addressed in a packet
+ break;
+
+ case RESPONSE: // of switch( pState ) // a message was sent it last state and now this state is
+
+ switch( RXByte ){
+
+ case ACKCHAR: // ACK is received - message successful, clear message to be sent
+ #ifdef DEBUG
+ pc.printf( " - ACK RECEIVED\n\r" );
+ #endif
+ message = 0;
+ pState = START;
+ break;
+
+ case NAKCHAR: // NACK is received - message not successful
+ #ifdef DEBUG
+ pc.printf( " - NACK RECEIVED\n\r" );
+ #endif
+ if( message ){ // if a message still needs to be sent, send again
+ SendMessage();
+ message = 0; // clear message after this seconda attempt to prevent too many tries
+ pState = RESPONSE; // set state to come by here next time around
+ }
+ else{ // if a NACK is received for the second time in a row
+ //#error #SCD // throw an error and do not resend
+ pc.printf( "Received two NACKs from master. Message failed.\n\r" );
+ }
+ break;
+
+ default:
+ #ifdef DEBUG
+ pc.printf( " - EXPECTED ACK or NACK\n\r" );
+ #endif
+ pState = START; // if neither an ACK nor NACK is received, reset state
+ break;
+
+ }
+ break;
+
+ case DEVICEADDRESS: // of switch( pState ) // checks to see if device is addressed in current packet
+ #ifdef DEBUG
+ pc.printf( " - DEVICEADDRESS\n\r" );
+ #endif
+
+ if( RXByte == DEVADDRESS ){
+ #ifdef PRINT_ADDRESS_MATCH
+ pc.printf( "Address Match: %d\n\r" , DEVADDRESS );
+ #endif
+
+ pState = SOURCEADD; // next state is grabbing the source device ID
+ buffer[buffPtr++] = RXByte; // add RXByte to buffer
+ buildPacket.deviceID = RXByte; // build packet
+ checksum += RXByte; // add RXByte to checksum
+ }
+ else{
+ pState = START; // if device is not addressed reset state
+ }
+
+ break;
+
+ case SOURCEADD: // of switch( pState ) // records the source address of the packet
+ #ifdef DEBUG
+ pc.printf( " - SOURCEADD\n\r" );
+ #endif
+
+ pState = COLLECTCOMMAND; // state advances to get the command byte
+ buffer[buffPtr++] = RXByte; // add RXByte to buffer
+ buildPacket.sourceID = RXByte; // build packet
+ checksum += RXByte; // add RXByte to checksum
+ break;
+
+ case COLLECTCOMMAND: // of switch( pState )// records the command byte of the packet
+ #ifdef DEBUG
+ pc.printf( " - COMMAND\n\r" );
+ #endif
+
+ command = RXByte; // record command byte
+ buildPacket.command = RXByte; // build packet
+ pState = COLLECTCOUNT1; // advance to get packetLength
+ buffer[buffPtr++] = RXByte; // add RXByte to buffer
+ checksum += RXByte; // add RXByte to checksum
+ break;
+
+ case COLLECTCOUNT1: // of switch( pState ) // records first byte of packetLength
+ #ifdef DEBUG
+ pc.printf( " - COUNT MSB \n\r" );
+ #endif
+
+ pState = COLLECTCOUNT2; // advance state to get next byte of packetLength
+ plength = RXByte;
+ plength <<= 8; // store byte in packetLength #SCD is this storing correctly?
+ buffer[buffPtr++] = RXByte; // add RXByte to buffer
+ checksum += RXByte; // add RXByte to checksum
+ break;
+
+ case COLLECTCOUNT2: // of switch( pState ) // records second byte of packetLength
+ #ifdef DEBUG
+ pc.printf( " - COUNT LSB\n\r" );
+ #endif
+
+ plength += RXByte; // add RXByte to packetLength total
+ buildPacket.packetLength = plength; // build packet
+ buffer[buffPtr++] = RXByte; // add RXByte to buffer
+ checksum += RXByte; // add RXByte to checksum
+ if( plength == 0 ) // if packetLength is 0, advance to checksum state
+ pState = COLLECTCHECKSUM;
+ else // otherwise move on to collect packet payload
+ pState = COLLECTPACKET;
+ break;
+
+ case COLLECTPACKET: // of switch( pState ) // collects packetData, enters this state multiple times
+ #ifdef DEBUG
+ pc.printf( " - PACKETDATA \n\r" );
+ #endif
+
+ plength--; // decrement length
+ buffer[buffPtr++] = RXByte; // add RXByte to buffer
+ checksum += RXByte; // add RXByte to checksum
+
+ if( plength == 0 ){ // if collected all packetData advance state
+ pState = COLLECTCHECKSUM;
+ }
+ break;
+
+ case COLLECTCHECKSUM:// of switch( pState ) // collects checksum of packet and checks for validity
+ #ifdef DEBUG
+ pc.printf( " - CHECKSUM\n\r" );
+ #endif
+ memcpy( &buildPacket.packetData , &buffer[6] , buildPacket.packetLength );
+
+ if( RXByte == ( ( checksum* - 1 ) & 0xFF ) ){ // compares RXByte with LSB of checksum
+ message = 0; // if checksum is correct clear message #SCD could a message be waiting?
+ memset(packetBuffer, '\0', 128); // clear packetBuffer
+
+ buffer[buffPtr++] = RXByte; // add RXByte to buffer
+
+ #ifdef PRINTPACKETDEBUG
+ pc.printf( "Receive Buffer: " ); // debug print received packet
+ unsigned int i = 0;
+ for( i = 0 ; i < buffPtr ; i++ ){
+ pc.printf( "%x " , buffer[ i ] );
+ }
+ pc.printf( "\n\r" );
+ #endif
+
+ int errorResult = ProcessPacket( &buildPacket );
+
+ if( errorResult == -1 ){ // check to make sure function performed properly
+ //#SCD setResponse(RPIADDRESS, command, ERRORCOMMAND);
+ }
+ SendAck(); // send an ACK
+ }
+ else{
+ SendNack(); // if checksum is not corret, send a NACK
+ }
+
+ pState = START;
+ break;
+
+ } // end switch( pState )
+
+} // end serial2Handler function
+
+
+
+#ifdef __cplusplus
+}
+#endif