#include "mcp2515.h"
/*RXB0's data registers:*/
unsigned char RXB0D[8]={RXB0D0,RXB0D1,RXB0D2,RXB0D3,RXB0D4,RXB0D5,RXB0D6,RXB0D7};
/*TXB0's data registers:*/
unsigned char TXB0D[8]={TXB0D0,TXB0D1,TXB0D2,TXB0D3,TXB0D4,TXB0D5,TXB0D6,TXB0D7};
void MCP2515_Init(void)
{
unsigned char dummy;
/*First initialize the SPI periphere*/
/*Then initialize the MCP2515.Step as follow:
1>Get into configuration mode by reset MCP2515 or write the bit of CANCTRL.REQOP.
2>Check the CANSTAT by ReadByte_MCP2515(CANSTAT) if MCP2515 is already into configuration mode.
3>Configurate the registers to set the baudrate:CN1,CN2,CN3.
4>Configurate TXRTSCTRL to set the function of TXnRTS pin.
5>Configurate TRXBnCTRL to set the pirority of transmit mailbox:TXB0,TXB1,TXB2.
6>Configurate TXBn'SID ,EID and DLC.This step can configurate when you are in normal mode.
7>Configurate RXFnSIDH and RXFnSIDL to resceive the specific ID.
8>Configurate RXMnSIDH and RXMnSIDL to mask the RXFnSID's ID.
9>Configurate CANINTE to enable or disable the interrupts.
10>Return to the normal mode and double check if it is return to the normal mode by CANSTAT.
*/
/*Flip into the Configuration Mode*/
MCP2515_Reset();
_delay_(0x4000);/* 1ms _delay_ using Fcpu = 16Mhz*/
//Set the baudrate
//set CNF1,SJW=00,lengthe is 1TQ,BRP=49,TQ=[2*(BRP+1)]/Fsoc=2*50/8M=12.5us
SendByte_MCP2515(CNF1,CAN_125Kbps);
//set CNF2,SAM=0,caputre one time,PHSEG1=(2+1)TQ=3TQ,PRSEG=(0+1)TQ=1TQ
SendByte_MCP2515(CNF2,0x80|PHSEG1_3TQ|PRSEG_1TQ);
//set CNF3,PHSEG2=(2+1)TQ=3TQ,when CANCTRL.CLKEN=1,set CLKOUT pin to output
SendByte_MCP2515(CNF3,PHSEG2_3TQ);
/*
3 Transimit Buffers:TXB0,TXB1,TXB2
2 Receive Buffers:RXB0,RXB1
6 ID Filter:RXF0~RXF5
2 ID Mask Regieter:RXM0,RXM1
*/
//configurate RXB0' registers
// SendByte_MCP2515(RXB0CTRL,0x60);//Receive all frames from CAN bus
SendByte_MCP2515(RXB0CTRL,0x20);//RXB0 just receive the standard frames
SendByte_MCP2515(RXF0SIDH,0xFF);//Fileter register
SendByte_MCP2515(RXF0SIDL,0xE0);//Just receive ID=0x7FF frame
SendByte_MCP2515(RXF1SIDH,0xFD);//Fileter register
SendByte_MCP2515(RXF1SIDL,0xC0);//Just receive ID=0x7EE frame
SendByte_MCP2515(RXM0SIDH,0xFF);//Mask register
SendByte_MCP2515(RXM0SIDL,0xE0);
//Configurate TXB0's ID and DLC registers
SendByte_MCP2515(TXB0SIDH,0xFF);//Standard ID
SendByte_MCP2515(TXB0SIDL,0xE0);//Standard ID
SendByte_MCP2515(TXB0DLC,DLC_1);//DLC
/*Set the RXB0 or RXB1 interrupt enableling*/
// SendByte_MCP2515(CANINTE,RX0IE);//Enable RXB0 interrupt
SendByte_MCP2515(CANCTRL,REQOP_NORMAL | CLKOUT_ENABLED);//Go into the normal mode
dummy=ReadByte_MCP2515(CANSTAT);
if (OPMODE_NORMAL != (dummy & 0xE0))
SendByte_MCP2515(CANCTRL,REQOP_NORMAL | CLKOUT_ENABLED);//If normal ok
}
/**
* @brief Reset the MCP2515 then U go into the configruation mode
* @param none
* @retval none
*/
void MCP2515_Reset(void)
{
CS_LOW();
SPI_Send(SPI_RESET);
CS_HIGH();
}
/**
* @brief Modify the bit of the register
* @param Add:Address of register
* @param Mask:1-->U can modify the corresponding bit;0-->U can not modify the corresponding bit
* @param Data:the data U need to be sent from MCU to MCP2515
* @retval none
*/
void MCP2515_BitModify(unsigned char Addr,unsigned char Mask,unsigned char Data)
{
CS_LOW();
SPI_Send(SPI_BIT_MODIFY);
SPI_Send(Addr);
SPI_Send(Mask);
SPI_Send(Data);
CS_HIGH();
}
/**
* @brief Send a byte to MCP2515 through SPI to return corresponding status you need
* @param Add:Address of register
* @param Data:the data U need to be sent from MCU to MCP2515
* @retval none
*/
void SendByte_MCP2515(unsigned char Addr,unsigned char Data)
{
CS_LOW();
SPI_Send(SPI_WRITE);
SPI_Send(Addr);
SPI_Send(Data);
CS_HIGH();
}
/**
* @brief Send a command to MCP2515 through SPI to return corresponding status you need
* @param CMD:command
* @retval Data:Data from MCP2515'SO pin
*/
unsigned char ReadByte_MCP2515(unsigned char Addr)
{
unsigned char Data;
CS_LOW();
SPI_Send(SPI_READ);
SPI_Send(Addr);
Data = SPI_Receive();
CS_HIGH();
return Data;
}
/**
* @brief Send a command to MCP2515 through SPI to return corresponding status you need
* @param CMD:
SPI_RX_STATUS;
SPI_READ_STATUS;
SPI_READ_RX;
* @retval Data:the status you need
*/
unsigned char SPI_CMD_MCP2515(unsigned char CMD)
{
unsigned char Data;
CS_LOW();
SPI_Send(CMD);
Data = SPI_Receive();
CS_HIGH();
return Data;
}
/**
* @brief Read 8 bytes to CAN bus
* @param CAN_TX_Buf:the address of data'indicator,8bytes
* @retval none
*/
void CAN_Send8bytes(unsigned char *CAN_TX_Buf)
{
unsigned char tempdata;
tempdata=ReadByte_MCP2515(SPI_READ_STATUS);
SendByte_MCP2515(TXB0D0,CAN_TX_Buf[0]);
SendByte_MCP2515(TXB0D1,CAN_TX_Buf[1]);
SendByte_MCP2515(TXB0D2,CAN_TX_Buf[2]);
SendByte_MCP2515(TXB0D3,CAN_TX_Buf[3]);
SendByte_MCP2515(TXB0D4,CAN_TX_Buf[4]);
SendByte_MCP2515(TXB0D5,CAN_TX_Buf[5]);
SendByte_MCP2515(TXB0D6,CAN_TX_Buf[6]);
SendByte_MCP2515(TXB0D7,CAN_TX_Buf[7]);
if(tempdata&0x04)//check the TXREQ bit
{
_delay_(0x4000);
MCP2515_BitModify(TXB0CTRL,0x80,0x00);//clear TXREQ bit
while(SPI_CMD_MCP2515(SPI_READ_STATUS)&0x04);//wait until TXREQ bit matchs 0
}
CS_LOW();
SPI_Send(SPI_RTS_TXB0);//TXB0 send-request
CS_HIGH();
}
/**
* @brief Send a byte to CAN bus by TXB0
* @param Data:data to be sent
* @retval none
*/
void CAN_SendOneByte(unsigned char Data)
{
unsigned char tempdata;
/*Test the driver between MCP2515 and the SPI periphere :tempdata<--------------*/
tempdata=SPI_CMD_MCP2515(SPI_READ_STATUS);
if(tempdata&0x04)//check the TXREQ bit
{
_delay_(0x4000);
MCP2515_BitModify(TXB0CTRL,0x08,0x00);//clear TXREQ bit
while(SPI_CMD_MCP2515(SPI_READ_STATUS)&0x04);//wait until TXREQ bit matchs 0
}
SendByte_MCP2515(TXB0D0,Data);
CS_LOW();
SPI_Send(SPI_RTS_TXB0);//TXB0 send-request
CS_HIGH();
}
/**
* @brief Receive a byte from MCP2515 RXB0
* @param none
* @retval Data:return the effectively data from RXB0
*/
unsigned char CAN_Receive_onebyte()
{
unsigned char tempdata;
tempdata=SPI_CMD_MCP2515(SPI_READ_STATUS);//confirm receive data=RXB0IF
if(tempdata&0x01)
{
tempdata=SPI_CMD_MCP2515(SPI_RX_STATUS);
if(tempdata&0x40)//true means RXB0's standard frame
{
tempdata=ReadByte_MCP2515(RXB0D0);
}
else
{tempdata=254;}//no standard frame receive
MCP2515_BitModify(CANINTF,0x01,0x00);
}
else
{tempdata=255;}//no frame receive
return tempdata;
}
/**
* @brief Send n bytes with a given standard ID corresponding to frame type
* @param CAN_TX_Buf: data to be sent
* @param DLC:DLC<=8
* @param SID:<=0x7FF
* @param CAN_FrameType:CAN_STD,CAN_RTR
* @retval None
*/
void CAN_SendData(unsigned char *CAN_TX_Buf,Frame_TypeDef *Frame )
{
unsigned char tempdata;
unsigned char HSID,LSID;
if(Frame->Type==CAN_STD)
{
/*Set the ID of the frame*/
HSID=(unsigned char)(Frame->SID>>3);
LSID=(unsigned char)((Frame->SID<<5)&0xE0);
SendByte_MCP2515(TXB0SIDH,HSID);
SendByte_MCP2515(TXB0SIDL,LSID);
/*Set the DLC and the type of the frame*/
SendByte_MCP2515(TXB0DLC,Frame->DLC|CAN_STD);
/*Write the data into the TXB0 data registers */
for(tempdata=0;tempdata<Frame->DLC;tempdata++)
SendByte_MCP2515(TXB0D[tempdata],CAN_TX_Buf[tempdata]);
/* SendByte_MCP2515(TXB0D0,CAN_TX_Buf[0]);
SendByte_MCP2515(TXB0D1,CAN_TX_Buf[1]);
SendByte_MCP2515(TXB0D2,CAN_TX_Buf[2]);
SendByte_MCP2515(TXB0D3,CAN_TX_Buf[3]);
SendByte_MCP2515(TXB0D4,CAN_TX_Buf[4]);
SendByte_MCP2515(TXB0D5,CAN_TX_Buf[5]);
SendByte_MCP2515(TXB0D6,CAN_TX_Buf[6]);
SendByte_MCP2515(TXB0D7,CAN_TX_Buf[7]);*/
}
else /*if(CAN_FrameType==CAN_RTR)*/
{
/*Set the ID of the frame*/
HSID=(unsigned char)(Frame->SID>>3);
LSID=(unsigned char)((Frame->SID<<5)&0xE0);
SendByte_MCP2515(TXB0SIDH,HSID);
SendByte_MCP2515(TXB0SIDL,LSID);
/*Set the type of the frame*/
SendByte_MCP2515(TXB0DLC,CAN_RTR);
}
tempdata=SPI_CMD_MCP2515(SPI_READ_STATUS);
if(tempdata&0x04)
{
_delay_(0x4000);
MCP2515_BitModify(TXB0CTRL,0x80,0x00);
while(SPI_CMD_MCP2515(SPI_READ_STATUS)&0x04);
}
/*Send the SPI_RTS_TXB0 request command to MCP2515 to send the data loaded in the data register*/
CS_LOW();
SPI_Send(SPI_RTS_TXB0);
CS_HIGH();
}
/**
* @brief Receive n bytes from MCP2515 RXB0
* @param none
* @retval Data:return the effectively data from RXB0
*/
unsigned char CAN_ReceiveData(unsigned char *CAN_RX_Buf,Frame_TypeDef *Frame)
{
unsigned char tempdata;
unsigned int CAN_ID;
// tempdata=SPI_CMD_MCP2515(SPI_READ_STATUS);//check if it is received a frame
tempdata=SPI_CMD_MCP2515(SPI_RX_STATUS);
if(tempdata&0x40)//RXB0
{
CAN_ID=(unsigned int)((ReadByte_MCP2515(RXB0SIDH))<<8);
CAN_ID|=(unsigned int)(ReadByte_MCP2515(RXB0SIDL));
CAN_ID>>=5;
/*Check the CAN_ID you received that if it is matched with the SID you wish*/
if(CAN_ID==Frame->SID)
{
// _delay_(0x4000);
for(tempdata=0;tempdata<Frame->DLC;tempdata++)
CAN_RX_Buf[tempdata]=ReadByte_MCP2515(RXB0D[tempdata]);
/* CAN_RX_Buf[0]=ReadByte_MCP2515(RXB0D0);
CAN_RX_Buf[1]=ReadByte_MCP2515(RXB0D1);
CAN_RX_Buf[2]=ReadByte_MCP2515(RXB0D2);
CAN_RX_Buf[3]=ReadByte_MCP2515(RXB0D3);
CAN_RX_Buf[4]=ReadByte_MCP2515(RXB0D4);
CAN_RX_Buf[5]=ReadByte_MCP2515(RXB0D5);
CAN_RX_Buf[6]=ReadByte_MCP2515(RXB0D6);
CAN_RX_Buf[7]=ReadByte_MCP2515(RXB0D7);*/
MCP2515_BitModify(CANINTF,0x01,0x00);
}
else
{
return 0;//ID is not correct
}
return 1;//receive ok
}
else
return 2;//no standard frame receive
}