PilotI2c.cpp

#include "PilotI2c.h"

#include <Defines.h>
#include <Wire.h>


//CRC-8 - based on the CRC8 formulas by Dallas/Maxim
//code released under the therms of the GNU GPL 3.0 license
byte CRC8(const byte *data, byte len) {
  byte crc = 0x00;
  while (len--) {
    byte extract = *data++;
    for (byte tempI = 8; tempI; tempI--) {
      byte sum = (crc ^ extract) & 0x01;
      crc >>= 1;
      if (sum) {
        crc ^= 0x8C;
      }
      extract >>= 1;
    }
  }
  return crc;
}

template <typename O,typename T> unsigned int SerialWrite (O& oSerial, const T& o)  // for uart and i2c :-)
{
  oSerial.write((byte *) &o, sizeof (o));
  byte iCRC8 = CRC8((byte *) &o,sizeof (o));
  oSerial.write(iCRC8);
  return sizeof (o);
}

template <typename C,typename S, typename I> bool SerialRead(C& oSerial,S& o, I iAvailable) // for uart and i2c :-)
{
  if (iAvailable < sizeof(o)+1 ) 
    return false;
  
  byte buff[sizeof(o)];
  byte* p = buff;
  for (unsigned int i=0; i < sizeof o; i++)
      *p++ = oSerial.read();
  byte iMust = CRC8(buff,sizeof(o) );
  byte iCRC8 = oSerial.read();
  if (iMust != iCRC8) 
    return false;
  memcpy(&o,buff,sizeof(o));
  return true;
}


PilotI2c* pPilotI2c = NULL;

void RequestEventPilotI2c()
{
	if (pPilotI2c)	pPilotI2c->RequestEvent();
}

void ReceiveEventPilotI2c(int iAvail) 
{
	if (pPilotI2c)	pPilotI2c->ReceiveEvent(iAvail);
}


PilotI2c::PilotI2c(Hoverboard& r) : Pilot(r)
{

}

// function that executes whenever data is requested by master
void PilotI2c::RequestEvent() 
{
  iRequests++;

  oSlave2Master.iStatus = oHoverboard.IsReady() * HOVERSTATUS_Ready;
  oSlave2Master.fRpm1 = oHoverboard.GetRpmPerVolt();
  oSlave2Master.fCurrent1 = oHoverboard.GetDcCurrent();

  SerialWrite(Wire,oSlave2Master);     // to send struct with crc: from openPanasonicBike
}

void PilotI2c::ReceiveEvent(int iAvail) 
{
	iReceived++;
	switch(iAvail-1)	// CRC takes one bytes
	{
	case sizeof(Server2Hover1) :
		if (SerialRead(Wire,oMaster2Slave1,iAvail))
		{
			oSlave2Master.iCmdLast = oMaster2Slave1.iCmd;
			switch (oMaster2Slave1.iCmd)
			{
			case CMD1_Speed:
				oHoverboard.MoveLP(oMaster2Slave1.fValue);
				break;
			}
			return;
		}
		break;
	case sizeof(Server2Hover2) :
		if (SerialRead(Wire,oMaster2Slave2,iAvail))
		{
			oSlave2Master.iCmdLast = oMaster2Slave2.iCmd;
			return;
		}
		break;
	}
    OUT2("\nCRC fail. avail: ",iAvail);
}


void PilotI2c::init(byte iI2cAdress)
{
	pPilotI2c = this;
	Wire.begin(iI2cAdress);                // join i2c bus with address #8
	// ArduinoCore:	nvic_irq_enable(I2C0_EV_IRQn, 1, 3);
	// 				nvic_irq_enable(I2C0_ER_IRQn, 1, 2);

	nvic_irq_enable(I2C0_EV_IRQn, 3, 3);	// to not block IrqMotor nvic_irq_enable(XY_IRQn, 1, 2);
	nvic_irq_enable(I2C0_ER_IRQn, 3, 3);

	Wire.onReceive(ReceiveEventPilotI2c); // receiveEvent called when data from master received
	Wire.onRequest(RequestEventPilotI2c); // called when master requests data from this slave
}