// ----------------------------------------------------------------------------
// Configure the mailbox to send a CAN message.
// Low level function called by sendMessage and by Tx Interrupt.
static void
sendMailbox(const xpcc::can::Message& message, uint32_t mailboxId)
{
CAN_TxMailBox_TypeDef* mailbox = &CAN2->sTxMailBox[mailboxId];
if (message.isExtended()) {
mailbox->TIR = message.identifier << 3 | CAN_TI0R_IDE;
}
else {
mailbox->TIR = message.identifier << 21;
}
if (message.isRemoteTransmitRequest()) {
mailbox->TIR |= CAN_TI0R_RTR;
}
// Set up the DLC
mailbox->TDTR = message.getLength();
// Set up the data field (copy the 8x8-bits into two 32-bit registers)
const uint8_t * ATTRIBUTE_MAY_ALIAS data = message.data;
mailbox->TDLR = reinterpret_cast<const uint32_t *>(data)[0];
mailbox->TDHR = reinterpret_cast<const uint32_t *>(data)[1];
// Request transmission
mailbox->TIR |= CAN_TI0R_TXRQ;
}
// ----------------------------------------------------------------------------
// Low level function to receive a message from mailbox.
// Called by Rx Interrupt or by getMessage.
static void
readMailbox(xpcc::can::Message& message, uint32_t mailboxId)
{
CAN_FIFOMailBox_TypeDef* mailbox = &CAN2->sFIFOMailBox[mailboxId];
uint32_t rir = mailbox->RIR;
if (rir & CAN_RI0R_IDE) {
message.identifier = rir >> 3;
message.setExtended();
}
/* Low level function:
* Called by interrupt or by getMessage to receive a message */
static void
readMessageObject(xpcc::can::Message & message, uint8_t messageObjectId)
{
// NXP's data structure for sending CAN messages
CAN_MSG_OBJ msg_obj;
// Which Message Object to receive
msg_obj.msgobj = messageObjectId;
// Read Message Object from CAN controller
(*xpcc::lpc::Can::rom)->pCAND->can_receive(&msg_obj);
// Is extended Identifier?
if (msg_obj.mode_id & CAN_MSGOBJ_EXT) {
message.setExtended();
// The lower 29 bits are the extended identifier
message.identifier = msg_obj.mode_id & 0x1fffffff;
}
else {
message.setExtended(false);
// The lower 11 bits are the standard identifier
message.identifier = msg_obj.mode_id & 0x7ff;
}
// Is RTR ?
message.setRemoteTransmitRequest( (msg_obj.mode_id & CAN_MSGOBJ_RTR) );
// Get DLC
message.length = msg_obj.dlc;
// Copy Data
// TODO Use memcpy or reinterpret_cast
for (uint8_t ii = 0; ii < message.length; ++ii)
{
message.data[ii] = msg_obj.data[ii];
}
}
/* Low level function:
* Use a Message Object to send a message */
static void
sendMessageObject(const xpcc::can::Message & message, uint8_t messageObjectId)
{
// NXP's data structure for sending CAN messages
CAN_MSG_OBJ msg_obj;
// Which Message Object to use, valid numbers are 0 to 31.
// In this class 16 to 31 are used.
msg_obj.msgobj = messageObjectId;
// Mode and Identifier
msg_obj.mode_id = message.identifier | CAN_MSGOBJ_STD;
if (message.isExtended()) {
msg_obj.mode_id |= CAN_MSGOBJ_EXT;
}
if (message.isRemoteTransmitRequest()) {
msg_obj.mode_id |= CAN_MSGOBJ_RTR;
}
// Mask unused for transmission
msg_obj.mask = 0x0;
// Set up the DLC
msg_obj.dlc = message.getLength();
// Copy the data.
// TODO reinterpret_cast or memcpy
for (uint8_t ii = 0; ii < msg_obj.dlc; ++ii) {
msg_obj.data[ii] = message.data[ii];
}
// Really send the message
(*xpcc::lpc::Can::rom)->pCAND->can_transmit(&msg_obj);
}
// ----------------------------------------------------------------------------
static void
displayMessage(const xpcc::can::Message& message)
{
static uint32_t receiveCounter = 0;
receiveCounter++;
display.clear();
display.setFont(xpcc::font::Assertion);
display << " CAN Demo";
display.drawLine(0, 13, 102, 13);
display.setCursor(0, 16);
display.setFont(xpcc::font::FixedWidth5x8);
display.printf("id =%lx\n", message.getIdentifier());
if (message.isExtended()) {
display << " extended";
}
else {
display << " standard";
}
if (message.isRemoteTransmitRequest()) {
display << ", rtr";
}
display << xpcc::endl;
display << "dlc =" << message.getLength() << xpcc::endl;
if (!message.isRemoteTransmitRequest())
{
display << "data=";
uint8_t x = display.getCursor().getX();
for (uint32_t i = 0; i < message.getLength(); ++i) {
if (i == 4) {
// wrap around to the next line
display << xpcc::endl;
display.setCursorX(x);
}
display << xpcc::hex << message.data[i] << xpcc::ascii << ' ';
}
display << xpcc::endl;
}
display << "# received=" << receiveCounter;
display.update();
}