MCP2515_Demo.cpp

cmake_minimum_required(VERSION 3.12)
find_package(PropWare REQUIRED)
 
project(MCP2515_Demo)
 
create_simple_executable(${PROJECT_NAME} MCP2515_Demo.cpp)

 
#include <PropWare/PropWare.h>
#include <PropWare/hmi/output/printer.h>
#include <PropWare/serial/can/mcp2515.h>
 
using PropWare::Port;
using PropWare::Pin;
using PropWare::MCP2515;
using PropWare::SPI;
 
static const Port::Mask MOSI       = Port::Mask::P0;
static const Port::Mask MISO       = Port::Mask::P1;
static const Port::Mask SCLK       = Port::Mask::P2;
static const Port::Mask CS         = Port::Mask::P7;
static const Port::Mask CLOCK_MASK = Port::Mask::P8;
 
static const uint8_t messages[][6] = {
    "Hello",
    "David",
    "Katie"
};
 
void handle(const PropWare::ErrorCode err) {
    if (err) {
        pwOut.printf("ERROR!!! %d\n", err);
        while (1)
            waitcnt(0);
    }
}
 
void read(MCP2515 &can, const MCP2515::BufferNumber bufferNumber) {
    if (can.check_receive_buffer(bufferNumber)) {
        uint8_t buffer[MCP2515::MAX_DATA_BYTES];
        uint8_t bytesRead;
        can.read_message(bufferNumber, &bytesRead, buffer);
        pwOut << "Message: `" << (const char *) buffer << "`\n";
    } else {
        pwOut << "No message\n";
    }
}
 
int main() {
    // Instantiate the SPI bus and CAN controller instances
    const SPI spi(MOSI, MISO, SCLK);
    MCP2515   can(spi, CS);
 
    // We'll use the Propeller's hardware counters as a clock source for the MCP2515
    const Pin clock(CLOCK_MASK, Pin::Dir::OUT);
    clock.start_hardware_pwm(8000000);
 
    // Start the MCP2515 running a 1 Mbaud and in "loopback" mode. This means that all messages "sent" will be
    // immediately looped back into the receive buffers. This is great for testing your configuration while still at
    // your desk, to ensure that the filters and masks have been correctly configured, along with any other
    // configuration. Once ready, remove the optional `mode` parameter and connect to your live system.
    handle(can.start(MCP2515::BaudRate::BAUD_1000KBPS, MCP2515::Mode::LOOPBACK));
 
    // Set up the filters and masks so that only message ID 2 is allowed through
    handle(can.set_mask(MCP2515::BufferNumber::BUFFER_0, PropWare::WORD_0));
    handle(can.set_filter(MCP2515::FilterNumber::FILTER_0, 2));
 
    pwOut << "Expected message received:\n";
    handle(can.send_message(2, 6, messages[0]));
    read(can, MCP2515::BufferNumber::BUFFER_0);
 
    pwOut << "Message should _not_ be received!\n";
    handle(can.send_message(3, 6, messages[1]));
    read(can, MCP2515::BufferNumber::BUFFER_0);
 
    pwOut << "Expected message received:\n";
    handle(can.send_message(2, 6, messages[2]));
    read(can, MCP2515::BufferNumber::BUFFER_0);
}