/* * Author: Jon Trulson * Copyright (c) 2016 Intel Corporation. * * This program and the accompanying materials are made available under the * terms of the The MIT License which is available at * https://opensource.org/licenses/MIT. * * SPDX-License-Identifier: MIT */ import upm_mcp2515.MCP2515; public class MCP2515_TXRX_Example { public static void main(String[] args) throws InterruptedException { // ! [Interesting] // by default we just receive packets Boolean do_tx = false; if (args.length > 0) do_tx = true; // Instantiate a MCP2515 on SPI bus 0 using a hw CS pin (-1). MCP2515 sensor = new MCP2515(0, -1); // NOTE: This example assumes that only two devices are connected // to the CAN bus, and that both devices are running this example; // one in TX (transmit) mode, and one in RX (receive) mode. // If this is not the case, then in rx mode you may see other // packets from other devices, or not, depending on whether the // speed is correct for the network. In tx mode, errors may be // generated on the bus, especially if the CAN bus speed does not // match the rest of the network. // You should start the receiver example first. The transmitter // example will fail after about 5 seconds (timeout) of not being // able to transmit a message. while (true) { if (do_tx) { // lets build up a packet and try loading it (8 bytes max). String myPayload = "01234567"; System.out.println("Loading a packet of 8 numbers (0-7) into a TX buffer..."); sensor.loadTXBuffer(upm_mcp2515.MCP2515_TX_BUFFER_T.MCP2515_TX_BUFFER0, 0, false, false, myPayload); // now lets try to transmit it System.out.println("Transmitting packet..."); sensor.transmitBuffer(upm_mcp2515.MCP2515_TX_BUFFER_T.MCP2515_TX_BUFFER0, true); System.out.println("Transmit successful"); System.out.println(); Thread.sleep(500); } else { // There should now be a packet waiting for us in RXB0 if (sensor.rxStatusMsgs() == upm_mcp2515.MCP2515_RXMSG_T.MCP2515_RXMSG_RXB0) { System.out.println("Packet received in RXB0, decoding..."); // now lets retrieve and print it sensor.getRXMsg(upm_mcp2515.MCP2515_RX_BUFFER_T.MCP2515_RX_BUFFER0); sensor.printMsg(); System.out.println(); } Thread.sleep(100); } } // ! [Interesting] } }