Add new CAN API (#1036)

2026-06-22 01:11:42 +00:00 · 2018-05-21 16:09:38 -07:00
parent 55b0fe0082
commit 680aabbe7c
19 changed files with 1545 additions and 1 deletions
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/CAN.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/CAN.java
@@ -0,0 +1,134 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2018 FIRST. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+package edu.wpi.first.wpilibj;
+
+import java.io.Closeable;
+
+import edu.wpi.first.wpilibj.hal.CANAPIJNI;
+
+/**
+ * High level class for interfacing with CAN devices conforming to
+ * the standard CAN spec.
+ *
+ * <p>No packets that can be sent gets blocked by the RoboRIO, so all methods
+ * work identically in all robot modes.
+ *
+ * <p>All methods are thread safe, however the CANData object passed into the
+ * read methods and the byte[] passed into the write methods need to not
+ * be modified for the duration of their respective calls.
+ */
+public class CAN implements Closeable {
+  public static final int kTeamManufacturer = 8;
+  public static final int kTeamDeviceType = 10;
+
+  private int m_handle;
+
+  /**
+   * Create a new CAN communication interface with the specific device ID.
+   * The device ID is 6 bits (0-63)
+   */
+  public CAN(int deviceId) {
+    m_handle = CANAPIJNI.initializeCAN(kTeamManufacturer, deviceId, kTeamDeviceType);
+  }
+
+  /**
+   * Closes the CAN communication.
+   */
+  @Override
+  public void close() {
+    if (m_handle != 0) {
+      CANAPIJNI.cleanCAN(m_handle);
+    }
+  }
+
+  /**
+   * Write a packet to the CAN device with a specific ID. This ID is 10 bits.
+   *
+   * @param data The data to write (8 bytes max)
+   * @param apiId The API ID to write.
+   */
+  public void writePacket(byte[] data, int apiId) {
+    CANAPIJNI.writeCANPacket(m_handle, data, apiId);
+  }
+
+  /**
+   * Write a repeating packet to the CAN device with a specific ID. This ID is 10 bits.
+   * The RoboRIO will automatically repeat the packet at the specified interval
+   *
+   * @param data The data to write (8 bytes max)
+   * @param apiId The API ID to write.
+   * @param repeatMs The period to repeat the packet at.
+   */
+  public void writePacketRepeating(byte[] data, int apiId, int repeatMs) {
+    CANAPIJNI.writeCANPacketRepeating(m_handle, data, apiId, repeatMs);
+  }
+
+  /**
+   * Stop a repeating packet with a specific ID. This ID is 10 bits.
+   *
+   * @param apiId The API ID to stop repeating
+   */
+  public void stopPacketRepeating(int apiId) {
+    CANAPIJNI.stopCANPacketRepeating(m_handle, apiId);
+  }
+
+  /**
+   * Read a new CAN packet. This will only return properly once per packet
+   * received. Multiple calls without receiving another packet will return false.
+   *
+   * @param apiId The API ID to read.
+   * @param data Storage for the received data.
+   * @return True if the data is valid, otherwise false.
+   */
+  public boolean readPacketNew(int apiId, CANData data) {
+    return CANAPIJNI.readCANPacketNew(m_handle, apiId, data);
+  }
+
+  /**
+   * Read a CAN packet. The will continuously return the last packet received,
+   * without accounting for packet age.
+   *
+   * @param apiId The API ID to read.
+   * @param data Storage for the received data.
+   * @return True if the data is valid, otherwise false.
+   */
+  public boolean readPacketLatest(int apiId, CANData data) {
+    return CANAPIJNI.readCANPacketLatest(m_handle, apiId, data);
+  }
+
+  /**
+   * Read a CAN packet. The will return the last packet received until the
+   * packet is older then the requested timeout. Then it will return false.
+   *
+   * @param apiId The API ID to read.
+   * @param timeoutMs The timeout time for the packet
+   * @param data Storage for the received data.
+   * @return True if the data is valid, otherwise false.
+   */
+  public boolean readPacketTimeout(int apiId, int timeoutMs, CANData data) {
+    return CANAPIJNI.readCANPacketTimeout(m_handle, apiId, timeoutMs, data);
+  }
+
+  /**
+   * Read a CAN packet. The will return the last packet received until the
+   * packet is older then the requested timeout. Then it will return false.
+   * The period parameter is used when you know the packet is sent at specific
+   * intervals, so calls will not attempt to read a new packet from the
+   * network until that period has passed. We do not recommend users use this
+   * API unless they know the implications.
+   *
+   * @param apiId The API ID to read.
+   * @param timeoutMs The timeout time for the packet
+   * @param periodMs The usual period for the packet
+   * @param data Storage for the received data.
+   * @return True if the data is valid, otherwise false.
+   */
+  public boolean readPeriodicPacket(int apiId, int timeoutMs, int periodMs, CANData data) {
+    return CANAPIJNI.readCANPeriodicPacket(m_handle, apiId, timeoutMs, periodMs, data);
+  }
+}