com.github.pires.obd.commands.control.TroubleCodesObdCommand Maven / Gradle / Ivy

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OBD Java API compatible with ELM327.
There is a newer version: 1.0
/**
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
/**
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package com.github.pires.obd.commands.control;

import java.io.IOException;
import java.io.InputStream;
import com.github.pires.obd.commands.ObdCommand;
import com.github.pires.obd.enums.AvailableCommandNames;

/**
 * It is not needed no know how many DTC are stored.
 * Because when no DTC are stored response will be NO DATA
 * And where are more messages it will be stored in frames that have 7 bytes.
 * In one frame are stored 3 DTC.
 * If we find out DTC P0000 that mean no message are we can end.
 */
public class TroubleCodesObdCommand extends ObdCommand {

  protected final static char[] dtcLetters = {'P', 'C', 'B', 'U'};
  protected final static char[] hexArray = "0123456789ABCDEF".toCharArray();

  private StringBuffer codes = null;

  public TroubleCodesObdCommand() {
    super("03");

    codes = new StringBuffer();
  }

  /**
   * Copy ctor.
   *
   * @param other a {@link com.github.pires.obd.commands.control.TroubleCodesObdCommand} object.
   */
  public TroubleCodesObdCommand(TroubleCodesObdCommand other) {
    super(other);
    codes = new StringBuffer();
  }

  @Override
  protected void fillBuffer() {
  }

  @Override
  protected void performCalculations() {

    String workingData = getResult().replaceAll("[\r\n]", "");

    int begin = 0; // start at 2nd byte

    for (int i = 0; begin < workingData.length(); i++) {
      begin += 2;

      for (int j = 0; j < 3; j++) {
        String dtc = "";

        byte b1 = hexStringToByteArray(workingData.charAt(begin));

        int ch1 = ((b1 & 0xC0) >> 6);
        int ch2 = ((b1 & 0x30) >> 4);

        dtc += dtcLetters[ch1];
        dtc += hexArray[ch2];

        begin++;

        dtc += workingData.substring(begin, begin + 3);

        if (dtc.equals("P0000")) {
          return;
        }

        codes.append(dtc);
        codes.append('\n');
        begin += 3;
      }
    }
  }

  private byte hexStringToByteArray(char s) {
    return (byte) ((Character.digit(s, 16) << 4));
  }

  /**
   * @return the formatted result of this command in string representation.
   */
  public String formatResult() {
    return codes.toString();
  }

  @Override
  protected void readRawData(InputStream in) throws IOException {
    byte b = 0;
    StringBuilder res = new StringBuilder();

    // read until '>' arrives
    while ((char) (b = (byte) in.read()) != '>') {
      if ((char) b != ' ') {
        res.append((char) b);
      }
    }

    rawData = res.toString().trim();

  }

  @Override
  public String getFormattedResult() {
    return codes.toString();
  }

  @Override
  public String getName() {
    return AvailableCommandNames.TROUBLE_CODES.getValue();
  }

}