前言

本篇文章主要演示android的串口通訊功能，其中需要使用serialport模塊(下載鏈接)，注意: 串口通訊需要root權(quán)限,需要將應(yīng)用設(shè)置成‘a(chǎn)ndroid:sharedUserId=“android.uid.system”’即可，如果出現(xiàn)串口通訊無(wú)法訪問(wèn)設(shè)備，首先看串口名稱與波特率是否一致，如果都一致看看是否是打開(kāi)串口就失敗了，如果出現(xiàn)無(wú)權(quán)限的情況，可能是Android開(kāi)發(fā)板不支持與該設(shè)備通訊，可以考慮讓嵌入式工程師使用單片機(jī)提供通訊訪問(wèn)能力，本篇文章只是演示android使用modbus協(xié)議，具體協(xié)議理論可以參考其它文章，這里不在講解。

一、導(dǎo)入模塊

implementation project(path: ':serialport')

二、協(xié)議相關(guān)

1. CRC16

package com.jujiang.fyc.myttftwo.utils.modbus;

import java.util.Arrays;

public class CRC16 {
    private static final byte[] crc16_tab_h = { (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40,
            (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x01, (byte) 0xC0, (byte) 0x80,
            (byte) 0x41, (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x01, (byte) 0xC0,
            (byte) 0x80, (byte) 0x41, (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x00,
            (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41,
            (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x00, (byte) 0xC1, (byte) 0x81,
            (byte) 0x40, (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x01, (byte) 0xC0,
            (byte) 0x80, (byte) 0x41, (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x01,
            (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41,
            (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x01, (byte) 0xC0, (byte) 0x80,
            (byte) 0x41, (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x00, (byte) 0xC1,
            (byte) 0x81, (byte) 0x40, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x00,
            (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41,
            (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x00, (byte) 0xC1, (byte) 0x81,
            (byte) 0x40, (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x01, (byte) 0xC0,
            (byte) 0x80, (byte) 0x41, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x00,
            (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41,
            (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x00, (byte) 0xC1, (byte) 0x81,
            (byte) 0x40, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x01, (byte) 0xC0,
            (byte) 0x80, (byte) 0x41, (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x00,
            (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41,
            (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x01, (byte) 0xC0, (byte) 0x80,
            (byte) 0x41, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x00, (byte) 0xC1,
            (byte) 0x81, (byte) 0x40, (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x01,
            (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41,
            (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x01, (byte) 0xC0, (byte) 0x80,
            (byte) 0x41, (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x00, (byte) 0xC1,
            (byte) 0x81, (byte) 0x40, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x00,
            (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41,
            (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x00, (byte) 0xC1, (byte) 0x81,
            (byte) 0x40, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x00, (byte) 0xC1,
            (byte) 0x81, (byte) 0x40, (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x01,
            (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41,
            (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40, (byte) 0x00, (byte) 0xC1, (byte) 0x81,
            (byte) 0x40, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x00, (byte) 0xC1,
            (byte) 0x81, (byte) 0x40, (byte) 0x01, (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x01,
            (byte) 0xC0, (byte) 0x80, (byte) 0x41, (byte) 0x00, (byte) 0xC1, (byte) 0x81, (byte) 0x40 };

    private static final byte[] crc16_tab_l = { (byte) 0x00, (byte) 0xC0, (byte) 0xC1, (byte) 0x01,
            (byte) 0xC3, (byte) 0x03, (byte) 0x02, (byte) 0xC2, (byte) 0xC6, (byte) 0x06, (byte) 0x07,
            (byte) 0xC7, (byte) 0x05, (byte) 0xC5, (byte) 0xC4, (byte) 0x04, (byte) 0xCC, (byte) 0x0C,
            (byte) 0x0D, (byte) 0xCD, (byte) 0x0F, (byte) 0xCF, (byte) 0xCE, (byte) 0x0E, (byte) 0x0A,
            (byte) 0xCA, (byte) 0xCB, (byte) 0x0B, (byte) 0xC9, (byte) 0x09, (byte) 0x08, (byte) 0xC8,
            (byte) 0xD8, (byte) 0x18, (byte) 0x19, (byte) 0xD9, (byte) 0x1B, (byte) 0xDB, (byte) 0xDA,
            (byte) 0x1A, (byte) 0x1E, (byte) 0xDE, (byte) 0xDF, (byte) 0x1F, (byte) 0xDD, (byte) 0x1D,
            (byte) 0x1C, (byte) 0xDC, (byte) 0x14, (byte) 0xD4, (byte) 0xD5, (byte) 0x15, (byte) 0xD7,
            (byte) 0x17, (byte) 0x16, (byte) 0xD6, (byte) 0xD2, (byte) 0x12, (byte) 0x13, (byte) 0xD3,
            (byte) 0x11, (byte) 0xD1, (byte) 0xD0, (byte) 0x10, (byte) 0xF0, (byte) 0x30, (byte) 0x31,
            (byte) 0xF1, (byte) 0x33, (byte) 0xF3, (byte) 0xF2, (byte) 0x32, (byte) 0x36, (byte) 0xF6,
            (byte) 0xF7, (byte) 0x37, (byte) 0xF5, (byte) 0x35, (byte) 0x34, (byte) 0xF4, (byte) 0x3C,
            (byte) 0xFC, (byte) 0xFD, (byte) 0x3D, (byte) 0xFF, (byte) 0x3F, (byte) 0x3E, (byte) 0xFE,
            (byte) 0xFA, (byte) 0x3A, (byte) 0x3B, (byte) 0xFB, (byte) 0x39, (byte) 0xF9, (byte) 0xF8,
            (byte) 0x38, (byte) 0x28, (byte) 0xE8, (byte) 0xE9, (byte) 0x29, (byte) 0xEB, (byte) 0x2B,
            (byte) 0x2A, (byte) 0xEA, (byte) 0xEE, (byte) 0x2E, (byte) 0x2F, (byte) 0xEF, (byte) 0x2D,
            (byte) 0xED, (byte) 0xEC, (byte) 0x2C, (byte) 0xE4, (byte) 0x24, (byte) 0x25, (byte) 0xE5,
            (byte) 0x27, (byte) 0xE7, (byte) 0xE6, (byte) 0x26, (byte) 0x22, (byte) 0xE2, (byte) 0xE3,
            (byte) 0x23, (byte) 0xE1, (byte) 0x21, (byte) 0x20, (byte) 0xE0, (byte) 0xA0, (byte) 0x60,
            (byte) 0x61, (byte) 0xA1, (byte) 0x63, (byte) 0xA3, (byte) 0xA2, (byte) 0x62, (byte) 0x66,
            (byte) 0xA6, (byte) 0xA7, (byte) 0x67, (byte) 0xA5, (byte) 0x65, (byte) 0x64, (byte) 0xA4,
            (byte) 0x6C, (byte) 0xAC, (byte) 0xAD, (byte) 0x6D, (byte) 0xAF, (byte) 0x6F, (byte) 0x6E,
            (byte) 0xAE, (byte) 0xAA, (byte) 0x6A, (byte) 0x6B, (byte) 0xAB, (byte) 0x69, (byte) 0xA9,
            (byte) 0xA8, (byte) 0x68, (byte) 0x78, (byte) 0xB8, (byte) 0xB9, (byte) 0x79, (byte) 0xBB,
            (byte) 0x7B, (byte) 0x7A, (byte) 0xBA, (byte) 0xBE, (byte) 0x7E, (byte) 0x7F, (byte) 0xBF,
            (byte) 0x7D, (byte) 0xBD, (byte) 0xBC, (byte) 0x7C, (byte) 0xB4, (byte) 0x74, (byte) 0x75,
            (byte) 0xB5, (byte) 0x77, (byte) 0xB7, (byte) 0xB6, (byte) 0x76, (byte) 0x72, (byte) 0xB2,
            (byte) 0xB3, (byte) 0x73, (byte) 0xB1, (byte) 0x71, (byte) 0x70, (byte) 0xB0, (byte) 0x50,
            (byte) 0x90, (byte) 0x91, (byte) 0x51, (byte) 0x93, (byte) 0x53, (byte) 0x52, (byte) 0x92,
            (byte) 0x96, (byte) 0x56, (byte) 0x57, (byte) 0x97, (byte) 0x55, (byte) 0x95, (byte) 0x94,
            (byte) 0x54, (byte) 0x9C, (byte) 0x5C, (byte) 0x5D, (byte) 0x9D, (byte) 0x5F, (byte) 0x9F,
            (byte) 0x9E, (byte) 0x5E, (byte) 0x5A, (byte) 0x9A, (byte) 0x9B, (byte) 0x5B, (byte) 0x99,
            (byte) 0x59, (byte) 0x58, (byte) 0x98, (byte) 0x88, (byte) 0x48, (byte) 0x49, (byte) 0x89,
            (byte) 0x4B, (byte) 0x8B, (byte) 0x8A, (byte) 0x4A, (byte) 0x4E, (byte) 0x8E, (byte) 0x8F,
            (byte) 0x4F, (byte) 0x8D, (byte) 0x4D, (byte) 0x4C, (byte) 0x8C, (byte) 0x44, (byte) 0x84,
            (byte) 0x85, (byte) 0x45, (byte) 0x87, (byte) 0x47, (byte) 0x46, (byte) 0x86, (byte) 0x82,
            (byte) 0x42, (byte) 0x43, (byte) 0x83, (byte) 0x41, (byte) 0x81, (byte) 0x80, (byte) 0x40 };

    /**
     * 計(jì)算CRC16校驗(yàn)
     *
     * @param data
     *            需要計(jì)算的數(shù)組
     * @return CRC16校驗(yàn)值
     */
    public static int compute(byte[] data) {
        return compute(data, 0, data.length);
    }

    /**
     * 校驗(yàn)byte數(shù)據(jù)是否是CRC16數(shù)據(jù)
     * @return 是否成功
     */
    public static boolean checkCRC16(byte[] data) {
        int size = data.length;
        if (size <= 2) {
            return false;
        }
        byte[] oldCheckArray = new byte[]{ data[size - 2], data[size - 1]};
        // 將數(shù)據(jù)拆分成三分
        byte[] bytes = new byte[size - 2];
        System.arraycopy(data, 0, bytes, 0, size - 2);
        // 計(jì)算CRC校驗(yàn)碼
        int crc = compute(bytes);
        ByteArrayWriter request = new ByteArrayWriter();
        request.writeInt16Reversal(crc);
        byte[] checkArray = request.toByteArray();
        return Arrays.equals(oldCheckArray, checkArray);
    }

    /**
     * 計(jì)算CRC16校驗(yàn)
     *
     * @param data
     *            需要計(jì)算的數(shù)組
     * @param offset
     *            起始位置
     * @param len
     *            長(zhǎng)度
     * @return CRC16校驗(yàn)值
     */
    public static int compute(byte[] data, int offset, int len) {
        return compute(data, offset, len, 0xffff);
    }

    /**
     * 計(jì)算CRC16校驗(yàn)
     *
     * @param data
     *            需要計(jì)算的數(shù)組
     * @param offset
     *            起始位置
     * @param len
     *            長(zhǎng)度
     * @param preval
     *            之前的校驗(yàn)值
     * @return CRC16校驗(yàn)值
     */
    public static int compute(byte[] data, int offset, int len, int preval) {
        int ucCRCHi = (preval & 0xff00) >> 8;
        int ucCRCLo = preval & 0x00ff;
        int iIndex;
        for (int i = 0; i < len; ++i) {
            iIndex = (ucCRCLo ^ data[offset + i]) & 0x00ff;
            ucCRCLo = ucCRCHi ^ crc16_tab_h[iIndex];
            ucCRCHi = crc16_tab_l[iIndex];
        }
        int result=((ucCRCHi & 0x00ff) << 8) | (ucCRCLo & 0x00ff) & 0xffff;
        return result;
    }
}

2. ByteUtil

package com.jujiang.fyc.myttftwo.utils.modbus;

public class ByteUtil {
    public static String toHexString(byte[] input, String separator) {
        if (input==null) return null;

        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < input.length; i++) {
            if (separator != null && sb.length() > 0) {
                sb.append(separator);
            }
            String str = Integer.toHexString(input[i] & 0xff);
            if (str.length() == 1) str = "0" + str;
            sb.append(str);
        }
        return sb.toString();
    }

    public static String toHexString(byte[] input) {
        return toHexString(input, " ");
    }

    public static byte[] fromInt32(int input){
        byte[] result=new byte[4];
        result[3]=(byte)(input >> 24 & 0xFF);
        result[2]=(byte)(input >> 16 & 0xFF);
        result[1]=(byte)(input >> 8 & 0xFF);
        result[0]=(byte)(input & 0xFF);
        return result;
    }

    public static byte[] fromInt16(int input){
        byte[] result=new byte[2];
        result[0]=(byte)(input >> 8 & 0xFF);
        result[1]=(byte)(input & 0xFF);
        return result;
    }

    public static byte[] fromInt16Reversal(int input){
        byte[] result=new byte[2];
        result[1]=(byte)(input>>8&0xFF);
        result[0]=(byte)(input&0xFF);
        return result;
    }
}

3. ModbusError

package com.jujiang.fyc.myttftwo.utils.modbus;

import android.text.TextUtils;

public class ModbusError extends Exception {
    private int code;

    public ModbusError(int code, String message) {
        super(!TextUtils.isEmpty(message) ? message : "Modbus Error: Exception code = " + code);
        this.code = code;
    }

    public ModbusError(int code) {
        this(code, null);
    }

    public ModbusError(ModbusErrorType type, String message) {
        super(type.name() + ": " + message);
    }

    public ModbusError(String message) {
        super(message);
    }

    public int getCode() {
        return this.code;
    }
}

4. ModbusErrorType

package com.jujiang.fyc.myttftwo.utils.modbus;

/**
 * 常見(jiàn)的Modbus通訊錯(cuò)誤
 */
public enum ModbusErrorType {
    ModbusError,
    ModbusFunctionNotSupportedError,
    ModbusDuplicatedKeyError,
    ModbusMissingKeyError,
    ModbusInvalidBlockError,
    ModbusInvalidArgumentError,
    ModbusOverlapBlockError,
    ModbusOutOfBlockError,
    ModbusInvalidResponseError,
    ModbusInvalidRequestError,
    ModbusTimeoutError
}

5. ModbusFunction

package com.jujiang.fyc.myttftwo.utils.modbus;

/**
 * 功能碼（十進(jìn)制顯示）
 */
public class ModbusFunction {

    //讀線圈寄存器
    public static final int READ_COILS = 1;

    //讀離散輸入寄存器
    public static final int READ_DISCRETE_INPUTS = 2;

    //讀保持寄存器
    public static final int READ_HOLDING_REGISTERS = 3;

    //讀輸入寄存器
    public static final int READ_INPUT_REGISTERS = 4;

    //寫單個(gè)線圈寄存器
    public static final int WRITE_SINGLE_COIL = 5;

    //寫單個(gè)保持寄存器
    public static final int WRITE_SINGLE_REGISTER = 6;

    //寫入多個(gè)線圈寄存器
    public static final int WRITE_COILS = 15;

    //寫入多個(gè)保持寄存器
    public static final int WRITE_HOLDING_REGISTERS = 16;
}

6. ModbusRtuMaster

package com.jujiang.fyc.myttftwo.utils.modbus;

// 提供協(xié)議部分功能
public class ModbusRtuMaster {
    /**
     * 組裝Modbus RTU消息幀
     *
     * @param slave            從站地址號(hào)
     * @param function_code    功能碼
     * @param starting_address 讀取寄存器起始地址 / 寫入寄存器地址 / 寫入寄存器起始地址
     * @param quantity_of_x    讀取寄存器個(gè)數(shù) / 寫入寄存器個(gè)數(shù)
     * @param output_value     需要寫入單個(gè)寄存器的數(shù)值
     * @param output_values    需要寫入多個(gè)寄存器的數(shù)組
     * @return 將整個(gè)消息幀轉(zhuǎn)成byte[]
     * @throws ModbusError Modbus錯(cuò)誤
     */
    synchronized byte[] execute(int slave, int function_code, int starting_address, int quantity_of_x,
                                        int output_value, int[] output_values) throws ModbusError {
        //檢查參數(shù)是否符合協(xié)議規(guī)定
        if (slave < 0 || slave > 0xff) {
            throw new ModbusError(ModbusErrorType.ModbusInvalidArgumentError, "Invalid slave " + slave);
        }
        if (starting_address < 0 || starting_address > 0xffff) {
            throw new ModbusError(ModbusErrorType.ModbusInvalidArgumentError, "Invalid starting_address " + starting_address);
        }
        if (quantity_of_x < 1 || quantity_of_x > 0xff) {
            throw new ModbusError(ModbusErrorType.ModbusInvalidArgumentError, "Invalid quantity_of_x " + quantity_of_x);
        }

        // 構(gòu)造request
        ByteArrayWriter request = new ByteArrayWriter();
        //寫入從站地址號(hào)
        request.writeInt8(slave);
        //根據(jù)功能碼組裝數(shù)據(jù)區(qū)
        //如果為讀取寄存器指令
        if (function_code == ModbusFunction.READ_COILS || function_code == ModbusFunction.READ_DISCRETE_INPUTS
                || function_code == ModbusFunction.READ_INPUT_REGISTERS || function_code == ModbusFunction.READ_HOLDING_REGISTERS) {
            request.writeInt8(function_code);
            request.writeInt16(starting_address);
            request.writeInt16(quantity_of_x);

        } else if (function_code == ModbusFunction.WRITE_SINGLE_COIL || function_code == ModbusFunction.WRITE_SINGLE_REGISTER) {//寫單個(gè)寄存器指令
            if (function_code == ModbusFunction.WRITE_SINGLE_COIL)
                if (output_value != 0) output_value = 0xff00;//如果為線圈寄存器（寫1時(shí)為 FF 00,寫0時(shí)為00 00）
            request.writeInt8(function_code);
            request.writeInt16(starting_address);
            request.writeInt16(output_value);

        } else if (function_code == ModbusFunction.WRITE_COILS) {//寫多個(gè)線圈寄存器
            request.writeInt8(function_code);
            request.writeInt16(starting_address);
            request.writeInt16(quantity_of_x);

            //計(jì)算寫入字節(jié)數(shù)
            int writeByteCount = (quantity_of_x / 8) + 1;/// 滿足關(guān)系-> (w /8) + 1
            //寫入數(shù)量 == 8 ,則寫入字節(jié)數(shù)為1
            if (quantity_of_x % 8 == 0) {
                writeByteCount -= 1;
            }
            request.writeInt8(writeByteCount);

            int index = 0;
            //如果寫入數(shù)據(jù)數(shù)量 > 8 ，則需要拆分開(kāi)來(lái)
            int start = 0;//數(shù)組開(kāi)始位置
            int end = 7;//數(shù)組結(jié)束位置
            int[] splitData = new int[8];
            //循環(huán)寫入拆分?jǐn)?shù)組，直到剩下最后一組 元素個(gè)數(shù) <= 8 的數(shù)據(jù)
            while (writeByteCount > 1) {
                writeByteCount--;
                int sIndex = 0;
                for (index = start; index <= end; index++) {
                    splitData[sIndex++] = output_values[index];
                }
                //數(shù)據(jù)反轉(zhuǎn) 對(duì)于是否要反轉(zhuǎn)要看你傳過(guò)來(lái)的數(shù)據(jù)，如果高低位順序正確則不用反轉(zhuǎn)
                splitData = reverseArr(splitData);
                //寫入拆分?jǐn)?shù)組
                request.writeInt8(toDecimal(splitData));
                start = index;
                end += 8;
            }
            //寫入最后剩下的數(shù)據(jù)
            int last = quantity_of_x - index;
            int[] tData = new int[last];
            System.arraycopy(output_values, index, tData, 0, last);
            //數(shù)據(jù)反轉(zhuǎn) 對(duì)于是否要反轉(zhuǎn)要看你傳過(guò)來(lái)的數(shù)據(jù)，如果高低位順序正確則不用反轉(zhuǎn)
            tData = reverseArr(tData);
            request.writeInt8(toDecimal(tData));
        } else if (function_code == ModbusFunction.WRITE_HOLDING_REGISTERS) {//寫多個(gè)保持寄存器
            request.writeInt8(function_code);
            request.writeInt16(starting_address);
            request.writeInt16(quantity_of_x);
            request.writeInt8(2 * quantity_of_x);
            //寫入數(shù)據(jù)
            for (int v : output_values) {
                request.writeInt16(v);
            }
        } else {
            throw new ModbusError(ModbusErrorType.ModbusFunctionNotSupportedError, "Not support function " + function_code);
        }
        byte[] bytes = request.toByteArray();
        //計(jì)算CRC校驗(yàn)碼
        int crc = CRC16.compute(bytes);
        request.writeInt16Reversal(crc);
        bytes = request.toByteArray();
        return bytes;
    }

    //將數(shù)組反轉(zhuǎn)
    private int[] reverseArr(int[] arr) {
        int[] tem = new int[arr.length];
        for (int i = 0; i < arr.length; i++) {
            tem[i] = arr[arr.length - 1 - i];
        }
        return tem;
    }

    //將int[1,0,0,1,1,0]數(shù)組轉(zhuǎn)換為十進(jìn)制數(shù)據(jù)
    private int toDecimal(int[] data) {
        int result = 0;
        if (data != null) {
            StringBuilder sData = new StringBuilder();
            for (int d : data) {
                sData.append(d);
            }
            try {
                result = Integer.parseInt(sData.toString(), 2);
            } catch (NumberFormatException e) {
                result = -1;
            }

        }
        return result;
    }
}

7. ByteArrayWriter

package com.jujiang.fyc.myttftwo.utils.modbus;

import java.io.ByteArrayOutputStream;

public class ByteArrayWriter extends ByteArrayOutputStream {
    public ByteArrayWriter() {
        super();
    }

    public void writeInt8(byte b)
    {
        this.write(b);
    }

    public void writeInt8(int b)
    {
        this.write((byte)b);
    }

    public void writeInt16(int n) {
        byte[] bytes = ByteUtil.fromInt16(n);
        this.write(bytes, 0, bytes.length);
    }

    public void writeInt16Reversal(int n){
        byte[] bytes=ByteUtil.fromInt16Reversal(n);
        this.write(bytes,0,bytes.length);
    }

    public void writeInt32(int n) {
        byte[] bytes = ByteUtil.fromInt32(n);
        this.write(bytes, 0, bytes.length);
    }

    public void writeBytes(byte[] bs,int len){
        this.write(bs,0,len);
    }
}

8. ModbusRtuSerialPortUtil

package com.jujiang.fyc.myttftwo.utils.modbus

import android_serialport_api.SerialPort
import com.android.jws.JwsManager
import com.android.jws.JwsSerialPort
import com.jujiang.fyc.myttftwo.utils.LogUtils
import java.io.ByteArrayOutputStream
import java.io.File
import java.io.IOException
import java.io.InputStream
import java.io.OutputStream

/**
 * 幫助Modbus 發(fā)送或接受數(shù)據(jù)
 */
class ModbusRtuSerialPortUtil {

    private var jwp: SerialPort? = null
    private var inputStream: InputStream? = null
    private var outputStream: OutputStream? = null

    fun open(device: String, baud: Int, dataBits: Int, parity: Int, stopBit: Int) {
        try {
            // 普通串口通訊
//            jwp = SerialPort(File(device), rate, 0)
            // 設(shè)置驗(yàn)證位等參數(shù)
            jwp = SerialPort(File(device), baud, parity, dataBits, stopBit)
            inputStream = jwp!!.inputStream
            outputStream = jwp!!.outputStream
        } catch (e: IOException) {
            e.printStackTrace()
        }
    }

    // 發(fā)送數(shù)據(jù)
    fun send(bytes: ByteArray, millisecond: Long, block: (ByteArray, ByteArray) -> Unit) {
        try {
            LogUtils.e("bytes = ${bytes.map { String.format("%02x", *arrayOf<Any>(it)) }}")
            outputStream?.apply {
                write(bytes)
                flush()
            }
            Thread.sleep(millisecond)
            // 寫入數(shù)據(jù)
            val size = inputStream!!.available()
            val byteArray = ByteArray(size)
            inputStream!!.read(byteArray)
            block(bytes, byteArray)
        } catch (e: IOException) {
            e.printStackTrace()
        }
    }
}

9. ModbusRtuMasterHelp

package com.jujiang.fyc.myttftwo.utils.modbus

import kotlinx.coroutines.suspendCancellableCoroutine
import kotlin.coroutines.resume

/**
 * 實(shí)際調(diào)用類
 */
class ModbusRtuMasterHelp(private val serialHelper: ModbusRtuSerialPortUtil) {
    private val modbusRtu: ModbusRtuMaster = ModbusRtuMaster()

    /**
     * 讀多個(gè)線圈寄存器
     * @param slave 從站地址
     * @param startAddress 起始地址
     * @param numberOfPoints 讀取線圈寄存器個(gè)數(shù)
     * @throws ModbusError Modbus錯(cuò)誤
     */
    fun readCoils(
        slave: Int,
        startAddress: Int,
        numberOfPoints: Int,
        millisecond: Long = 50,
        block: (ByteArray, ByteArray) -> Unit
    ) {
        val sendBytes = modbusRtu.execute(
            slave,
            ModbusFunction.READ_COILS,
            startAddress,
            numberOfPoints,
            0,
            null
        )
        this.serialHelper.send(sendBytes, millisecond, block)
    }

    //讀單個(gè)線圈寄存器
    fun readCoils(
        slave: Int,
        startAddress: Int,
        millisecond: Long = 50,
        block: (ByteArray, ByteArray) -> Unit
    ) {
        readCoils(slave, startAddress, 1, millisecond, block)
    }

    // 異步讀取并返回結(jié)果
    suspend fun readCoilsAsync(slave: Int,
                               startAddress: Int,
                               millisecond: Long = 50): Pair<ByteArray, ByteArray> {
        return suspendCancellableCoroutine { continuation ->
            readCoils(slave, startAddress, millisecond) { old, new ->
                continuation.resume(Pair(old, new))
            }
        }
    }

    /**
     * 寫單個(gè)線圈寄存器
     * @param slave 從站地址
     * @param address 寫入寄存器地址
     * @param value 寫入值（true/false)
     * @throws ModbusError Modbus錯(cuò)誤
     */
    fun writeSingleCoil(
        slave: Int, address: Int, value: Boolean, millisecond: Long = 50,
        block: (ByteArray, ByteArray) -> Unit
    ) {
        val sendBytes = modbusRtu.execute(
            slave,
            ModbusFunction.WRITE_SINGLE_COIL,
            address,
            1,
            if (value) 1 else 0,
            null
        )
        this.serialHelper.send(sendBytes, millisecond, block)
    }

    // 異步寫并返回結(jié)果
    suspend fun writeSingleCoilAsync(slave: Int, address: Int, value: Boolean, millisecond: Long = 50): Pair<ByteArray, ByteArray> {
        return suspendCancellableCoroutine { continuation ->
            writeSingleCoil(slave, address, value, millisecond) { old, new ->
                continuation.resume(Pair(old, new))
            }
        }
    }
}

三、使用

class MainActivity : BaseBindingActivity<ActivityMainBinding>({
    ActivityMainBinding.inflate(it)
}) {
    private val modbusRtuSerialPortUtil by lazy { ModbusRtuSerialPortUtil() }
    private val modbusRtuSerialPort by lazy { ModbusRtuMasterHelp(modbusRtuSerialPortUtil) }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        // 連接串口, 一定要保證串口是能正常的讀寫, 否則會(huì)導(dǎo)致后續(xù)讀寫操作失效, 如果提示無(wú)權(quán)限, 只能讓嵌入式工程師
        // 使用單片機(jī)來(lái)做通訊, Android以普通串口讀取方式來(lái)使用, 如果能正常讀取成功, 可以采用實(shí)例方法
        modbusRtuSerialPortUtil.open("/dev/ttyS3", 19200, 8, 2, 1)
        // 同步讀取線圈, 參數(shù)1: 地址; 參數(shù)2: 線圈地址; 返回參數(shù)1: 表示發(fā)送時(shí)的byte數(shù)組; 參數(shù)2: 表示設(shè)備回發(fā)的數(shù)據(jù)數(shù)組
        modbusRtuSerialPort.readCoils(0x01, 0x0A) { oldAray, byteArray -> }
        // 異步讀取在協(xié)程中操作即可
        lifecycleScope.launch(Dispatchers.IO) {
            // 在協(xié)程中可以讀取的操作方式有很多種, 這里只演示一種, 如果只是需要讀一個(gè)那可以不需要使用 async 包裹
            async {
                val (oldArray, byteArray) = modbusRtuSerialPort.readCoilsAsync(0x01, 0x0A)
                // CRC16.checkCRC16 用于校驗(yàn)返回?cái)?shù)據(jù)的后兩位是否符合協(xié)議驗(yàn)證, 如果不符合則需要聯(lián)系設(shè)備商修改
                if (CRC16.checkCRC16(byteArray)) {
                }
            }.await()
        }
        // 同步寫數(shù)據(jù), 參數(shù)1: 地址; 參數(shù)2: 線圈地址; 參數(shù)3: 需要寫入的內(nèi)容,線圈操作類似于按鈕,所以只需要true/false即可;
        // 返回參數(shù)1: 表示發(fā)送時(shí)的byte數(shù)組; 參數(shù)2: 表示設(shè)備回發(fā)的數(shù)據(jù)數(shù)組
        // 異步寫入這里就不在演示了, 目前沒(méi)涉及到需要異步寫入的需求
        modbusRtuSerialPort.writeSingleCoil(0x01, 0x00, true) { oldAray, byteArray ->
            // 校驗(yàn)兩次數(shù)據(jù)是否相等,不相等即表示操作失敗
            if (oldAray.contentEquals(byteArray)) {
            }
        }
    }
}

總結(jié)

本篇文章主要記錄Android使用modbus協(xié)議, 其中遇到了按照本篇文章中的方式去讀取后會(huì)提示無(wú)權(quán)限的情況或?qū)懭霐?shù)據(jù)無(wú)返回, 對(duì)該情況的推測(cè)是串口的打開(kāi)是成功的但是沒(méi)有寫入數(shù)據(jù)到設(shè)備中, 因?yàn)槿绻跊](méi)打開(kāi)或打開(kāi)失敗會(huì)拋出異常, 通過(guò)協(xié)調(diào)之后得到的結(jié)論是設(shè)備并不支持Android主板, 解決方案是讓嵌入式工程師使用單片機(jī)做一個(gè)中間層，單片機(jī)只負(fù)責(zé)與設(shè)備連接與數(shù)據(jù)寫入操作, Android這邊按照modbus協(xié)議發(fā)送數(shù)據(jù)給單片機(jī), 單片機(jī)將數(shù)據(jù)發(fā)送給設(shè)備, 設(shè)備回發(fā)數(shù)據(jù)后單片機(jī)讀取數(shù)據(jù)后寫入數(shù)據(jù), Android讀取數(shù)據(jù)拿到實(shí)際結(jié)果, 該方案可以解決實(shí)際問(wèn)題。文章來(lái)源地址http://www.zghlxwxcb.cn/news/detail-621648.html

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