Android节点读写实现

在工作中，我们会对一些节点进行读写操作。比如控制闪光灯，指示灯;降噪芯片开关或其低功耗开关，因为项目中常用到，在此记录，备忘～

直接上代码，想用直接拿去

一 监听某个节点的写入值的反馈

有些节点写入是可以监听到写入结果的，比如降噪芯片低功耗节点写入后可以监听其写入结果，代码如下

/**
 * 读取操作低功耗的开启/关闭结果
 */
private void readOpenLowPowerCOnsumptionResult() {
        Log.e(TAG, "readOpenLowPowerCOnsumptionResult init");

            new Thread(() -> {
                try {
                    File deviceFile = new File("/dev/ttyS0");
                    if (!deviceFile.exists()) {
                        Log.e(TAG,"Device file not found: " + "/dev/ttyS0");
                        return;
                    }

                    FileInputStream fis = new FileInputStream(deviceFile);
                    BufferedReader reader = new BufferedReader(new InputStreamReader(fis));
                    Log.d(TAG, "Reading from " + "/dev/ttyS0" + "...");
                    String line;
                    while ((line = reader.readLine()) != null) {
                        Log.d(TAG,"Log: " + line);
                        if ("OK: low_pw 1".equals(line)) {
                            Log.e(TAG, "auxstatus open low_pw success");
                            // isWaitingRead =false;
                        

                        }else if ("OK: low_pw 0".equals(line)) {
                            Log.e(TAG, "auxstatus close low_pw success");
                            // isWaitingRead =false;
                           
                        }else {
                            Log.e(TAG, "readOpenAudResult result :" + line);

                        }
                    }
                    Log.d(TAG, "Reading from " + "/dev/ttyS0" + "---");
                    reader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                    Log.e(TAG, "Error reading from /dev/ttyS0");
                }
            }).start();

    }

二 写入节点

2.1

        /**
 * 开启降噪低功耗模式
 * @param  isOpen true：开启低功耗;false 关闭低功耗
 * @return        [description]
 */
private synchronized boolean openAudLowPower(boolean isOpen) {
        Log.d(TAG, "openAudLowPower init----1 isOpen:" + isOpen);
        java.lang.Process process = null;
        DataOutputStream os = null;
        try {
            String[] command = {"sh"};
            process = Runtime.getRuntime().exec(command);
            os = new DataOutputStream(process.getOutputStream());
            os.writeBytes( "stty -F /dev/ttyS0 -echo\n");
            os.writeBytes( "stty -F /dev/ttyS0 ispeed 115200 ospeed 115200 cs8\n");
            if (isOpen) {
                os.writeBytes("printf 'low_pw 1' > /dev/ttyS0\n");
            }else {
                os.writeBytes("printf 'low_pw 0' > /dev/ttyS0\n");
            }
            os.writeBytes("exit\n");
            os.flush();
            int result = process.waitFor();
            Log.d(TAG, "openAudch result : " + result);

        } catch (Exception e) {
            Log.d(TAG, "openAudLowPower exception msg: " + e.getMessage());
            Log.e(TAG, "openAudLowPower , send error");
            e.printStackTrace();
            return false;
        } finally {
            try {
                if (os != null) {
                    os.close();
                }
                process.destroy();
            } catch (Exception e) {
                Log.e(TAG, "send error");
                return false;
            }
            Log.e(TAG, "openAudLowPower finally end");
        }
        return true;
    }

2.2还有使用echo 实现写入节点，代码如下

 public boolean openEncLvl() {
        if (DEBUG_INPUT) {
            Slog.d(TAG, "openEncLvl init---- ");
        }
        java.lang.Process process = null;
        DataOutputStream os = null;
        try {
            process = Runtime.getRuntime().exec("sh");
            os = new DataOutputStream(process.getOutputStream());
            os.writeBytes( "stty -F /dev/ttyS0 -echo\n");
            os.writeBytes( "stty -F /dev/ttyS0 ispeed 115200 cs8\n");
            os.writeBytes( "echo enc_lvl 1 > /dev/ttyS0\n");
            os.writeBytes("exit\n");
            os.flush();
            process.waitFor();
        } catch (Exception e) {
            if (DEBUG_INPUT) {
                 Slog.d(TAG, "openEncLvl exception msg: " + e.getMessage());
            }
            Log.e(TAG, "openEncLvl , 发送失败。");
            e.printStackTrace();
            return false;
        } finally {
            try {
                if (os != null) {
                    os.close();
                }
                process.destroy();
            } catch (Exception e) {
                Log.e(TAG, "发送失败");
                return false;
            }
            if (DEBUG_INPUT) {
                 Slog.d(TAG, "openEncLvl finally end");
            }
        }
        return true;
    }

2.1和2.2 实现的区别就是写入值的时候

2.1如下实现：

os.writeBytes("printf 'low_pw 1' > /dev/ttyS0\n");

2.2如下实现：

os.writeBytes( "echo enc_lvl 1 > /dev/ttyS0\n");

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若使用直接拿去，可运行！

 大家新年快乐～