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我正在扩展 BaseIOIOLooper 以打开 UART 设备并发送消息。我正在使用回读进行测试，我通过一条线路发送一个数据包并在另一条线路上接收该数据包并将其打印出来。因为我不希望 InputStream.read() 方法阻塞，所以我正在处理数据包的形成并在不同的线程中输入。我已将问题缩小到 InputStream.read() 方法，该方法返回 -1（没有读取字节，但没有例外）。这是它在 Looper 线程中的样子：

        @Override
    protected void setup() throws ConnectionLostException, InterruptedException {
        log_.write_log_line(log_header_ + "Beginning IOIO setup.");
        // Initialize IOIO UART pins
        // Input at pin 1, output at pin 2
        try {
            inQueue_ = MinMaxPriorityQueue.orderedBy(new ComparePackets())
                    .maximumSize(QUEUESIZE).create();
            outQueue_ = MinMaxPriorityQueue.orderedBy(new ComparePackets())
                    .maximumSize(QUEUESIZE).create();
            ioio_.waitForConnect();
            uart_ = ioio_.openUart(1, 2, 38400, Uart.Parity.NONE, Uart.StopBits.ONE);
            // Start InputHandler. Takes packets from ELKA on inQueue_
            in_= new InputHandler(inQueue_, uart_.getInputStream());
            in_.start();
            // Start OutputHandler. Takes packets from subprocesses on outQueue_
            out_= new OutputHandler(outQueue_);
            out_.start();
            // Get output stream
            os_=uart_.getOutputStream();
            // Set default target state
            setTargetState(State.TRANSFERRING);
            currInPacket_[0]=1; //Initial value to start transferring
            log_.write_log_line(log_header_ + "IOIO setup complete.\n\t" +
                    "Input pin set to 1\n\tOutput pin set to 2\n\tBaud rate set to 38400\n\t" +
                    "Parity set to even\n\tStop bits set to 1");
        } catch (IncompatibilityException e) {
            log_.write_log_line(log_header_+e.toString());
        } catch (ConnectionLostException e) {
            log_.write_log_line(log_header_+e.toString());
        } catch (Exception e) {
            log_.write_log_line(log_header_+"mystery exception: "+e.toString());
        }
    }

在 InputHandler 线程中：

    @Override
public void run() {
    boolean notRead;
    byte i;
    log_.write_log_line(log_header_+"Beginning InputHandler thread");
    while (!stop) {
        i = 0;
        notRead = true;
        nextInPacket = new byte[BUFFERSIZE];
        readBytes = -1;
        //StringBuilder s=new StringBuilder();
        //TODO re-implement this with signals
        while (i < READATTEMPTS && notRead) {
            try {
                // Make sure to adjust packet size. Done manually here for speed.
                readBytes = is_.read(nextInPacket, 0, BUFFERSIZE);
                /* Debugging
                for (int j=0;j<nextInPacket.length;j++)
                    s.append(Byte.toString(nextInPacket[j]));
                log_.write_log_line(log_header_+s.toString());
                */

                if (readBytes != -1) {
                    notRead = false;
                    nextInPacket= new byte[]{1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0};
                    synchronized (q_) {
                        q_.add(nextInPacket);
                    }
                //log_.write_log_line(log_header_ + "Incoming packet contains valid data.");
                } else i++;
            } catch (IOException e) {
                log_.write_log_line(log_header_ + "mystery exception:\n\t" + e.toString());
            }
        }

        if (i>=READATTEMPTS)
            log_.write_log_line(log_header_+"Too many read attempts from input stream.");

        /*
        try {
            sleep(100);
        } catch (InterruptedException e) {
            log_.write_log_line(log_header_+"fuck");
        }
        */
    }
}

在示波器上，引脚 1 和 2 都读取一个振荡电压，尽管幅度非常高，这是值得关注的。点是不能从 InputHandler 类中的 InputStream 中读取任何内容。有任何想法吗？

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1 回答 1

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从返回的 -1read()应该只在 UART 关闭时发生。闭包可能是显式调用对象或调用对象的close()结果。UartsoftReset()IOIO

Android 日志可能会为您提供一些关于正在发生的事情的线索。

您在示波器上看到的读数很可疑：“非常高的幅度”有多高？您应该只在这些引脚上看到 0V 或 3.3V，或者在引脚由于某种原因未打开（或关闭）的情况下浮动。

于 2015-12-19T02:39:32.880 回答