600字范文 > TinyOS之串口通信TestSerial数据包分析

TinyOS之串口通信TestSerial数据包分析

时间：2020-06-28 05:21:31

1.串口通信样例

本文以tinyos-2.1.1下的TestSerial样例程序为例；

其路径为/opt/tinyos-2.1.1/apps/tests/TestSerial

TestSerialAppC.nc

#include "TestSerial.h"configuration TestSerialAppC {}implementation {components TestSerialC as App, LedsC, MainC;components SerialActiveMessageC as AM;components new TimerMilliC();App.Boot -> MainC.Boot;App.Control -> AM;App.Receive -> AM.Receive[AM_TEST_SERIAL_MSG];App.AMSend -> AM.AMSend[AM_TEST_SERIAL_MSG];App.Leds -> LedsC;App.MilliTimer -> TimerMilliC;App.Packet -> AM;}

TestSerialC.nc

#include "Timer.h"#include "TestSerial.h"module TestSerialC {uses {interface SplitControl as Control;interface Leds;interface Boot;interface Receive;interface AMSend;interface Timer<TMilli> as MilliTimer;interface Packet;}}implementation {message_t packet;bool locked = FALSE;uint16_t counter = 0;event void Boot.booted() {call Control.start();}event void MilliTimer.fired() {counter++;if (locked) {return;}else {test_serial_msg_t* rcm = (test_serial_msg_t*)call Packet.getPayload(&packet, sizeof(test_serial_msg_t));if (rcm == NULL) {return;}if (call Packet.maxPayloadLength() < sizeof(test_serial_msg_t)) {return;}rcm->counter = counter;if (call AMSend.send(AM_BROADCAST_ADDR, &packet, sizeof(test_serial_msg_t)) == SUCCESS) {locked = TRUE;}}}event message_t* Receive.receive(message_t* bufPtr, void* payload, uint8_t len) {if (len != sizeof(test_serial_msg_t)) {return bufPtr;}else {test_serial_msg_t* rcm = (test_serial_msg_t*)payload;if (rcm->counter & 0x1) {call Leds.led0On();}else {call Leds.led0Off();}if (rcm->counter & 0x2) {call Leds.led1On();}else {call Leds.led1Off();}if (rcm->counter & 0x4) {call Leds.led2On();}else {call Leds.led2Off();}return bufPtr;}}event void AMSend.sendDone(message_t* bufPtr, error_t error) {if (&packet == bufPtr) {locked = FALSE;}}event void Control.startDone(error_t err) {if (err == SUCCESS) {call MilliTimer.startPeriodic(1000);}}event void Control.stopDone(error_t err) {}}

TestSerial.h

#ifndef TEST_SERIAL_H#define TEST_SERIAL_Htypedef nx_struct test_serial_msg {nx_uint16_t counter;} test_serial_msg_t;enum {AM_TEST_SERIAL_MSG = 0x89,};#endif

2.编译烧录程序

cd /opt/tinyos-2.1.1/apps/tests/TestSerial //进入目录make telosb install //编译烧录

3.获取节点发送的串口数据

1）Ubuntu下的Listen监听

使用tinyos自带的Listen工具监听节点发送给我们的数据包

命令为：

java net.tinyos.tools.Listen -comm serial@/dev/ttyUSB0:telosb

其结果如下图所示：

2）windows下的串口工具监听

使用windows下的串口工具监听节点发送给我们的数据包

其结果如下图所示：

4.节点数据的简易分析

可以看出节点发送的真实数据包为：

7E 45 00 FF FF 00 00 02 00 89 00 F0 FE DB 7E

这与TinyOS的TEP技术文档中的TEP113中介绍的一致

即可以分解为如下几个部分：

7E 45 00 FF FF 00 00 02 00 89 00 F0 FE DB 7E

F 包头帧 7E 数据包的开头与结尾标志位

P 协议帧 45 代表数据是否需要应答信号，44表示需要应答的节点接收数据，45则表示节点发送的数据。在serial.h头文件中有定义SERIAL_PROTO_PACKET_NOACK = 69。

S 序号帧序号字节，与SerialP.nc有关

其中没有S位的原因见TEP的原文：

SerialP uses SerialFrameComm to send a delimiter between frames, a serial-level type field, the bytes of the packet, and a two-byte frame CRC. For mote-to-host gap detection and link reliability, a sequence number may also be sent (not activated in the default implementation).

D 包类帧 00 包格式的分派字节，与SerialDispatcherC.nc相关，用于串口分发，AM消息默认为0，TOS_SERIAL_ACTIVE_MESSAGE_ID = 0

Payload 负载帧 FF FF 00 00 02 00 89 00 F0 表示的是发送的payload数据段

FF FF dest 目的地地址

00 00 src源地址，T2.0默认不填充该部分，所以为０

02 length就是后面data载荷长度

00 group 在T2.0中注释掉了，不填充，故为０

89 type

注意：7E->7D 5E,7D->7D 5D

CR 校验帧 FE DB 由CRC校验产生的校验位，低位在前，高位在后

F 包尾帧 7E

5.crc校验方法

uint16_t crcByte(uint16_t crc, uint8_t b) {crc = (uint8_t)(crc >> 8) | (crc << 8);crc ^= b;crc ^= (uint8_t)(crc & 0xff) >> 4;crc ^= crc << 12;crc ^= (crc & 0xff) << 5;return crc;}