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我试图打开串口2在我的猎兔犬骨，使用下面的代码的串行端口时：无法打开文件“的/ dev/ttyO2”试图利用在Beaglebone黑
var b = require('bonescript');
var x = '/dev/ttyO2';
var SerialPort = require("serialport").SerialPort;
var serialPort = new SerialPort('/dev/ttyO2', {
baudrate: 115200,
parser: b.serialParsers.readline("\n")
});
的完整的代码：
var b = require('bonescript');
var x = '/dev/ttyO2';
var SerialPort = require("serialport").SerialPort;
var serialPort = new SerialPort('/dev/ttyO2', {
baudrate: 115200,
parser: b.serialParsers.readline("\n")
});
b.pinMode("P9_17", b.OUTPUT);
var countTry =2;
var i = 0; // to loop over the array
var waiting_interval = 3000; // waiting for every slave to reply
var deli;
var slaves = ["S1", "S2" , "S3", "S4", "S5", "S6"];
var counter=[0 , 0 , 0 , 0 ,0 ,0];
var slave_exists = false;
serialPort.on('open',function onSerialOpen(){
console.log("opened");
serialPort.on('data', function listenToSlaves(data){
i--;
if(data.search("END" + slaves[i]) ==0){
console.log("ENDED");
slave_exists = true;
counter[i]=0;
}
else{
// if(data!="END" + slaves[i]){
if(data.search("END" + slaves[i])!==0){
deli = data.indexOf(":");
var parameter = data.substring(0, deli);
var value = data.substring(deli +1);
console.log("parameter is: " + parameter + " - Value is: " + value);
}
}
if(slave_exists){
counter[i] =0;
}
i++;
});
writeToSlaves();
});
function writeToSlaves(){
//If the previous slave (the slave before the one I am sending to
//in the next step doesnt exist, add the counter or consideer
//it not existing)
if(!slave_exists){
counter[i-1]+=1;
if(counter[i-1]>=countTry){
console.log("--------counter[" + i + "]: " + counter[i]);
// in case that the slave returned no data after trying
//to send him several times
console.log(slaves[i-1] + " doesn't exist");
}
}
//sending to the following slave
b.digitalWrite("P9_17", b.HIGH);
serialPort.write(slaves[i], function(){ slave_exists = false;});
b.digitalWrite("P9_17", b.LOW);
console.log("I wrote to slave: " + i);
if(i<slaves.length - 1) i++;
else i=0;
setTimeout(writeToSlaves, waiting_interval);
}
，但我总是面临着这样的错误：events.js:72 throw er; // Unhandled 'error' event ^ Error: Cannot open /dev/ttyO2 我正在另一个文件中的第一（代码下），在我尝试重新运行以前的代码，它运行完美。我需要这样做，只要我想运行第一个代码！ 从第一次运行的代码是在这里： （我试过独自下面的代码，将其写入串行端口，但犯规收到，在recieption任何情况下）：
var b = require('bonescript');
var rxport = '/dev/ttyO2';
var txport = '/dev/ttyO2';
var options = { baudrate: 115200, parity: 'even', parser: b.serialParsers.readline('\n') };
var teststring = "This is the string I'm sending out as a test";
b.serialOpen(rxport, options, onRxSerial);
function onRxSerial(x) {
console.log('rx.eventrx= ' + x.event);
if(x.err) throw('***FAIL*** ' + JSON.stringify(x));
if(x.event == 'open') {
//readReapeatedly();
b.serialOpen(txport, options, onTxSerial);
}
if(x.event == 'data') {
console.log("I am receiving on rxport");
console.log('rx (' + x.data.length +
') = ' + x.data.toString('ascii'));
}
}
function onTxSerial(x) {
console.log('tx.event = ' + x.event);
if(x.err) throw('***FAIL*** ' + JSON.stringify(x));
if(x.event == 'open') {
writeRepeatedly();
}
if(x.event == 'data') {
// console.log('tx (' + x.data.length +
// ') = ' + x.data.toString('ascii'));
console.log(x.data);
}
}
function printJSON(x) {
console.log(JSON.stringify(x));
}
function writeRepeatedly() {
console.log("write to serial");
b.serialWrite(txport, teststring, onSerialWrite);
console.log("I have sent data");
}
function onSerialWrite(x) {
console.log("Iam in the onSerialWrite function");
if(x.err) console.log('onSerialWrite err = ' + x.err);
if(x.event == 'callback') {setTimeout(writeRepeatedly, 5000);
console.log("HERE");
}
}