Bonescript: write to serial port fails although port is open - serial-port

Question

Here is bonescript for testing serial connection in BeagleBone black by exchanging and incrementing characters
var b = require('bonescript');
var port1='/dev/ttyO1';
var port2='/dev/ttyO2';
var options={
baudrate: 9600,
parity: 'even',
parser: b.serialParsers.readline("\n")
};
console.log(b.serialOpen(port1, options, onSerial1));// open port 1
console.log(b.serialOpen(port2, options, onSerial2));//open port 2
b.serialWrite(port1,'A');//start letter bouncing
function onSerial1(x){
if (x.event == 'data') {
console.log(x.data);
var char =x.data;//get letter
if(char=='Z')
char='A';// reset or incremet
else
char++;
b.serialWrite(port2,char);
}
}
function onSerial2(x){
if (x.event == 'data') {
console.log(x.data);
var char =x.data;
if(char=='Z')
char='A';
else
char+=1;
b.serialWrite(port1,char);
}
}
Here is output in cloud9:
^
debugger listening on port 15454
true
true
events.js:72
throw er; // Unhandled 'error' event
^
Error: Serialport not open.
at SerialPort.write (/usr/local/lib/node_modules/bonescript/node_modules/serialport/serialport.js:246:17)
at Object.exports.wrapCall.newFunction [as serialWrite] (/usr/local/lib/node_modules/bonescript/my.js:198:41)
at Object.<anonymous> (/var/lib/cloud9/serial/myserial.js:12:3)
at Module._compile (module.js:456:26)
at Object.Module._extensions..js (module.js:474:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.runMain [as _onTimeout] (module.js:497:10)
at Timer.listOnTimeout [as ontimeout] (timers.js:110:15)
As you may see serialOpen successfully opens the ports (returns true) but initial write fails. I can.t think of a reason.

Answer 1

It is possible that port2 is not yet opened when port1 sends it the letter A at the first time.
Try to make some delay between the 2 lines
console.log(b.serialOpen(port2, options, onSerial2));//open port 2
b.serialWrite(port1,'A');//start letter bouncing
You may try using setTimeOut(b.serialWrite(port1,'A'), 2000);
or write on port1 when the event at port2 is opened.