node.js and bluetooth barcode-scanner -

i struggling quite while solid, long-term connection bluetooth barcode scanner inateck using node.js. process running in background (linux, no input-focus) that's why configured scanner spp device.

the connection working long scanner doesn't automatically switch off save power, after 5 minutes.

my first approach use bluetooth-serial-port package. discovers scanner, reads barcodes when scanner switches off, don't know how re-connect. added interval timer check connection , try connect again if isopen() returns false (which works once). when press button on scanner switches on , can re-connect after view seconds isopen() returns false if connection established, , don't further readings. here code:

var btserial = new (require('bluetooth-serial-port')).bluetoothserialport(); var btinterval = null;  btserial.on('found', function (address, name) {      btserial.findserialportchannel(address, function (channel) {         if (address === '00:06:11:68:15:81') {             btserial.connect(address, channel, function () {                 console.log('connected ' + address);                  btinterval = setinterval(function () {                     if (!btserial.isopen()) {                          btserial.close();                         clearinterval(btinterval);                         console.log('lost connection - try reconnect');                          btserial.inquire();                     }                  }, 5000);              }, function () {                 console.log('cannot connect ' + address);             });         }      }, function () {         console.log('found nothing');     }); });  btserial.on('finished', function () {     console.log('finished'); });  btserial.on('data', function (buffer) {     console.log(buffer.tostring('utf-8')); });   btserial.inquire(); 

the output looks this:

finished connected 00:06:11:68:15:81 found nothing ... scanning works ... lost connection - try reconnect finished connected 00:06:11:68:15:81 ... scanning works ... lost connection - try reconnect finished ... that's - no more scans ... ^c 

an other idea use nodes fs() read directly '/dev/rfcomm0'.

scanner = fs.createreadstream('/dev/rfcomm0', {buffersize: 1});  scanner.on('open', function () {     logger.info('scanner connected'); });  scanner.on('end', function () {     logger.info('end of data stream'); });  scanner.on('close', function () {     logger.info('scanner disconnected'); });  scanner.on('error', function (error) {     logger.error('scanner error'); });  scanner.on('data', function (chunk) {     logger.info(chunk.tostring('ascii', 0, 13));         }     }); }); 

connecting done os automatically when reading device , receive codes via on('data',..). have same problem when scanner switches off after while. receive on('close',..) event reconnecting using fs.createreadstream() again doesn't work more.

maybe of had deal such problem , can give me hint how handle this. appreciate every suggestion.

thanks, max

that's not way wanted go bash script launch node app when scanner available, job:

#!/bin/bash  echo "press ctrl+c stop..."  while :    if hcitool scan | grep -q "00:06:11:68:15:81";      # bt scanner found      node .    fi     sleep 1 done