add printer func

config.json

@@ -8,5 +8,8 @@
 				"data":"00000002-8f05-4e30-beb0-6fa7ea3dfc3e"
 			}
 		}
+	},
+	"printer": {
+		"serial": "/dev/ttyUSB0"
 	}
 }

gdata-characteristic.js

@@ -1,5 +1,13 @@
 const bleno = require('bleno')
 const config = require('./config.json')
+const escpos = require('escpos')
+const device = escpos.Serial(config.printer.serial)
+const printer = escpos.Printer(device)
+let isOpen = false
+
+device.open(()=>{
+  isOpen = true
+})
 
 var tmp = []
 
@@ -26,7 +34,8 @@ class DataCharacteristic extends bleno.Characteristic {
       console.log(data[0])
     } else if (data.length == 1 && data[0] == 0xff) {
       //console.log(tmp)
-      console.log(new Buffer(tmp).toString())
+      console.log(Buffer.from(tmp).toString())
+      printString(Buffer.from(tmp).toString())
     } else {
       tmp = [...tmp, ...data.slice(2, data.length)]
     }
@@ -37,4 +46,17 @@ class DataCharacteristic extends bleno.Characteristic {
   }
 }
 
+
+function printString(str){
+  if(!isOpen) return 
+  let strs = str.split(/\n/)
+  printer.font('a')
+    .align('ct')
+    .size(1,1)
+  for(let i in strs){
+    printer.text(strs[i])
+  }
+  printer.cut(true, 8)
+}
+
 module.exports = DataCharacteristic

package.json

@@ -5,6 +5,7 @@
   "license": "MIT",
   "dependencies": {
     "bleno": "^0.4.2",
+    "escpos": "^2.4.3",
     "uuid": "^3.1.0"
   }
 }