diff --git a/lib/serialport-comms.js b/lib/serialport-comms.js
index 9375541..cc41103 100644
--- a/lib/serialport-comms.js
+++ b/lib/serialport-comms.js
@@ -17,7 +17,7 @@ serialCom.prototype.setUpInterface = function(callback) {
   var self = this;
   this.device.open(function() {
     self.device.on('data', function(data) {
-      self.debug('data', data)
+      self.debug('data', data);
       self.responses.push(data);
     });
     self.sync(function(error) {
@@ -35,7 +35,7 @@ serialCom.prototype.close = function() {
 serialCom.prototype.write = function(data, callback) {
   var self = this;
   // this will need to swap between 200 and 1000 depending on the command
-  var drainDelay = 200;
+  var drainDelay = 800;
 
   this.device.write(data, function(error, results) {
     if (error) { return callback(new Error(error)); }
diff --git a/package.json b/package.json
index 7142270..16bde3f 100644
--- a/package.json
+++ b/package.json
@@ -35,6 +35,7 @@
     "proxyquire": "^1.6.0",
     "sinon": "^1.15.4",
     "tap-spec": "^4.0.2",
-    "tape": "^4.0.1"
+    "tape": "^4.0.1",
+    "virtual-serialport": "^0.1.1"
   }
 }
diff --git a/tests/avrgirl-stk500v2.spec.js b/tests/avrgirl-stk500v2.spec.js
index e5731dd..a97a6ab 100644
--- a/tests/avrgirl-stk500v2.spec.js
+++ b/tests/avrgirl-stk500v2.spec.js
@@ -488,4 +488,5 @@ test('[ AVRGIRL-STK500V2 ] ::getChipSignature', function (t) {
 });
 
 require('./libusb-comms.spec');
+require('./serialport-comms.spec');
 
diff --git a/tests/serialport-comms.spec.js b/tests/serialport-comms.spec.js
new file mode 100644
index 0000000..9d08c3a
--- /dev/null
+++ b/tests/serialport-comms.spec.js
@@ -0,0 +1,112 @@
+// harness
+var test = require('tape');
+// test helpers
+var sinon = require('sinon');
+var bufferEqual = require('buffer-equal');
+var vserial = require('virtual-serialport');
+//var vserialport = vserial.SerialPort;
+
+// module to test
+var serialcom = require('../lib/serialport-comms');
+
+var device = new vserial('/dev/cu.usbmodem1411', {
+  baudrate: 115200
+}, false);
+// stubby stub
+device.open = function(callback) {
+  if (callback) {
+    return callback(null);
+  }
+  return;
+};
+device.close = function(callback) {
+  if (callback) {
+    return callback(null);
+  }
+  return;
+};
+device.drain = function(callback) {
+  if (callback) {
+    return callback(null);
+  }
+  return;
+};
+
+test('[ SERIALPORT-COMMS ] method presence', function (t) {
+  var b = new serialcom(device);
+  function isFn(name) {
+    return typeof b[name] === 'function';
+  };
+  var methods = [
+    'open',
+    'close',
+    'setUpInterface',
+    'read',
+    'write'
+  ];
+  for (var i = 0; i < methods.length; i += 1) {
+    t.ok(isFn(methods[i]), methods[i]);
+    if (i === (methods.length - 1)) {
+      t.end();
+    }
+  }
+});
+
+test('[ SERIALPORT-COMMS ] ::open', function (t) {
+  var b = new serialcom(device);
+
+  var spy = sinon.spy(device, 'open');
+
+  t.plan(1);
+  b.open();
+  t.ok(spy.calledOnce, 'called device.open');
+});
+
+test('[ SERIALPORT-COMMS ] ::close', function (t) {
+  var b = new serialcom(device);
+  var spy = sinon.spy(device, 'close');
+
+  t.plan(1);
+  b.close();
+  t.ok(spy.calledOnce, 'called device.close');
+});
+
+test('[ SERIALPORT-COMMS ] ::write', function (t) {
+  var b = new serialcom(device);
+  var buf = new Buffer([0x01]);
+
+  t.plan(1);
+
+  var spy = sinon.spy(device, 'write');
+  b.write(buf);
+  var cond = (spy.calledOnce && spy.args[0][0] && bufferEqual(spy.args[0][0], buf));
+  t.ok(cond, 'called write method on correct endpoint with correct buffer arg');
+});
+
+test('[ SERIALPORT-COMMS ] ::read', function (t) {
+  var b = new serialcom(device);
+  b.responses.push(new Buffer(8));
+  var spy = sinon.spy(b, 'read');
+  t.plan(3);
+
+  b.read(8, function(error, data){
+    t.error(error, 'no error');
+    t.ok(spy.calledWith(8), 'called read method on correct endpoint with arg 8');
+    t.equals(data.length, 8, 'got data');
+  });
+});
+
+test('[ SERIALPORT-COMMS ] ::setUpInterface', function (t) {
+  var b = new serialcom(device);
+  var stub = sinon.stub(b, 'sync', function(callback) {
+    return callback(null);
+  });
+
+  t.plan(3);
+
+  b.setUpInterface(function (error) {
+    t.pass('interface set up and called back');
+    t.error(error, 'no error');
+    t.ok(stub.calledOnce, 'sync method called');
+  });
+});