diff --git a/artiq/gui/moninj.py b/artiq/gui/moninj.py
index 8391b761b..dfc7b1632 100644
--- a/artiq/gui/moninj.py
+++ b/artiq/gui/moninj.py
@@ -2,8 +2,9 @@ import asyncio
 import logging
 import socket
 import struct
+from operator import itemgetter
 
-from quamash import QtGui
+from quamash import QtGui, QtCore
 from pyqtgraph import dockarea
 
 from artiq.tools import TaskObject
@@ -12,21 +13,78 @@ from artiq.tools import TaskObject
 logger = logging.getLogger(__name__)
 
 
+class _TTLWidget(QtGui.QFrame):
+    def __init__(self, force_out, name):
+        self.force_out = force_out
+
+        QtGui.QFrame.__init__(self)
+
+        self.setFrameShape(QtGui.QFrame.Panel)
+        self.setFrameShadow(QtGui.QFrame.Raised)
+
+        grid = QtGui.QGridLayout()
+        self.setLayout(grid)
+        label = QtGui.QLabel(name)
+        label.setAlignment(QtCore.Qt.AlignCenter)
+        grid.addWidget(label, 1, 1)
+
+        self._direction = QtGui.QLabel()
+        self._value = QtGui.QLabel()
+        self._direction.setAlignment(QtCore.Qt.AlignCenter)
+        self._value.setAlignment(QtCore.Qt.AlignCenter)
+        self.set_value(0, False, False)
+        grid.addWidget(self._direction, 2, 1)
+        grid.addWidget(self._value, 3, 1, 6, 1)
+
+    def set_value(self, value, oe, override):
+        value = "1" if value else "0"
+        if override:
+            value = "<b>" + value + "</b>"
+            color = " color=\"red\""
+        else:
+            color = ""
+        self._value.setText("<font size=\"9\"{}>{}</font>".format(
+                            color, value))
+        oe = oe or self.force_out
+        direction = "OUT" if oe else "IN"
+        self._direction.setText("<font size=\"1\">" + direction + "</font>")
+
+
 class _DeviceManager:
     def __init__(self, init):
-        self.comm = None
-        if "comm" in init:
-            self.comm = init["comm"]
+        self.ddb = dict()
+        self.ttl_cb = lambda: None
+        self.ttl_widgets = dict()
+        for k, v in init.items():
+            self[k] = v
 
     def __setitem__(self, k, v):
-        if k == "comm":
-            self.comm = v
+        self.ddb[k] = v
+        if k in self.ttl_widgets:
+            del self[k]
+        if not isinstance(v, dict):
+            return
+        try:
+            if v["type"] == "local" and v["module"] == "artiq.coredevice.ttl":
+                channel = v["arguments"]["channel"]
+                force_out = v["class"] == "TTLOut"
+                self.ttl_widgets[channel] = _TTLWidget(force_out, k)
+                self.ttl_cb()
+        except KeyError:
+            pass
+
+    def __delitem__(self, k):
+        del self.ddb[k]
+        if k in self.ttl_widgets:
+            del self.ttl_widgets[k]
+            self.ttl_cb()
 
     def get_core_addr(self):
-        if self.comm is None:
-            return None
         try:
-            return self.comm["arguments"]["host"]
+            comm = self.ddb["comm"]
+            while isinstance(comm, str):
+                comm = self.ddb[comm]
+            return comm["arguments"]["host"]
         except KeyError:
             return None
 
@@ -37,10 +95,16 @@ class MonInjTTLDock(dockarea.Dock, TaskObject):
         self.dm = _DeviceManager(dict())
         self.transport = None
 
+        self.grid = QtGui.QGridLayout()
+        gridw = QtGui.QWidget()
+        gridw.setLayout(self.grid)
+        self.addWidget(gridw)
+
     @asyncio.coroutine
     def start(self):
         loop = asyncio.get_event_loop()
-        yield from loop.create_datagram_endpoint(lambda: self, family=socket.AF_INET)
+        yield from loop.create_datagram_endpoint(lambda: self,
+                                                 family=socket.AF_INET)
         TaskObject.start(self)
 
     @asyncio.coroutine
@@ -54,8 +118,11 @@ class MonInjTTLDock(dockarea.Dock, TaskObject):
         self.transport = transport
 
     def datagram_received(self, data, addr):
-        levels, oe = struct.unpack(">QQ", data)
-        print("Received:", hex(levels), hex(oe))
+        ttl_levels, ttl_oes = struct.unpack(">QQ", data)
+        for channel, w in self.dm.ttl_widgets.items():
+            w.set_value(ttl_levels & (1 << channel),
+                        ttl_oes & (1 << channel),
+                        False)
 
     def error_received(self, exc):
         logger.warning("datagram endpoint error")
@@ -76,8 +143,19 @@ class MonInjTTLDock(dockarea.Dock, TaskObject):
                 # MONINJ_REQ_MONITOR
                 self.transport.sendto(b"\x01", (ca, 3250))
 
+    def layout_ttl_widgets(self):
+        w = self.grid.itemAt(0)
+        while w is not None:
+            self.grid.removeItem(w)
+            w = self.grid.itemAt(0)
+        for i, (_, w) in enumerate(sorted(self.dm.ttl_widgets.items(),
+                                   key=itemgetter(0))):
+            self.grid.addWidget(w, i // 4, i % 4)
+
     def init_devices(self, d):
         self.dm = _DeviceManager(d)
+        self.dm.ttl_cb = self.layout_ttl_widgets
+        self.layout_ttl_widgets()
         return self.dm