Hacking the Motorola Blink 1 Baby Monitor (Part 2)

Ok, so it’s been quite some time since I posted my first efforts at “hacking” the Motorola Blink 1 Baby Monitor. Suffice to say we’ve been quite busy for a while & I’ve only just gotten around to actually plugging it in again now that our son is with us & at an age where we’re starting to think about being able to put him down in his crib & go into another room.

Anyway, I powered it on for the first time since August today and it asked to perform a firmware upgrade. I though ‘Aha! I’ll capture what it’s up to and see if I can work out where it downloads new firmware from’ but I inadvertently messed-up my tcpdump session & didn’t actually capture anything while it was upgrading. Furthermore, as I should have known from reading the comments here it seems that Motorola have disabled the landing page for the onboard web-server in the new firmware version (08-050) and it now just gives you a 404.

Well obviously this couldn’t be allowed to stand. Suffice to say if you capture all network traffic from the Blink when it powers on you’ll see it makes some web requests to a Monitor Everywhere ‘OTA’ server. It seems this is how it determines if there’s a firmware upgrade to be downloaded & with a bit of jiggery-pokery you too can download bmfwromfs_08_050.tar.gz which contains the latest firmware.

Unpacking the gzip’d tarball you’ll see there is a binary file ‘conprog.bin’ which I’m pretty sure is the kernel image  (2.6.17.14 since you ask) and a file ‘rootfs.bin’ which is a romfs image file containing the root file system for the camera.

You can mount this under Linux using the command:

mount -t romfs -o loop <path to rootfs.bin> <mount-point>

I’ve only just got this going tonight so I’ve yet to have a real poke around in there but for everyone who’s looking for the web interface point your brower at:

http://<camera-ip>/blinkhome.html

– or –

http://<camera-ip>/index2.html

to get it back. Incidentally the pages aren’t quite the same, so worth looking at both!

 

Hacking the Motorola Blink 1 Baby Monitor (Part 1)

As I mentioned before I’ve recently acquired a Motorola Blink 1 Wi-Fi baby monitor. My plan was to reverse engineer some of its functions in order to integrate it with our existing home automation. My findings to date indicate that it should be fairly easy to interface with the monitor without using the Monitor Everywhere App.

The first step was just to point a web browser at the camera’s IP address which paid off by giving me the following (with no authentication incidentally – be careful if you might be putting one of these on a publicly accessible IP):

Motorola Blink 1 Web InterfaceYou get a web interface with Javascript based video streaming & control Pan & Tilt as well as a reading of the current temperature & controls for contrast, brightness & image resolution. Two resolutions are available: QVGA (320×240) & VGA (640×480). On this page the video stream is provided by using some Javascript to repeatedly load a JPEG image from the URL:

http://<camera-ip>/?action=snapshot

and replacing the existing page image with it. Control of pan & tilt is also done with AJAX HTTP requests, I’ve not done any experimenting with those yet so I’ll leave them for another time. It is also possible to read the temperature sensor value in °C by requesting the following URL:

http://<camera-ip>/?action=command&command=value_temperature

 

The link for “Video + Audio” takes you to an identical looking page but instead of using Javascript to provide the video it using a Java applet to playback an MJPEG stream with audio. The Java applet appears to be based on the Cambozola streaming image viewer by Andy Wilcock. The URL for the MJPEG stream is:

http://<camera-ip>/?action=appletvastream

It seems possible to playback the video stream perfectly happily using VLC (just point it at the URL) but so far I can’t get it to play any audio with VLC. Unjar’ing the cambozola.jar from the Blink makes me suspect there could be an ADPCM audio stream (there is an ADPCMDecoder.class in the JAR) but it’s not obvious from capturing the stream’s URL with wget – if anyone knows anything about audio encoding in MJPEG streams I’d be most interested to hear about it.

One final point of interest from the web interface is that the page title identifies the Blink 1 as the MBP2000W which I’m guessing is the Motorola internal model number for the device.

Having explored the web interface a bit I thought I’d look into what sort of network traffic the Blink was generating. Having whipped out arpspoof & tcpdump I can confirm that the Blink is chatty little thing. On start-up it registers itself with the Monitor Everywhere website (it seems to use its own MAC address as the key), it seems to generate lots of ICMP traffic (mostly echo requests) & there’s definitely some STUN stuff going on (presumably to allow access to the camera from outside of your local network). I’ve got some network captures that I’ll be spending some time analysing in the near future.

One thing I did notice is that it’s fairly easy to receive alerts from the camera when it detects a noise. It just sends out a UDP subnet broadcast on port 51110. The contents of the UDP packet are:

VOX:<Camera MAC Address>

You can test this for yourself just by using netcat to listen on UDP port 51110 like so:

netcat -l -u 51110

That’s all I’ve got so far but I’ll post some more info when I’ve got some. In the meantime, happy hacking!

Motorola Blink1 Wi-Fi Baby Monitor

Discovering that we were expecting our first child at the end of the year naturally meant it was time to shop for exciting new gadgets that will make parenting a walk in the park (ha!). Top of that list came the acquisition of a baby monitor.

We’d seen a wireless video baby-monitor (with pan & tilt) that some friends of ours had bought. It looked ideal as it came with a neat little portable display unit & had all the required features (night vision, sound alert, talkback, temperature monitor etc). Unfortunately on further investigation I discovered that it transmitted video over the unregulated 2.4GHz band which meant that when the baby monitor was on it stomped all over their Wi-Fi signal. This seemed like a bit of a show-stopper to me.

Fortunately there are a few video baby monitors on the market which transmit their video over Wi-Fi meaning they should play nicely with the Wi-Fi. After a bit of research I decided to go with the Motorola Blink 1, it has all the features we wanted (temperature & sound alert, talkback) and also has an Apple & Android app (called Monitor Everywhere) which allows you to view the camera on your phone or tablet at home and also when away from home (should you so wish). You can also log into the Monitor Everywhere website to view your camera from any web browser. We bought ours from Amazon for £75 and got a £25 discount for joining Amazon Family which meant we got the Blink for £50 – bargain!

The slight downside to the Blink is that it doesn’t come with a dedicated video display. Obviously the intention is that you’ll use your phone or tablet to monitor it so you don’t need one. We decided to set up Katy’s Nexus 7 (which rarely gets used at home) as a display using the official charging dock which allows it to charge while sitting in the correct orientation for viewing video.

So far the experience is pretty positive. The set-up was straightforward & all done via the app (in this case the Android one) including adding the monitor to our Wi-Fi network. Once on the Wi-Fi it automatically downloaded & installed a new firmware update. After that it just appeared as a camera available to be viewed in the app. My two complaints about the current version of the app are:

  1. It doesn’t keep the screen of the device on when you’re viewing the camera
  2. If there’s no background noise the audio stream from the camera makes a periodic “purring” noise

Because it’s a Wi-Fi camera, it should be possible to reverse-engineer some (or all) of its functions and maybe make it do some cool stuff. Things I’m thinking of so far are:

  • Pause playback on the media centre / squeezebox when the monitor detects a noise
  • Provide some visual cue (LED strip or something) when noise is detected
  • Log & graph the temperature in the nursery
  • Automatically launch the app & turn on the screen of the Nexus when noise is detected

I’m sure there’s a bunch of other stuff it could also do. Anyone got any suggestions?Anyway, I’ll be documenting my discoveries here and hopefully they’ll be useful to other Geek Dads / Dads-to-be.