Blink: Security cameras with a power and bandwidth-stingy uplink

文章：Brian Dipert

My wife and I live in the Rocky Mountains foothills outside of and above Golden, CO. We’re blessed with an abundance of wildlife here, mostly harmless (elk, deer, rabbits, squirrels, chipmunks, and a diversity of bird species, for example) but in some cases potentially dangerous to us and our pets (bears, mountain lions, coyotes, bobcat, lynx, and the like), notably at night when we can’t see the critters (but they can still see us). Plus there’s the ongoing potential for human-intruder confrontations, of particular concern when I’m away and my wife is still at home.

都说，因此，我们长期以来对我们感兴趣的外部安全摄像头设置。普通读者可能还记得我periodically dabbled(with varying degrees of success) with cameras located in my home’sinterior, particularly when I was splitting my “living” time between multiple locations (sometimes even in multiple states). Exterior use, conversely, incurs some additional complications:

• 天黑后“看到”的能力
• Tolerance of wide temperature extremes
• 水分稳健性
• Ruggedness against high winds,close-proximity lightning strike EMPs，等

And nice-to-haves include:

• Battery power (coupled with long battery life) to preclude the need to run AC wiring, as well as enabling ongoing operation in case of premises power loss (as long as the LAN and WAN don’t go down, of course)
• Wi-Fi支持，以排除运行以太网电缆的需求
• 高清视频捕获功能
• Low initial cost
• 低到不持续的服务成本

我意识到那是一个高个子清单。但是，不管您是否相信，我认为我找到了一个解决方案，可以检查所有盒子。在很小的一部最初是由Kickstarter资助的andas of 2017 part of Amazon。Blink,最初称为即时半导体，成立于2009年作为芯片供应商；it later pivoted to selling consumer electronics systems based on its own silicon (presumably either because it couldn’t find enough external customers for its chips, or was unable to sell them at sufficient profit margin, or some combination of these and/or other factors).

眨眼系统由一个或多台微型摄像机组成，每个相机都直接连接到通用路由器，或通过Wi-Fi连接到接入点中介（以及从那里到Internet），以及通用（同样小的）同步模块控制点（然后本身通过Wi-Fi连接到同一路由器或接入点中介）专有“ LFR”远程900 MHz频道:

同步模块的目的可能对那些（像我一样）使用独立摄像机的人可能不直觉……直到您意识到每台相机都可以逃跑up to two yearson asingle set of two AA lithium cells。也许显然，这种功能的sting不休排除了每台相机的连续视频，这是一个“约束”，它也可以整齐地保留可用的LAN和WAN带宽。Instead, the Android or iOS smartphone or tablet app first communicates with the Sync Module and uses it to initiate subsequent transmission from a network-connected camera (generic web browser access to the cameras is unfortunately not available, although you can also view the cameras’ outputs from either a standalone Echo Show or Spot, or aKindle Fire Tablet以回声表演模式）。

The company initially offered two product lines: white-color, 720p-resolution, and interior-intended Blink cameras, and the incrementally more expensive black-color, 1080p-resolution, outdoor-intended Blink XT models that I have. Sync Modules are compatible with both camera types; as long as the 900 MHz control beacon reliably reaches far enough, and subject to a 10-camera-per-module limit (which can be further extended by multi-module setups) you can even mix-and-match both camera models within a common network. Initially, I bought a two-camera-plus-module kit on sale for $149:

后来，我补充了那些另外三个独立摄像机的人：

眨眼XT是随后被眨眼XT2取代, although a close comparison of the specs indicates a more modest update than the hype might suggest at first glance. Both models support 1080p video (via a firmware upgrade to the original 720p on the Blink XT), both support region-based motion triggering (again via firmware upgrade on the Blink XT), and both claim up to two years of battery life (usage-dependent, of course, and perhaps more realistically achievable on the XT2). The primary differentiator I see is that whereas both product generations embed a microphone, the XT2 also integrates a speaker for two-way audio communication … useful with a front door-mounted camera, I suppose, but I doubt a mountain lion on the deck will be scared away by the sound of my voice!

The delay between requesting live video from a particular camera and the start of transmission from that camera is a few seconds at most, and the full-color daylight image quality is impressively solid, with wide angle-of-view. There’s no optical zoom or pan-and-tilt capabilities, but neither feature is particularly amenable to harsh-environment outside usage, anyway. And the images captured after dark are more useful than I would have imagined beforehand. Unlike other (more expensive) cameras, the Blink XT units don’t integrate an infrared light transmitter, which would have limited illumination range anyway. Instead, the image sensors’ infrared filters can be selectively disabled for broader-spectrum ambient light passage in exchange for monochrome, lower-resolution images (to be clear, given that the alternative is没有images, this is an absolutely acceptable tradeoff!).

Last (at least for now) but not least, what about all-important privacy? As earlier mentioned, the LFR connection between each camera and its Sync Module nexus is proprietary; a thorough Google search I made in the hopes of revealing its secrets was fruitless. All Blink network nodes (cameras and Sync Module) also leverage Wi-Fi, complete with whatever encryption scheme you’ve implemented on the LAN. Keep in mind, though, that you’re also able to view live camera streams via a WAN connection, and don’t forget about the motion trigger-activated and “cloud”-stored video clips (with no accompanying monthly service fee, by the way, although duration-limited to 7,200 total seconds of video).

据我的研究所知，WAN上的实时或存档视频传输并非超出普通数据包的范围。而且我想从理论上讲，黑客（或流氓员工）也可以访问存储在Blink的服务器上的视频剪辑，而Rogue Employee也可以远程控制实时相机视图。都说过，一个post I foundfrom Blink’s director of customer support on the company’s community discussion forum is quite emphatic and pretty definitive:

We are not able to see your video, clips or turn on your camera video or make the mic “hot”. Like any vendor that has thought about the service side of these types of products, we’ve built in a lot of remote diagnostics.

Yes, we can send diagnostic triggers, like alerts or reset the camera, see timestamps, duration of clips, last clip times and devices that recorded. We can see Wifi and LFR signal strength, battery voltage, battery drain, usage statistics.

我再说一遍，我们不会，也不能远程控制您的相机视频或音频，这是出于明显的原因。

我在本系列中的下一篇计划博客文章将涵盖眨眼硬件和相关软件的初始安装和正在进行的操作，除其他方面详细介绍了体验的客户友好程度。在此之前，与往常一样，我在评论中欢迎您的想法！

—Brian Dipertis Editor-in-Chief of the Embedded Vision Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the company’s online newsletter。