In September, Amazon launched several new devices and provided more information about its low-power wide-area network called Sidewalk. Amid the crush of news was the announcement of a mailbox sensor made by Amazon’s Ring security business. The sensor uses Ring’s proprietary 900 Mhz radio to connect to Ring’s Wi-Fi bridge device that then alerts the user’s phone or Alexa that the sensor has been triggered. It costs $29.99 for the sensor alone and $49.99 for a sensor and bridge.
The device is simple, and if your mailbox is close enough to your bridge it will do exactly what it’s supposed to do: let you know if someone has opened your mailbox. The toughest part of making a mailbox sensor isn’t the sensor (Ring’s uses a PIR-based motion detection sensor), it’s the radio. Getting a signal from inside a metal box and delivering it over a large distance is tough, especially when trying to conserve the battery life of the sensor itself.
Wi-Fi might be able to go most of the distance, but it sucks power. Bluetooth sips power, but can’t travel across a typical suburban lawn, much less a large-rural property. Meeting this challenge is why networks such as Sigfox, Ingenu, and LoRa exist. These networks transmit small bits of data over distances that can range from half a mile to a couple of miles, and they can do it without requiring a lot of power.
Ring is familiar with this problem because it makes several outdoor lights, cameras, and other devices. Camera footage isn’t going to travel over one of these low power networks, but the command to turn on a light or even send a notification that a camera detected motion could.
That’s why Ring and Amazon have created the Sidewalk Network, which Amazon is rolling out slowly by turning on network nodes inside the latest Amazon gear.
I mention all of this because the Ring Mailbox sensor is a Trojan Horse for the Amazon Sidewalk network. Today the sensor doesn’t take advantage of Sidewalk, and it’s only able to send data for what Amazon says is a few hundred feet, and what I discovered topped out around 240 feet. Beyond that, your mailbox sensor can’t talk to the Ring Bridge and so it can’t let you know what’s going on. But at some point, this year Ring says that the sensor will start working on Sidewalk, which will open up the audience for the device to those who need to talk to a shared cluster of mailboxes half a block away or even mailboxes on large properties where a driveway might stretch for 400 feet or more.
This will broaden the appeal of the mailbox sensor and it will also showcase the benefits of Sidewalk specifically, and a low-power wide-area network in general. For example, when setting up the Mailbox sensor, I discovered that locating the Ring bridge in my front hall was too far from the mailbox, at about 255 feet away. The app showed the sensor as offline.
So I had to move the bridge to my garage, which meant it was about 15 feet closer (on a diagonal). Instead of the signal passing through the glass of my front door, it would have to pass through the wall of my garage, which it managed. It also had to pass through a few trees and brush. That worked. My signal strength now varies between poor and fair, but I get the notification.
But once Sidewalk is enabled on the sensor and bridge, I can place the sensor up to half a mile away and still get my notifications. Sending data over that distance, and on a meshed network that could cover entire neighborhoods will show consumers and developers the power of just a little bit of connectivity on a relatively inexpensive device.
With this in mind let’s talk about whether or not you need a Ring Mailbox sensor.
The basic device is pretty simple. It’s a relatively large (2.56-inch by 2.44-inch) PIR motion sensor you can find just about anywhere (it looks just like my original SmartThings motion sensors from 2013). For those of us with a metal mailbox, there’s also an external antenna and cord to attach the antenna to the sensor. The sensor sits inside the mailbox with the antenna outside because a large metal enclosure will otherwise stop radio signals. If you have a plastic mailbox, you can dump the antenna.
If you already have a Ring bridge inside your home, you’ll only need the stand-alone sensor that you can buy for $29.99 By itself, the sensor can’t send data anywhere, because it needs a path to get from its proprietary 900 MHz radio to the cloud. Ring uses a hub called the Ring Bridge to convert the Mailbox sensor data to Wi-Fi, which then ends up in the cloud able to talk to Alexa and the Ring app. You can buy the sensor and the bridge as a $49.99 set.
So is it worth $30 or $50 to know if your mail has arrived? I’d say no since I only check my mail once or twice a week, but I’m apparently not in the majority. A mailbox delivery notification is one of the most popular demands on the IoT Podcast listener hotline. People want to know when their mail has arrived! This makes sense, especially if they are expecting checks or college acceptance letters. Does the Ring Mailbox sensor let you know when mail has arrived? Yes! Every time.
Or rather, the sensor shoots off a notification every time someone opens the mailbox. This means that Ring lets you know when the mail arrives, when someone picks up the mail, and when or if someone opens the mailbox to pop a letter in. As smart home devices go, this one is a little dumb. But it will let you know the mail has arrived unless you live in a place where people are opening your mailbox often for no real reason.
A simple notification shows up on your phone from Ring saying that the Mailbox sensor has detected motion. If you want to get fancy with it, you can tie the Ring notification to Alexa and have Alexa send a notification when the sensor is activated. For those hoping to recreate AOL’s chipper, “You’ve got mail!” notification, you can get close by creating a routine that uses the Ring Mailbox sensor as a trigger and by creating a custom message. If you do this, you can select which Echo in your home should make the announcement.
So the sensor works, but it’s a blunt tool and seems like a lot of money to spend. If I could do it all over again, I would change the setup so the notifications go to my husband instead of me. Because now, every time he’s leaving the house he pops his head into my office to ask, “Did the mail arrive?”
Updated: This post was updated Jan. 11 to note that I can create an announcement for when the mail arrives.