The One Second Dash
August 15th, 2016

The Amazon Dash is a $5 WiFi button that summons a truck to deliver you water or other stuff. Want your Dash to do something else? The popular approach is to sniff its ARP requests. This requires that Dash connect to your network, putting you perilously close to having some DUDE delivered with your IoT mood lighting.

A more immediate problem is immediacy, or lack thereof: the Dash button only connects to your network after being pressed, so there's a ~5 second delay before anything can happen! This makes the ARP Dash hack unsuitable for interactive uses, like doorbells.

Can we make it faster? Here's one way:

  1. "Setup" the Dash with a unique network SSID for a network that doesn't exist
  2. Use a WiFi adapter in monitor mode to observe probe requests on that network SSID

This responds in < 1 second, which is fast enough for real time uses. And you don't even have to give the thing your password.

A Raspberry Pi works when equipped with a WiFi adapter capable of monitoring mode. The RT5370 chipset is so capable - here's the one fish bought. Steer clear of the ubiquitous Realtek RTL8188CUS based devices.

Head on over to the One Second Dash repo to get started!