Making Things Talk

Identification

In the previous chapters, you’ve assumed that identity equals address.

Once you knew a device’s address on the network, you started talking.

Think about how disastrous this would be if you used this formula in

everyday life: you pick up the phone, dial a number, and just start talking.

What if you dialed the wrong number? What if someone other than the

person you expected answers the phone?

Networked objects mark the boundaries of networks, but not of the

communications that travel across them. We use these devices to send

messages to other people. The network identity of the device and the

physical identity of the person are two different things. Physical identity

generally equates to presence (is it near me?) or address (where is it?),

but also takes into consideration network capabilities of the device and the

state it’s in when you contact it. In this chapter, you’ll learn some methods

for giving physical objects network identities. You’ll also learn ways that

devices on a network can learn each other’s capabilities though the

messages they send and the protocols they use.

9

MAKE: PROJECTS

Sniff, a toy for sight-impaired children, by Sara Johansson.

The dog’s nose contains an RFID reader. When he detects RFID-tagged objects, he gives sound and tactile feedback,

a unique response for each object. Designed by Sara Johansson, a student in the Tangible Interaction ...