Cappy Backend

This repository holds the backend for NU Capstone 2015 Group W5. The backend is written in Ruby, using Sinatra, ActiveRecord, SQLite3, and unicorn. Its purpose is twofold: to serve the JSON views for the application frontend, and to control the other devices.

Getting Started

git clone git@github.com:cappity-cappity-capstone/backend.git
cd backend
bundle
rake db:create
rake db:migrate
bundle exec rake

Development

All development tasks for this application are handled through the Rakefile. To see a complete listing, run bundle exec rake -T.

Schema

For the different devices, we'll be using two tables: devices and states. devices represent the actual devices that are connected, while states represent the state of each device.

device

Here's the basic structure of the devices table:

+--------------------+
| devices            |
+--------------------+
| id:int             |
| device_id:string   |
| name:string        |
| device_type:string |
| unit:string        |
| last_check_in:time |
| created_at:time    |
| updated_at:time    |
+--------------------+

Things to note:

• device_id is the unique id that is reported by the device
• name is an optional string that is set by the user
• device_type should be enforced to be one of the following:
  • lock
  • outlet
  • gas_valve
  • airbourne_alert
• last_check_in is the time that ccs last interacted with the device.

The device has_many states, which is described below.

states

The state table is very straightforward:

+-----------------------+
| states                |
+-----------------------+
| id:int                |
| device_id:foreign_key |
| state:decimal         |
| source:string         |
| created_at:time       |
+-----------------------+

There should be an index on the device_id column to enable quick searching.

schedules

+-----------------------+
| schedules             |
+-----------------------+
| id:int                |
| device_id:foreign_key |
| start_time:datetime   |
| end_time:datetime     |
| interval:int          |
+-----------------------+

A schedule is tied to a device. It begins at a given start time (can be now), and ends at a given end_time, if you want it to. It'll fire every interval within [start time, end time).

Device to Backend API

DeviceType enum

• airborne_alert
• gas_valve
• outlet
• lock

Source enum

• scheduled
• parent_left
• manual_override

Register device

POST /devices

curl -d '{"device_id":"1", "device_type":"outlet", "name": "Toaster"}' -X POST -H "Content-Type: application/json" http://ccs.cappitycappitycapstone.com/api/devices

Body

{
  "device_id": "#{device_id}",
  "device_type": one of DeviceType,
  "name": "Toaster Oven"
}

Responses

201

Newly added device

200

Reattached to previous device

Watchdog timer

PUT /devices/#{device_id}/watchdog

Responses

200

Device exists

404

Device needs to reregister

State devices status

GET /devices/#{device_id}/status

Responses

200

{
  "state": "0.0",
  "source": One of Source
}

404

No known device. Should register

Send alert status

POST /devices/#{device_id}/status

{
  "state": "0.0",
  "source": One of Source
}

Responses

201

404

No known device. Should register