HVAC demo version 0.2

Copyright (C) 2014, Jaguar Land Rover

This document is licensed under Creative Commons Attribution­ShareAlike 4.0 International.




HVAC DEMO ­ VERSION 0.2
This document describes the purpose, setup, and launch of the HVAC demo that is the first milestone of the RVI
project.




BACKGROUND
The remote HVAC control demo is a part of the Automotive Grade Linux project where the Tizen IVI climate control
(HVAC) screen can be remotely controlled from a mobile device. Updates made to the IVI HVAC screen are sent in
real time to the mobile device, and vice versa.

An initial release of the remote HVAC demo was done using the MQTT protocol (See http://mqtt.org). The first
milestone of the RVI project will migrate the HVAC demo to the RVI technology.




READER ASSUMPTIONS
The reader is assumed to be able to:

 1. Have a basic understanding of Linux directory structures.
 2. Start and stop programs on the RVI­hosting system




PREREQUISITES
 1. Erlang runtime R16B01 or later has to be installed on the hosting system.

 2. Git is installe don the hosting system.




DEMO COMPONENTS
In order to test the RVI milestone 1 without having to bring up a complete Tizen IVI and mobile device environment,
a simple emulator for these two components have been provided in hvac_emulator.py and mobile_emulator.py

All components can be run on a single system.

Please see schematics below for an overview:
Figure 1. Demo schematics. See HVAC and mobile device emulator chapters for details




DEMO SETUP
Two RVI nodes, both hosted by a single machine, will be involved in the test:

The backend RVI node will the mobile emulator (mobile_emulator.py). The vehicle RVI node will host the HVAC
emulator (hvac_emulator.py).

See build instructions for details on the prerequisites for building and running the demo.




CHECK OUT THE RVI SYSTEM
 git clone https://gerrit.automotivelinux.org/gerrit/RVI/rvi




SWITCH TO V0.2 OF THE RVI SYSTEM
The cloned gerrit repo contains all tags and branches. Switch to tag v0.2 to get a release that does not contain daily
snapshots.

 cd rvi
 git checkout v0.2




COMPILE THE RVI SYSTEM
 make




CREATE THE VEHICLE DEVELOPMENT RELEASE
See ../CONFIGURE.md for details on the configuration process.

From the rvi root directory, setup the vehicle node:

 ./scripts/setup_rvi_node.sh ­d ­n vehicle ­c hvac_demo/vehicle.config


The new developer release will be created in a subdiretory named vehicle




CREATE THE BACKEND DEVELOPMENT RELEASE
In a similar manner, setup the backend node:

 ./scripts/setup_rvi_node.sh ­d ­n backend ­c hvac_demo/backend.config


The release will be created in a subdiretory named backend




DEMO LAUNCH

LAUNCH THE BACKEND RVI NODE
In its own window, launch the backend rvi node that the subscription service and mobile device emulator will
connect to.

 ./scripts/rvi_node.sh ­n backend


Make a note of the Service Edge URL address printed out by the logging service.




LAUNCH THE VEHICLE RVI NODE
    Please note that the backend node must be started before the vehicle node. *

In its own window, launch the vehicle RVI node that will serve the HVAC emulator.

 ./scripts/rvi_node.sh ­n vehicle


The VIN number that will be used by the mobile device are the digits at the end of the "Node Service Prefix" printed
out at the end of the launch process.
By default, the hvac_demo/vehicle.config file has its node_service_prefix entry set to
jlr.com/vin/1234/, yielding a VIN of "1234".




LAUNCH THE HVAC EMULATOR
In its own window, launch the HVAC emulator and have it connect to the vehicle RVI node.

 cd hvac_demo
 ./hvac_emulator.py http://127.0.0.1:8811


Modify the http://127.0.0.1:8811 to match the Service Edge URL reported by the vehicle RVI node.

At startup the HVAC emulator will report the VIN number that it is associacted with. (Default 1234)

The HVAC emulator accepts [key] [value] input lines that are distributed to all mobile devices controlling the VIN of
the vehicle RVI node.




LAUNCH THE MOBILE DEVICE EMULATOR
In its own window, launch the mobile device emulator and have it connect to the backend RVI node.

 cd hvac_demo
 ./mobile_emulator.py http://127.0.0.1:8801 +1941231234 1234


Modify the http://127.0.0.1:8801 to match the Service Edge URL reported by the backend RVI node.

The phone number (+19491231234) is arbitrary, but has to be unique across all running mobile device emulators.

The VIN number (1234) is the VIN number reported by the HVAC emulator at startup.

The mobile device emulator accepts [key] [value] input lines that are distributed to the vehicle with the matching
VIN.




DEMO EXECUTION

SEND VALUES FROM MOBILE TO HVAC EMULATOR
Any [key] [value] entered in the mobile device emulator will be sent up to the subscription service and forwarded to
the HVAC emulator.




SEND VALUES FROM HVAC TO MOBILE EMULATOR
Any [key] [value] entered in the HVAC emulator will be sent up to the subscription service and forwarded to the
mobile emulator.




EXIT PROGRAMS
Terminate the mobile device emulator by entering "q" followed by enter.

Terminate the HVAC emulator by entering "q" followed by enter.

Terminate the subscription service by pressing Ctrl­c.

Terminate the vehicle RVI node by pressing Ctrl­c Ctrl­c.

Terminate the backend RVI node by pressing Ctrl­c Ctrl­c.




HVAC EMULATOR TECHNICAL DETAILS
The HVAC emulator simulates an HVAC application unit installed in a vehicle.

The emulator connects to the Service Edge of the vehicle RVI node, started with "rvi_node ­n vehicle" and registers
two services with it:

     jlr.com/vin/[vin]/hvac/subscribe
    Used by the mobile emulator to subscribe to updates entered on the HVAC emulator's command line.

     jlr.com/vin/[vin]/hvac/publish
    Used by the mobile emulator to report updated values entered on its command line

In both cases, jlr.com/vin/[vin] is the vehicle RVI node's service prefix specified in vehicle.configure­
> env­> rvi­> node_service_prefix.

The mobile emulator invokes the subscribe service above in order to receive new HVAC values published by the
HVAC emulator.

When a new key/value pair is entered on the HVAC emulator's command line, The mobile emulator services
registered through an /hvac/subscribe message will be invoked with the key, value, and VIN number of the HVAC's
RVI node. The receiving mobile emulators will print out the information.

If a new key/value pair is entered on a mobile emulator's command line, they will be sent to the HVAC emulator's
/hvac/publish service, which will print them on screen.




MOBILE DEVICE EMULATOR TECHNICAL DETAILS
The mobile device emulator connects to Service Edge of the backend server, started with "./rvi_node ­n backend",
and subscribes to HVAC updates (temp, fan speed, etc) updates from the vehicle with a given VIN.
At startup, the mobile emulator will do two things:

 1. Register a service with the backend RVI node
    This service is invoked by the HVAC emulator to transmit key/value pairs entered on its commandd line.

    The service name has the following layout:

     jlr.com/backend/mobile/[phone_nr]/hvac/publish

    The jlr.com/backend prefix is the backend RVI node's service prefix specified in backend.configure­
    > env­> rvi­> node_service_prefix.

    The [phone_nr] is the phone number specified on the command line when the mobile emulator is started.

 2. Send a suscription request to the HVAC emulator
    The HVAC emulator's subscription service is invoked as

     jlr.com/vin/[vin]/hvac/subscribe

    where [vin] is the command­line specified VIN of the vehicle RVI node to connect to. The subscription
    request's single parameter is the full name of the publish service registered in step 1. When the HVAC emulator
    has a key/value pair entered at its command line, the key/value/vin will be sent to the publish service on the
    mobile emulator.

    When a new key/value pair is entered on the mobile emulator's command line, simulating screen input on the
    HVAC app, the key/value pair will be sent to:

     jlr.com/vin/[vin]/hvac/publish

    The HVAC emulator will receive the published key/value pair and print it on screen.