In China, home automation is just starting. CEBus is considered to be a suitable protocol that will satisfy both simple and complex home network. It also enables a slow transfer from traditional house to a highly automated one.
As a feasibility study, the demonstration system mainly contains two simple subsystems: HVAC and Light System, other devices include smoke detector, clock, etc. All the devices can be found and manipulated on the TV screen with a remote controller. But there are no requestor objects in the TV as this is for demonstration purpose only.
Currently the power line is the only media. In the future we will develop more media.
All the devices support CAL and Home Plug & Play, except that the light fixture can only recognize a few simple commands. You can send and receive commands with “CEBus Explorer” – software designed by us.
Domosys PLIII is widely used in our nodes, Intellon’s P300 is used in every light module.
1. Devices List
* Light Control Panel, also acts as a house mode input key pad.
* Light fixtures, able to dim from 0 to 100, ten features defined in HPnP are supported
* Electric Fan, acting as a cooling device.
* Heater, acting as a heating device.
* Thermostat, able to measure the current temperature, accept user set point, and then control Fan and heater.
* Clock, currently only able to keep the time, but in the future, a time schedule and event schedule will be stored in it and control your house as timed.
* Television set, control and monitor center.
* PC adaptor, connecting to PC.
* Fire alarm, as time is too limited, we have to use the PC-adaptor as part of the alarm.
2. Subsystem Connectivity
* Light controller and light fixture
The light controller is a compound node that can control all the lights and set house mode. The light fixture, with small ROM space and reduced function, can only recognize a few messages, such as dim command: 21 2 setvalue C | 31 30, feature select: 21 2 setvalue f | 31, etc. Light controller is the configure master.
* Thermostat, fan and heater are of the same system. Thermostat is a configure master.
* Clock and TV are single nodes that do not belong to any subsystem.
3. Home PnP demonstration
When a new light fixture is first powered on in your house, it will broadcast M15, get a valid address from the light controller and then is able to work. User can control the light on the Light Control Panel. To cancel the setup data in the light fixture, just hold the button for 3 seconds, a bind process will start again.
When the fan or heater is first powered on, it broadcasts a Macro 15, the thermostat will start to configure the new node. To start a new configuration, hold a special button down and then power up the device. This is the same as defined in the HomePnP.
4. Device operation
Push a special button down before power on the device, then hold on for 3 seconds, will cause the device to abort loading any setup data. For master nodes, it will start to hail for system address and unit address. For other nodes, it will broadcast macro 15.
During configuration, the flash of the LED contains special meaning.
Light Control Panel
The light controller is shown in Figure 1
Figure 1. Light Controller
* Press the “Lightx” button will toggle the state of the corresponding light. If the button is held down for more than 0.8 second, the light level will change with predefined step_size and step_rate.
* Press the “Scene” button will set the lights to a user defined scene. To define a scene, just hold the scene button down until all the LED’s on the panel flashes.
* Press the “Enter” button to when your come back, then your house will be in “occupied” mode.
* Press the “Leave” button will make your house enter “unoccupied” mode.
There is only one button on the fan. Each time the button is pressed, the speed of the fan will be changed. The state of the fan will be displayed on the thermostat simultaneously.
* There are four buttons, each contains a LED. The left most LED(first one) indicates the state of the motor. Note that the motor will remain running for one minutes after the heater is stopped.
* The second and third one indicate the current heating power.
* The fourth LED indicates the configuration state during installation.
Figure 2. CEBus Compliant Thermostat
There are 8 buttons:
* Press the left most one(first one) to show the current temperature.
* Press the second one to display the fan state. 0 mean off, 1 means low speed, and so on.
* Press the third one to show the cool setting temperature, press up and down button to modify it.
* Press the fourth one to display the heater state.
* Press the fifth one to show the heat setting temperature, press up and down button to modify it.
* Press the sixth one to set the device work online / offline.
When the current temperature is higher than the cool setting temperature, and the house mode is not in “unoccupied” mode, the fan will be on. When the current temperature is lower than the heat setting temperature, and the house mode is not in “unoccupied” mode, the heater will be on. Note than if the “online” LED is off, this automation will not be generated.
As a sample node, the clock now can only keep and display current time. Modifying the time is an easy process so we will not talk in detail. The time can be read by the other devices, such as TV, as shown in figure 3.
Figure 3. Time is displayed on TV
With the remote controller, every devices can be listed on the TV screen, except the light fixture, which is a simple node. Light level can be modified, clock time is changeable, fan speed is controllable… All these can be done with the remote controller.
The fire alarm is not a single node, but connected to a personal computer, so as to quickly develop the node for demonstration purpose. When smoke is detected, the computer will send an alarm CAL message and then all the lights will flash. In addition, a warning message will be shown on TV.
5. Computer software – CEBus Explorer
CEBus Explorer is still under construction. There are mainly three parts.
CEBus Dialog Box. User can input CAL statement to communicate with the devices. For example, to list devices, do as follows:
* Select global broadcast
* Select ADUNACK packet type
* Select Conditional APDU invoke type
* Type in the “CAL Source” window: ” 0 1 getvalue p”
* Press F9 to send the command, the responses will be shown in the “response” window
The CEBus explorer uses Domosys’ PLIII as transceiver.
CEBus installation window. Please refer to figure 4,
Figure 4. CEBus Explorer – Installation (Click on the image to expand)
User can read all the device information into the computer. They are shown in device-context-object-IV mode, as most of the figures in HomePlug & Play specification. The bind lines are also shown. User can use mouse to draw a bind line, and then write the binding information to device.
CEBus User Interface. This is designed for average users. The Analog Control Object is shown as a virtual knob, Meter Object look like a real meter, etc. User can use the mouse the change them. Unfortunately, this part is still under construction.
6. Typical commands
* List devices [broadcast] 0 1 getvalue p
* Turn all lights on [broadcast] 21 2 setvalue C | 31 30 30
* Turn all lights off [broadcast] 21 2 setvalue C | 30
* Turn the first light on [broadcast] 0A0 21 2 setvalue C | 31 30 30
* Turn the second light to 50% brightness [broadcast] 0A0 21 2 setvalue C | 35 30
For the other commands, when you operate on the TV, you can see them in the CEBus Explorer.