Examples:

Application example:

Now, your applications using the CHAC are endless. However, this example will employ every media on the CHAC. Refer to the Application Example diagram.

Example Problem Statement:

Employ a home automation system to provide the following:

Task 1:

Upon a doorbell ring:

• Turn on the porch light and the foyer light
• Pulse the doorbell relay
• Mute the television

Task 2:

Upon receipt of the 'Evening Time' infra-red command

• Turn off all lights in the house
• Turn on the living room light and dim it to 50%
• Pulse the door lock relay
• Set 'all secure' indicator
• Turn on the television

Task 3:

Upon receipt of the 'Bedtime X-10' command:

• Turn off all inside lights
• Turn on outside lights
• Turn off all audio/video equipment
• Turn on bedside lights and dim to 20%
  

Task 4:

Upon a reset button input, reset the 'all secure' condition

First thing we need to do in our design is to assign all our inputs and outputs to CHAC protocol messages: Refer to the Example Diagram

Inputs:

• 1. Doorbell ring: connected to IN0 CHAC message response will be 'D00'
• 2. Evening Time IR command (Assign this to '1') CHAC message response will be 'R1'
• 3. Bedtime X-10 Command (Assign this to House Code B, All Units Off) CHAC message response will be 'XBH'
• 4. Remove 'all secure' condition "D10"

Outputs:

• 1. Turn On Porch light and Foyer light: (Say porch light is House Code A, Unit 1, and Porch Light is House Code A, Unit 2): CHAC command is 'WA1A2AJ<CR>
• 2. Pulse Doorbell Relay (connected to Relay 1) CHAC command is 'OAP<CR>'
• 3. Mute the television: CHAC command is 'Q{^K}4<CR>'
• 4. Turn off all lights inside house (assume House Code A) CHAC command is 'WAH<CR>
• 5. Turn on the living room light and dim 50% (Assume living room light is House Code A, Unit 3) CHAC Command: 'WA3AJAL8<CR>
• 6. Pulse Door Lock Relay (Door Lock Relay is connected to Relay 2) CHAC command: 'OBP<CR>'
• 7. Set 'all secure' indicator: All secure indicator is connected to output E: CHAC command is 'OE1<CR>'
• 8. Reset 'all secure' indicator: CHAC command is 'OE0<CR>'
• 9. Turn on the Television: CHAC command is 'Q{^K}{^D}<CR>'
• 10. Turn on outside lights: Assume the lights are House Code A, Units 3 and 4: 'WA3A4AJ<CR>'
• 11. Turn on bedside lights to 20%:' Assume bedside lights are house code A, Unit 1. CHAC command 'WA1AL8<CR>'

Refer to the Basic Program listing below for implementation using Microsoft Quickbasic:

Construction / Testing / Programming / Parts List