Introduction:

Have you been interested in automating your home, but want to do more than simply turn lights on and off using X10 from Powerhouse or Radio Shack? Have you wanted to integrate infra-red remote control, your hardwired devices such as security alarms and sprinklers, your personal computer and your X-10 controlled devices without paying the big ticket prices of high-tech home automation systems? Well, the Complete Home Automation Controller (CHAC) does just that. This simple cost-effective device does all of those things. It 'connects' your PC via RS-232 to two way infra-red communications, two way X-10 power line carrier communications, hardwired inputs and hardwired outputs!

Usage:

When the CHAC is connected to your computer, you can write simple programs that 'listen' to inputs from virtually any infra-red universal remote controller, hardwired switches and sensors, and X-10 signals from your power lines. Then, based on your program, you can command the CHAC to turn sprinklers on and off, activate alarms and electric door strikes, send X-10 commands to your lights and appliances, or send infra-red commands to your audio/video equipment.

Construction:

After completing part 1 of the construction, you can begin your testing. Construction for each subsequent part is optional, based on your needs.

Part 1: Hardwired inputs and outputs:

Photoplots have been provided if you wish to etch and drill your own circuit board. A fabricated circuitboard is available from the source list. Refer to the diagram for the component locations.

Power Supply:
Install Cpwr, U5, and Ctr3 to provide the CHAC with the required regulated 5 volts. Any 9 volt 500 mA DC power adapter with a center positive 2.1 mm radial connector will be an adequate power source for the project. See the part's list for available sources.

Digital Core:
Begin with the U1 socket. Because this board is a through-hole design, you will need a 52 pin PLCC socket to easily solder to the board. Install all microcontroller support circuitry Rxtal, Xtal, CX1, CX2, Crst, Rrst, RXIRQ, RIRQ, CA2D, and RVh.

RS-232:
Next, proceed to the installation of the RS-232 section. Install U4, U6, SCIC1, SCIC2, SCIC3, SCIC4, SCIC5, Rtx, Rrx.

Inputs
Now, install RA1-RA8, RN1, and CTRA2D.

Outputs:
The output section consists of U3, REL1, REL2, REL3, and REL4, along with CTR1A, CTR1B, and CTR1C.

Part 2: Infra-Red Communication

To allow the CHAC to receive IR commands, simply populate U2 (the IR receiver module) R1, R_IR, C_IR, CTR 4. If you plan to send IR commands, populate Qwake, Rwake, QOFA, ROFA1, and ROFA2. Follow these modification procedures for a Universal Electronics One For All 5 Upgradeable remote control. The modifications are necessary to allow the CHAC to control the remote. A modified OFA remote control and connection cable is available from the source list.

Creating a connection system to the OFA 5

I found the simplest way to connect to this is to use a 3.5 mm stereo plug for communications and a 2.5 mm mono plug for the task of waking up the OFA. Shown here is the OFA after the 2.5 mm and 3.5 mm stereo plugs have been installed. If you reference OFA figure 1, you'll see that these two jacks fit neatly beneath the battery cover and away from the batteries. It's tight, so drill carefully.

Modifying the OFA 5 circuitboard to accommodate a 'remote wakeup signal'

Figure 1

Remove the back of the remote control. Refer to OFA figure 1. There is a cluster of 4 resistors and a diode which are arranged parallel to the microcontroller. Solder a wire on the resistor closest to the diode on the side which is closest to the battery compartment (marked with an arrow) Solder the end of this wire to your 2.5 mm jack. Refer to OFA figure 2 below:

Figure 2

Lastly, you need to connect the transmit, receive, and ground pins to your OFA remote. Since these pins are actually made to accept some sort of connector, I did not want to damage the connection integrity. Therefore, I removed the circuitboard and attached wires to the bottom side of the circuitboard (see OFA Figure 3 below). After your connections to the wakeup resistor and the communication section are complete, carefully re-seat the circuitboard in the case. Route the wires around the battery case as shown in OFA figure 4 below and connect to the phono jacks.

Figure 3

Figure 4

The pinout of the phono jacks are as follows:

2.5 mm: tip connects to the CHAC OFA wakeup circuit (CTR4 Pin 3)
2.5 mm: case is not connected
3.5 mm: tip connects to the CHAC OFA receive circuit (CTR4 Pin 2)
3.5 mm: center connects to the CHAC OFA transmit circuit (CTR4 Pin 1)
3.5 mm: case is connected to the CHAC OFA ground circuit (CTR4 Pin 4)

Part 3: Two way X-10 Communications:

Install Ctr2, Rx10_1 - Rx10_8, Dx10_1 - Dx10_6. Pay close attention to the placement of the diodes. The anodes (black lines) should be facing CtrA - Ctr C as shown on the silk screen. Install Qx10_1 with the flat side facing away from CtrA-CtrC as shown on the silk screen. Install your TW-523 (available from suppliers in the source list) and connect the CHAC to the TW-523 using an inverting four conductor phone cord (also available from suppliers in the source list). Note: An inverting RJ-11 cord is one that when laid flat, the ends are exactly opposite each other. A non-inverting cord has one end flipped opposite of the other end.

Testing / Programming / Programming Examples / Parts List