Automation with IR remote control

Infrared remote controls can be used for home automation projects. I started such a project in 2001, using a microcontroller from Atmel 89C series ( either 89C2051 or 89C51). The IR remote control I used was from a Philips TV set (very popular at that time, it was easy to find one if needed). With this automation can be controlled from distance some functions like: light dimming, door locked/open, interphone command, heat control etc.

The program was edited and tested using my own development system [1] and was introduced in microcontrollers with the programmer built by me [3]. The IR protocol used was RC-5, developed by Philips in the late 1980s as a semi-proprietary consumer IR (infrared) remote control communication protocol for consumer electronics.

Figure 1
Figure 2
Figure 3

- power supply from 230VAC socket
- supported microcontrollers: AT89C2051, AT89C51
- one START/STOP output with relay 230VCA
- eight digital outputs open collector
- IR receptor: SFH-5110-36
- optional serial interface RS232 (not included in prototype)
- optional serial EEPROM for various settings (not included in prototype)

Figure 4
Schematic (PDF)
Figure 5
Figure 6
Test prog.
Figure 7
RC codes

Figures 1 and 2 shows a test PCB for verifying that microcontroller was programmed correctly. Figure 4 shows the schematic diagram of the prototype. In figure 5 is an image of the IR remote control I used for testing. Figure 6 shows the program I used to identify the codes of the remote control. You must know that every IR remote control have a set of standard codes, but also there are specific codes that belongs to that IR RC. The program was made for my development system [1]. The codes are sent on serial communication and displayed on PC by monitor program. Figure 7 shows the codes identified by me. After you establish what keys and codes you will use from IR remote control, you can add to the program the correspondence between codes and physical outputs. Then you can burn the program to 89C microcontroller.

Warning: SFH-5110-36 is not a simple IR sensor. It contains all is necessary to decode RC-5 IR information. If you use another remote control is possible to not have RC-5 communication protocol, so you must use another IR receiver.

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[1] - 8051 development system
[2] - AT89C2051 datasheet
[3] - Atmel microcontrollers programmer