Infrared Receiver Serial Port (RS-232)

2007-07-16T17:58:00.000-07:00

If you surf a bit around IR pages, you will probably find several simple circuits that connect almost directly the output of the IR receiver to certain line of the computer serial or parallel port. In the group of circuits for the serial port is the original LIRC (Linux Infrared Remote Control) circuit. Also commercial solutions like the discontinued Packard Bell Fast Media Remote and the more recent Animax Anir Remote. All them connect the output of the IR receiver to the DCD [data-carrier-detect] line (called RLSD [receive-line-signal-detect] in the Windows API) of the serial port. This is of course the simplest way to get the infrared data into the computer, but it also means that now the computer needs to make all the decoding work. Comparing the LIRC circuits and the ones used in the Animax and PB Fast Media receivers, it is very evident the use in the commercial circuits of an additional transistor and the TxD line of the serial port. This is a way to give good RS-232 voltage output levels for the DCD line (positive and negative; TxD acts as a negative voltage reference). The variation between 0 and +5 volts given by the output of the IR receiver and applied directly to the DCD line may not always be understood by the serial port as a state change in that line. The power supply is always based on the activation of the RTS and DTR lines from the computer side, so that we obtain the positive voltage required for the IR receiver. By using both lines we can obtain more current without loosing voltage level. Depending on how much you appreciate your IR receiver, you may choose to use a single resistor, a zener type diode or a fixed voltage regulator to give power to it. Because the resistor solution may not give the correct voltage and the zener use is not very efficient (or we are not trying to cut circuit costs to be commercially competitive), it seems better to use the 78L05 serial regulator to obtain a fixed output of +5 volts.

Relay Circuit for Remote Control

2007-07-15T20:14:00.000-07:00

this relay Circuit drive from RC logic

Simple Remote Control 3 Bit

2007-07-15T20:00:00.000-07:00

Simple Infra Red Remote Control 3 Bit

Remote control Using HT-12A

2007-07-11T19:02:00.000-07:00

Features
· Operating voltage -2.4V~5V for the HT12A
· Low power and high noise immunity CMOS technology
· Low standby current: 0.1mA (typ.) at VDD=5V
· HT12A with a 38kHz carrier for infrared transmission medium

Applications
· Burglar alarm system · Smoke and fire alarm system · Garage door controllers · Car door controllers

General Description
The 212 encoders are a series of CMOS LSIs for remote control system applications. They are capable of encoding information which consists of N address bits and 12-N data bits. Each ad-dress/data input can be set to one of the two logic states. The programmed addresses/data are transmitted together with the header bits

Remote Control Schematics

Infrared Receiver Serial Port (RS-232)

Relay Circuit for Remote Control

Simple Remote Control 3 Bit

Remote control Using HT-12A