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Servo controlled infrared transmitter

Application examples:

- Remote control for a camera on a RC-model through normal servo channels.

- Control for a TV at home. Doorbell connected to one input - switches the TV to a surveillance cam.

- Control for a stereo at home. Motion sensor connected to one input - pump up the volume to scare a housebreaker.

The idea for this project came up, to control a HD-camcorder on a Mikrokopter with a second radio-transmitter.

Gas-Stick: Zooming Camera

3-way Switch: Stop/Picture/Movie record

Nick-Stick: Cameraholder-Nick

Roll-Stick: Cameraholder-Roll

Inputs:

2 channels for servo-signals, switches or other TTL signals

1 IR-Receiver to learn new codes (36 - 40 kHz)

Output:

Modulated infrared signal at 950 nm

Controls:

1 LED to indicate several operating modes

1 button to enter/leave the learning mode and switch between single and multi mode

Supply voltage:

5V DC @ 50 mA

(Attention when using RC-Receivers with higher voltage)

Theory of operation:

Each channel is seperated into 5 states, depending on the positive pulse width:

0,00 - 0,74 ms => 0 (switch to GND)

0,75 - 1,24 ms => 1 (stick down)

1,25 - 1,74 ms => 2 (stick middle)

1,75 - 2,24 ms => 3 (stick up)

2,25 - more ms => 4 (switch to VCC or open input)

Together with the second input, you get theoretically 25 different combinations, which all can be populated with learned IR-code.

When using servo signals only, you have 3 states per channel, so 9 combinations.

When using switch signals only, you have 2 states per channel, so 4 combinations.

When mixing both signals, you have 2 states for the switch and 3 states for the servo, so 6 combinations.

When using only one channel, you get 2 (switch) or 3 (servo) states.

After power-up, the device checks the inputs the whole time. When a combination was learned with an IR-Code before, this code is sent out through the IR-Diode. Depending on which mode this combination was learned, it is sent out only once (single-mode), or as long as the combination stays active (multi-mode).

When the device sends out IR-Code, the red LED lights up.

Theory of learning:

When you press the button on the device, it goes to learning-mode.

In this mode, the LED flashes 1 or 2 times (depending of the actual mode) every half second, indicating that the device is waiting for IR-codes.

When pressing the button again, you can choose between single- or multi-mode.

When an IR-code is sent to the device, it looks at which state-combination the inputs are, and saves the IR-code for this combination.

Saving is confirmed with fast flashing of the LED.

You can now learn multiple combinations with different (or same) IR-codes, you can even mix up different IR-protocols and use different modes on different combinations.

When you have learned enough, press the button for 2 seconds, to permanently save the data to the EEPROM. This is confirmed with fast LED-flashing.

The device goes back to normal operation and is ready for orders.

Currently supported IR-Protocols

Protocol:   Used by

===================

GRUNDIG     Grundig

JVC         JVC

KASEIKYO    Panasonic, Technics, Denon and more japanese manufacturer, which are member in "Japan's Association for Electric Home Application"

NEC         NEC, Yamaha, Canon, Tevion, Harman/Kardon, Hitachi, JVC, Pioneer, Toshiba, Xoro, Orion, NoName and much more japanese manufacturer

NIKON       Nikon

NOKIA       Nokia, e.g. D-Box

RC5         Philips and more european manufacturer

RECS80      Philips, Nokia, Thomson, Nordmende, Telefunken, Saba, Technisat

SAMSUNG     Samsung

SIRCS       Sony

The code was compiled using WinAVR-20081205. Other versions generate much bigger code which don't fit in the ATMega8 anymore. To avoid this, use another WinAVR version or disable some IR-protocols in irmpconfig.h and irsndconfig.h

This project is based on the nice IR decoder/encoder routines (IRMP/IRSND) from Frank Meyer => http://www.mikrocontroller.net/articles/IRMP