Canon单反遥控器(英文).docVIP

DIY Canon RC-1 infrared remote control clone This article describes how to build a DIY low-budget AVR-based infrared remote control for Canon cameras. The reverse-engineered communication protocol of the RC-1 is described here. The RC-1 lets you trigger the camera instantly or with a delay of 2 seconds from a distance of up to 5 meters (~16 ft). It comes in very handy when taking long exposure pictures or for HDR photography. The presented circuit can be used as part of DIY interval triggers for smaller Canon cameras without the external trigger connector. In bracketing mode the RC-1 lets the camera shoot a whole series of images at once! It is recommended to read the RC-1 communication protocol description first. The Circuit The first circuit I made was based very much on the original Canon (or Mitsumi, see image above) design. After I got it working, I simplified the schematics successively to reduce the part count and make it more easy to build. The schematics of the initial version is here. The simplified version is shown in the picture below. I was able to trigger an Canon EOS 400D from more then 5 meters (~16 ft) with both versions, though the simple version had more failed trigger attempts. The high-end version uses a crystal oscillator to provide a precise clock to the microcontroller. The IR-LED is driven by an NMOS transistor allowing higher current then the controller outputs can source. The controller is supplied via a diode to reduce the supply voltage below the recommended maximum of 5.5 V. In the simplified version the crystal oscillator was replaced by the internal 8 MHz oscillator, saving three external parts. The disadvantage of this solution is that the frequency is drifting slightly with the supply voltage and temperature. Details on this behaviour can be found in the Electrical Characteristics section of the Attiny25 data sheet. The most radical simplification was the elimination of the transistor. I found out experimentally that driving the