DIY: 无线电频率+红外遥控器控制相机（Nikon D70）快门
Nikon D70相机没有外接快门接口，但有红外接收器。但红外接收器只能接收到5米以内的信号。要想在5米以外的地方控制Nikon D70，就得用无线电频率控制。我做的这个装置可以在5米以外控制Nikon D70。如果选用另一种发射器线路板，理论上讲，可以在4.3公里控制Nikon D70。
工作原理：
一个数字信号经过一个microcontroller处理成很多零与一的组合后，由一个433 MHz的无线电波经过发射器发射到空气中。接收器接到空气中的信号，接收器中的另一个microcontroller认准是给自己的，就输出一个电压，让optocouple里的LED发光，发出的光促成一个三极管的集电极和发射极形成通路或叫开关，这个开关让第三个microcontroller发出一个38 KHz 的红外信号，这个红外信号被Nikon D70里的红外接收器收到并验证是给自己的，就让快门按下，拍照。
用途：
可以用于不好的工作环境，像太热，太冷，太危险，或你不想老呆在那里的地方。
传播距离：
市场上有433 MHz, 9 V，可以传到4.3 公里的小板块。
主要零件：
2 个 pic16f84a microcontroller
1个 pic12f675 microcontroller
1个 4N25 optocoupler
1个红外发光二极管
几个按钮开关
几个电阻
2个9 V 电池
DIY: RF+IR Trigger for Shutter Release for Nikon D70
In this setup, a button pushed in a 433 MHz transmitter sends a signal to a 433 MHz receiver. When the receiver receives this signal, it activates a LED in an optocoupler. The optocoupler closes a switch which lets a microcontroller send an infrared signal in 38 KHz to close the shutter of camera Nikon D70.
In this setup, I succeeded to transmit from outside with a distance around 10 m and the receiver received signals with the door open. I also tried previously with a 315 MHz transmitter to transmit a signal outside 40 m from a receiver indoors with the door closed.
The setup could be used in some situation which is hard, for example, it is too cold or too hot or too dangerous for you to be there. On the market, there are some 433 MHz transmitter which was claimed to to be capable to transmit in a distance around 4.3 km when powered by 9 V,
https://www.youtube.com/watch?v=TYWAAbjbgDA
