DIY: 無線電頻率+紅外遙控器控製相機（Nikon D70）快門
Nikon D70相機沒有外接快門接口，但有紅外接收器。但紅外接收器隻能接收到5米以內的信號。要想在5米以外的地方控製Nikon D70，就得用無線電頻率控製。我做的這個裝置可以在5米以外控製Nikon D70。如果選用另一種發射器線路板，理論上講，可以在4.3公裏控製Nikon D70。
工作原理：
一個數字信號經過一個microcontroller處理成很多零與一的組合後，由一個433 MHz的無線電波經過發射器發射到空氣中。接收器接到空氣中的信號，接收器中的另一個microcontroller認準是給自己的，就輸出一個電壓，讓optocouple裏的LED發光，發出的光促成一個三極管的集電極和發射極形成通路或叫開關，這個開關讓第三個microcontroller發出一個38 KHz 的紅外信號，這個紅外信號被Nikon D70裏的紅外接收器收到並驗證是給自己的，就讓快門按下，拍照。
用途：
可以用於不好的工作環境，像太熱，太冷，太危險，或你不想老呆在那裏的地方。
傳播距離：
市場上有433 MHz, 9 V，可以傳到4.3 公裏的小板塊。
主要零件：
2 個 pic16f84a microcontroller
1個 pic12f675 microcontroller
1個 4N25 optocoupler
1個紅外發光二極管
幾個按鈕開關
幾個電阻
2個9 V 電池
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
