Sound Activated Camera - DIY electronics project

A sound activation circuit that will control the digital camera shutter release button.

Figure 1 - This is the relay interface that controls the camera shutter switch

The small board shown in the left of Figure 1 is a previous project called "Camera Trigger Hack", and it allows any electronic device to issue a focus and shoot command to the camera. I call this a hack because it requires removal of the original switch from the camera in order to hack into the two functions that control the focus and shoot signals on the cameras circuit board.

You "may" be able to build this project without the previous project as long as your camera board will accept the 5 volt digital signals from the 74121 one-shot into the cameras board, but to be safe, this previous project adds a level of safety to ensure your camera will not be damaged by any external device or voltages.

The small circuit board shown in the right of Figure 1 is the board that will be presented here, and it consists of a small microphone, an op-amp preamplifier (LM358), and a digital one-shot switch (74121), which controls the pulse time to the relay board that will trigger the shutter release switch. The one-shot is needed as the camera expects the shutter release to be pressed down by a human, and the pulses sent from the microphone preamplifier will be much too short to be taken seriously by the camera. The one-shot takes this millisecond input pulse and then sends out a digital pulse for a duration that is long enough for the camera to respond.

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Repeating Camera Timer - DIY electronics project

An adjustable timer that will continually focus and shoot images on a digital camera.   

      

This system will focus and shoot a photo at some repeating interval This project will extend the "Hacked Camera Trigger" project, allowing a timer to control both the focus and shutter release functions on a digital camera at an adjustable rate. This method of repeating time delayed image taking is also referred to as a "time lapse photography", and can be used to speed up time by piecing together hundreds of photos taken over the span of hours or even days. By first focusing the camera before the shot, the camera will be able to acquire moving targets with far fewer missed or blurry exposures. In this project, a timer feeds a 10 stage counter, allowing up to 10 individual control points, although only two are needed in order to control the camera relay interface. By using the other eight digital output pins on the decade counter, several more cameras can be controlled, or more relays can be added to allow the controlling of various other electrical devices such as solenoids, alarms, lights, or even AC operated appliances. The rate of photo taking can be controlled by a variable resistor, and by altering the value of the timer capacitor, rates of several photos per second all the way down to single photos every hour can be set. This project assumes that you have previously built the "Hacked Camera Trigger" project, although you could certainly interface it to some other hardware as well. Figure 1 - This is the relay interface that controls the camera shutter switch The small board shown in Figure 1 is a previous project called "Camera Trigger Hack", and it allows any electronic device to issue a focus and shoot command to the camera. I call this a hack because it requires removal of the original switch from the camera in order to hack into the two functions that control the focus and shoot signals on the cameras circuit board. You "may" be able to build this project without the previous project as long as your camera board will accept the 5 volt digital signals from the 4017 decade counter into the cameras board, but to be safe, this previous project adds a level of safety to ensure your camera will not be damaged by any external device or voltages.

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Invisible Light Basics DIY tutorial

An introduction into using infrared radiation to create stealthy night vision spy gadgets 

Infrared radiation can illuminate a scene for night vision operations Night vision is one of the most important factors when considering any kind of video operated spy gadget as this technology allows the viewer to see in complete darkness while the subject is completely unaware. Because infrared light (radiation) falls just below red on the visible light spectrum, making up the wavelengths from about 750 nanometers to about 1500 nanometers, this light cannot be seen by human eyes, but it can easily be seen by many video cameras, making it useful as a covert lighting method in night vision systems. A common example of infrared light is the medium for communication between your remote control and television set. The LED on the end of your remote sends out pulses of infrared light which is received by the infrared detector on the TV and demodulated back into data. Of course, you cannot see the pulses because they are out of our visual range, but the infrared receiver in the television can see the pulses perfectly. Security cameras and mini spy cams can also see infrared radiation very well. They are easy to connect, inexpensive and can be easily hidden. There are many good quality security cameras available on the market that include a low lux video camera in a weather proof housing along with an array of infrared LEDs for night vision applications. Black and white security cameras and small board cameras are particularly sensitive to infrared light. These ultra low lux cameras can usually be purchased for about $100 or less, especially from online sellers. Add 10 or more infrared LEDs, and you now have a night vision system that is better than those that sold for thousands of dollars in the 1980s. Figure 1 - The light spectrum, showing the small segment we call visible light The light spectrum shown in lower half of Figure 1 covers light from ultraviolet right to infrared and shows the small portion of the light spectrum that can be seen by human eyes. Light is visible to our eyes from approximately 400 nanometers (violet) to approximately 700 nanometers (red), and has green (550 nanometers) at the midpoint. What is interesting is that the imaging system in a video camera can see the light extending past both ends of the visible light scale, which includes both infrared and ultraviolet. Since the infrared portion of the light spectrum is not visible to our eyes, the correct term for this portion of the spectrum is infrared radiation, not infrared light, but often both terms are used. The infrared portion of the light spectrum that can be seen by most video cameras covers the range of 700 nanometers well into 1500 nanometers, with exceptional sensitivity around 800 nanometers. Video cameras can also see ultraviolet radiation, but infrared radiation is easier to generate and at higher output levels will not cause any biological dangers like ultraviolet will. Not all video cameras will be able to see infrared light though, especially those designed for high quality color imaging. Camcorders and digital still cameras contain a glass filter that essentially blocks out all infrared light, leaving only the visible portion of the light spectrum so that the image quality is maintained. For this reason, camcorders will not be able to see the infrared light form an illumination system unless you are willing to open up the case and remove the tiny glass filter that has been affixed to the CCD imager. << Read more about this tutorial and other tutorials >>

Camera Trigger Hack

This external controller allows any device to control the shutter release There are times when you need to acquire a very high resolution image, triggered by some external event such as movement, time, or computer control. Video security cameras are very limited in resolution, often to less than 640 x 480 pixels, which in digital camera terms is less than half of one megapixel. Nowadays, a small digital camera that can take an image with a resolution of 4000 x 3000 pixels can be purchased for mere pocket change, so even if your subject is a long distance from the camera, the details will still be present in the image when zoomed on a computer screen. This simple project demonstrates how to hack into the camera's shutter release button to add some kind of external control to allow automated picture taking. Because this project is a hardware hack, you should not try this with a good camera, or one that you are worried about breaking. There is always a possibility of destruction when cracking the case open on such a small electronic device that is jammed full of tiny components. Of course, if you are good with small tools and a soldering iron, then this hack is fairly easy to do as long as you can find away to open the cover on your donor camera. Once completed, the resulting relay controller will allow any external electronic device to focus and then take a photo, essentially duplicating the operation of the two position shutter release trigger on your camera. Also, note that your camera will not be usable for regular photography after this hack as the original shutter release switch will be removed.

Figure 1 - This camera will be converted for external shutter control

The sacrificial camera shown in Figure 1 is an HP Photosmart M547 digital camera with an 8 megapixel imaging system. This camera has been around the world and dropped in an ocean, but despite some dents and scratches it still functions perfectly, so it will begin a new life as a covert spy gadget. To open one of these small digital cameras, you will need a set of tiny screwdrivers, a small knife and a whole lot of patience. Since the goal of manufacturing is to keep costs to a minimum, the cases on these cameras are often snapped together, which will require some careful prying to open them up. 

 

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