The working principle behind a night vision device centres around the use of InfraRed (IR) LEDs. The light emitted by an IR LED, when boucned off of an object, can easily be seen by a camera. Human eye can only perceive visible light, not IR, or UV, or for that matter, any other form of light whose wavelength and frequency characteristics don’t overlap those of visible light. Following that, a grid comprising several IR LEDs mounted around a camera can effectively enable the camera to see in dark.
For our project for the “Microprocessor Programming and Interfacing” course this semester, we were advised by the instructor to work on designing and constructing a night vision device based on the same prinicple described earlier. It seemed all simple enough, until we actually sat down to work on it.
We spent two nights and three days, nearly, sleepless and restless, designing and constructing what we might proudly claim to be a night vision device in the end. On the d-day, we had something that could clearly see in the dark, but the additional features to be included with the main device were still dysfunctional, to some extent.
The IR LEDs are delicate. Their current ratings are high, while they start to burn off at any voltage greater than 3.0 volts at max. The IR LED grid we had constructed was built to work on 3 volts. Anything more than that for a length of time at a stretch, and the complete grid would go south.
The better half of the morning and afternoon on the d-day was spent working on functionalising the additional modules. They showed no hope of working. Frustrated, tired, sleepless, someone inadvertently supplied 5 volts across the IR LED grid. Boom! Kaput! The complete grid fried off — not literally, but that was what had happened. Some of us did not want to believe the grid had burned off, and kept on tweaking one thing after another in the hopes of somehow making the device work miraculously. It did not work. It was dead. The project was dead. And we were all ready to accept the consequences.
Only, the instructor, instead of penalising us with an upfront zero, offered us another chance to re-do the device and re-submit in a week’s time. Hard as it may be to believe, some of us cursed under our breaths at that. The drudgery had already been unbearable. And another week was going to add further fuel to the already ablaze fire.
Anywho, we packed up, gathered our equipment, and left off for our houses to get back on the lost sleep. Few of us got mildly sick from spending up nights and days without rest and much food. But, anyway, it all passed.
The better half of the next week was unproductive. We would gather up every evening after University at a friend’s place and ponder over our plans to re-do the project. Sadly, nothing productive came to pass, until, again, only the weekend was left.
We again spent two sleepless nights soldering circuit components and wrapping wires of different colours on circuit boards. From the way things were going, it seemed we were worse off that time than we had been the last time. However, on the d-day, what we had in our hands was a much better end product than it had been the last time.
With little additional tweakings, we were able to make the night vision device work nearly flawlessly. In whatever time we had before the demonstration, we were able to do the software part in assembly. Finally, we demonstrated the project and got off easily.