Archive for the ‘Light sensors’ Category

Light sensor (Part 2)

Part 1, 2 In the previous part of this publication, I covered the subject of sensitivity. As for many sensor, the range is very broad and a simple configuration cannot help covering the whole range of light intensities. As in the dated controllers, we might want to use a hand operated sensitivity selector. Although this […]

Light sensor (Part 1)

Part 1, 2 Sensing light is probably one of the most common sensing and probably one of the simplest measurement to start with. Light sensors are used to detect light or brightness in a manner similar to the human eye. They are most commonly found in industrial lighting, consumer electronics, and automotive systems, where they […]

I/O LED (Part 6)

Part 1, 2, 3, 4, 5, 6 Here is an amazingly simple and effective application that applies the photovoltaic properties of LEDs. Two identical extremly simple Arduino platforms are used. Each of them is fitted with a LED and a pushbuton. In idle mode, the LED is biased in photo sensing mode, waiting for potential signal. Each time the push […]

I/O LED (Part 5)

Part 1, 2, 3, 4, 5, 6 And now comes an example of an effective use of the I/O LEDs: single LED communication. the next coming  videos illustrate the operation of a simple but yet full of promises application. Two identical modules are used, each of them using an Arduino Nano, a LED and a switch. When pressing the switch, the sketch will […]

I/O LED (Part 4)

Part 1, 2, 3, 4, 5, 6 Here is a new version of the sensing LED. The sensing LED is turned on almost all the time, with very short periods of time during which it is biased as a photo LED. The measuring time is so short that it is almost impossible to observe the flickering effect. Approaching a source of […]

I/O LED (Part 3)

Part 1, 2, 3, 4, 5, 6 Additional works on I/O LED brought me to publish the next coming posts. Firstly, I observed that amongst the various LEDs tested from my stock, some were simply not suitable for I/O operation, while the high brightness red LEDs where performing optimally. Here is an illustration of the simplistic hardware that you may use […]

I/O LED (Part 2)

Part 1, 2, 3, 4, 5, 6 In the previous example, we observed the discharge time of the parasitc LED capacitance. In this way, LEDs can be used as light sensors. Let’s now see what we could do else when combining the emitting properties of the LED along with its sensing properties. In the next application, an LED will light up […]