LM75A is a digital temperature sensor with built in analog to digital converter and I2C interface .It can provide an accurate temperature reading from -55 to +125 C. For similar design based on analog LM35 sensor click here. Also a version based on DH11 humidity and temperature sensor is available at this link. In this … Read more
Generating sound patterns with Arduino is a topic of this article. All you need is Arduino compatible board a simple DC buzzer and current limiting resistor. In this project I’ll show how to build a police siren using Arduino Mega or UNO boards. The schematic is shown next. 3 push buttons for selecting a desired … Read more
Current LED Bar Graph design for Arduino UNO platform uses 16 independently controlled RGB LED’s with integrated WS2812 chip. Similar project is available at this link. In general the voltage is divided into equal intervals equal to the number of LED’s being used . As the input voltage rises the color and the number of … Read more
LED Battery Level Indicator can be built using Arduino UNO board and 10 LEDs. Similar design that uses 2×16 LCD display can be found at this link. RGB LED variant is here. For Raspberry Pi version click here. I/O lines are directly driving 10 colored LEDs (4 – Green, 2 – Yellow, 2 – Orange … Read more
A simple light sensor can be built using a photoresistor and Arduino UNO board. Similar design is available here. This design requires only a few additional components like 10k resistor and a 10k potentiometer to adjust the light intensity level to trigger the circuit. Photo resistor in series with 10k creates a simple voltage divider … Read more