A light meter is used to measure the intensity of illumination in a given area. It is widely used in schools, warehouses, factories, hospitals, office buildings, museums, art-galleries, parking garages, stadiums, and many more, to measure and maintain proper lighting levels. The intensity of illumination is usually expressed in Lux or foot-candles. As the 4th project in our chipKIT tutorial series, today we are going to build a digital light meter using the chipKIT Uno32 board and the BH1750 digital light sensor. This project uses Digilent’s chipKIT Basic I/O shield for displaying the measured light intensity in Lux, foot-candles, and Watts/m^2 units.
Digital light meter using chipKIT Uno32
I2C or IIC (Inter-Integrated Circuit) is a simple bidirectional serial interface, which requires only 2 signal lines for data transfer. It was originally developed by Philips in 1980′s to provide easy on-board communications between a CPU and various peripheral chips in a TV set. Today, it is widely used in varieties of embedded systems to connect many low speed peripherals, such as external EEPROMs, sensors, LCD drivers, port expanders, real-time clocks, etc, to the host microcontroller. In this tutorial, we will explore the chipKIT Wire Library for establishing an I2C communication link between the chipKIT Uno32 board and two I2C sensors. The Uno32 board receives the sensor outputs through the I2C link and displays the results on the serial monitor window on the computer screen.
I2C communication demo
This is a third project in our chipKIT tutorial series and today we are going to construct a simple pulse rate meter using our Easy Pulse sensor with Digilent’s chipKIT Uno32 board. Digilent’s chipKIT Basic I/O shield is also used in this project for displaying the pulse waveform and the pulse rate.
Pulse rate meter using chipKIT Uno32 and Easy Pulse
Pulse width modulation (PWM) is a technique of controlling the amount of power delivered to an electronic load using an on-off digital signal. The key idea behind this technique is that the average DC value of the digital signal, and hence the power delivered to the load, can be varied by varying the duty cycle of the signal. This method is commonly used for controlling speeds of DC motors and brightness of lamps. The switching mode power supplies are also based on the PWM technique. In this tutorial, we will discuss about the PWM pins of the chipKIT Uno32 board and illustrate the concept by controlling the brightness of two external LEDs.
This project is about building a PC-based temperature and relative humidity logger using the chipKIT Uno32 board and the DHT11 sensor. The project setup requires no additional wires (other than the USB cable) and components; the DHT11 sensor is directly plugged into four I/O pins of the Uno32 board and the project is ready to go. This could be a handy and an easiest way to setup an ambient room monitoring system for a server room. The Uno32 reads the temperature and relative humidity from the DHT11 sensor at preset interval and sends the data to PC through the USB-UART interface. A PC application is developed using the open-source Processing programming platform to log data onto an ASCII file. The PC application also displays the real-time temperature and relative humidity on computer screen.
PC-based logger for temperature and relative humidity