Light intensity and other environmental parameters With Xmega AVR
Here is little project, which in the next once proves the superiority an Xmega AVR microcontroller on monitoring and controlling process.
This project was designed to control and monitoring the environmental conditions that includes a set of sensors for measuring Light intensity temperature and humidity. XMEGA16A4 Microcontroller is used in this project.
The XMEGA A4 is a family of low power, high performance and peripheral rich CMOS 8/16-bit microcontrollers based on the AVR® enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the XMEGA A4 achieves throughputs approaching 1 Million Instructions Per Second (MIPS) per MHz allowing the system designer to optimize power consumption versus processing speed.
The XMEGA A4 devices provides the following features: In-System Programmable Flash with Read-While-Write capabilities, Internal EEPROM and SRAM, four-channel DMA Controller, eight-channel Event System, Programmable Multi-level Interrupt Controller, 36 general purpose I/O lines, 16-bit Real Time Counter (RTC), five flexible 16-bit Timer/Counters with compare modes and PWM, five USARTs, two Two Wire Serial Interfaces (TWIs), two Serial Peripheral Interfaces (SPIs), AES and DES crypto engine, one Twelve-channel, 12-bit ADC with optional differential input with programmable gain, one Two-channel, 12-bit DAC, two analog comparators with window mode, programmable Watchdog Timer with separate Internal Oscillator, accurate internal oscillators with PLL and prescaler and programmable Brown-Out Detection. The Program and Debug Interface (PDI), a fast 2-pin interface for programming and debugging, is available.
The TSL230R, TSL230AR, and TSL230BR programmable light-to-frequency converters combine a configurable silicon photodiode and a current-to-frequency converter on single monolithic CMOS integrated circuits. The output can be either a pulse train or a square wave (50% duty cycle) with frequency directly proportional to light intensity. Device sensitivity is selectable in three ranges, providing two decades of adjustment. The full-scale output frequency can be scaled by one of four preset values. All inputs and the output are TTL compatible, allowing direct two-way communication with a microcontroller for programming and output interface. An output enable (OE) is provided that places the output in the high-impedance state for multiple-unit sharing of a microcontroller input line. The devices are available with absolute-output-frequency tolerances of 5% (TSL230BR), 10% (TSL230AR), or 20% (TSL230R). They have been temperature compensated for the ultraviolet-to-visible light range of 320 nm to 700 nm and respond over the light range of 320 nm to 1050 nm. The devices are characterized over the temperature range of –25°C to 70°C.
The HIH-4000 Series Humidity Sensors are designed specifically for high volume OEM (Original Equipment Manufacturer) users. Direct input to a controller or other device is made possible by this sensor’s linear voltage output. With a typical current draw of only 200 µA, the HIH-4000 Series is often ideally suited for low drain, battery operated systems. the RH sensor is a laser trimmed, thermoset polymer capacitive sensing element with on-chip integrated signal conditioning. The sensing element's multilayer construction provides excellent resistance to most application hazards such as wetting, dust, dirt, oils and common environmental chemicals.
The LM35 series are precision integrated-circuit temperature sensors, whose output voltage is linearly proportional to the Celsius (Centigrade) temperature. The LM35 thus has an advantage over linear temperature sensors calibrated in ° Kelvin, as the user is not required to subtract a large constant voltage from its output to obtain convenient Centigrade scaling. The LM35 does not require any external calibration or trimming to provide typical accuracies of ±1⁄4°C at room temperature and ±3⁄4°C over a full −55 to +150°C temperature range.
- Calibrated directly in ° Celsius (Centigrade)
- Linear + 10.0 mV/°C scale factor
- 0.5°C accuracy guaranteeable (at +25°C)
- Rated for full −55° to +150°C range
- Suitable for remote applications
- Low cost due to wafer-level trimming
- Operates from 4 to 30 volts
- Less than 60 μA current drain
- Low self-heating, 0.08°C in still air
- Nonlinearity only ±1⁄4°C typical
- Low impedance output, 0.1 W for 1 mA load