Compass Sensor with Microcontroller Project

INTERFACING AN ANALOG COMPASS TO AN EMBEDDEDCONTROLLER
AbstractThis paper describes the development of a compass sensing unit for use on a remotely operated vessel. The sensor determines the direction of the vessel’s path to aide the user in operating the boat wirelessly through a laptop. The system provides information tofacilitate tracking and controlling the boat when it is not easily seen by the operator. The selected compass, Dinsmore R1655 analog compass sensor, was used in conjunction ofan 8051 microcontroller to provide the necessary data. The system was able to read an analog value from the sensor and convert it to digital direction. The paper will describe the system design and present test results.

http://www.icee.usm.edu/icee/conferences/asee2007/

papers/630_INTERFACING_AN_ANALOG_COMPASS_TO_AN_EMBE.pdf

Microcontroller Design Final Project: Digital Compass
The goal of this project is to build a digital compass that displays both the direction and cardinal points on a television. Other functionalities were added to complement the sensor interface, such as, temperature display, magnetic declination input and disability option.

http://instruct1.cit.cornell.edu/courses/ee476/FinalProjects/s2004/ccw27/index.htm

Electronic Compass Design using KMZ51 and KMZ52
This paper describes how to realize electronic compass systems using the magnetoresistive sensors KMZ51 and KMZ52 from Philips Semiconductors. Therefore, firstly an introduction to the characteristics of the earth´s magnetic field is given. In the following, the main building blocks of an electronic compass are shown, which are two sensor elements for measuring the x- and y-components of the earth field in the horizontal plane, a signalconditioning unit and a direction determination unit.

Functional block diagram of an electronic compass

http://www.nxp.com/acrobat_download/applicationnotes/AN00022_COMPASS.pdf

Autocalibration of an Electronic Compass for Augmented Reality

Abstract

Electronic compass is often used to provide the absoluteheading reference for tracking the user’s head and handsin Virtual Reality (VR) and Augmented Reality (AR),especially for outdoor AR applications. However,compass is vulnerable to environment magnetismdisturbance. Existing compass calibration methodsrequire complex steps and true heading reference whichis often impossible to be obtained in outdoor ARapplications, and is useful only when compass is inhorizontal plane. An autocalibration method without theneed of heading reference and redundant sensors isproposed in this paper. First the compass error modelbased on physical principle is presented, then thealgorithm to calculate the compensation coefficients witha set of sample measurements of the sensors in thecompass is described. Because the influence of theenvironmental disturbance has been effectivelycompensated, the calibrated compass can providedaccurate heading even when it is under large tilt attitude.

http://csdl2.computer.org/comp/proceedings/ismar/2005/2459/00/24590182.pdf

3-AXIS COMPASS REFERENCE DESIGN with Microcontroller Circuit

The HMC1052 two-axis magnetic sensor contains two Anisotropic Magneto-Resistive (AMR) sensor elements in a singleMSOP-10 package. Each element is a full wheatstone bridge sensor that varies the resistance of the bridge magnetoresistorsin proportion to the vector magnetic field component on its sensitive axis. The two bridges on the HMC1052 areorientated orthogonal to each other so that a two-dimensional representation of an magnetic field can be measured. Thebridges have a common positive bridge power supply connection (Vb); and with all the bridge ground connections tiedtogether, form the complete two-axis magnetic sensor. Each bridge has about an 1100-ohm load resistance, so eachbridge will draw several milli-amperes of current from typical digital power supplies. The bridge output pins will present adifferential output voltage in proportion to the exposed magnetic field strength and the amount of voltage supply acrossthe bridge. Because the total earth’s magnetic field strengthis very small (~0.6 gauss), each bridge’s vector component ofthe earth’s field will even be smaller and yield only a couple milli-volts with nominal bridge supply values. Aninstrumentation amplifier circuit; to interface with the differential bridge outputs, and to amplify the sensor signal byhundreds of times, will then follow each bridge voltage output.

http://www.ssec.honeywell.com/magnetic/datasheets/hmc1055.pdf

Compass Sensor

Infrared Distance Sensor with the Microcontroller Project

Infrared and Ultrasonic Scanner
(ATMEGA32 microcontroller)

This project is a short range, infrared and ultrasonic
scanner that uses a standard hobby servo to move the
sensors and a color LCD screen to display the information
from the distance sensors. The information displayed
on the LCD is an overhead view of the scanning area,
with increments of distance from the distance sensors.

Hardware Details:
The core of the project is the ATMEGA32 microcontroller
from Atmel. It controls the servo, gathers information from
the sensors and places the information on the LCD screen.
There is 32K of flash in the microcontroller and the software
uses about 13K of that. Since the LCD uses a maximum of
3.3V, the microcontroller is run at 3.3V.
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Interfacing the GP2D02 to a Microcontroller PIC and
Sweeping it with a Hobby Servo

The Sharp GP2D02 is a sensitive compact distance measuring
sensor. It required two lines from a microcontroller in order to be
controlled. One line provides the signal to begin a measurement
and also is used to provide a clock signal when transmitting the
distance measure, and the other line is used to transmit the
measurements back to the microcontroller. I interfaced the GP2D02
to a 12CE519 microcontroller rather than my main CPU (16C77) in
order to free up processing time on the 16C77. The GP2D02 requires
an open collector on its input line, so I connected it through a diode
to the 12CE519. The GP2D02 output is connected directly to the
12CE519. As I was limited to one GP2D02 IR sensor per robot,
I used a hobby servo motor to sweep the GP2D02 through a 50
degree pattern in the front of the robot. The servo used was a
Cirrus CS-70 Standard Pro Servo.

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The MBasic Compiler - DISTANCE SENSORS
TYPES OF DISTANCE MEASURING DEVICES

There are many different types of technologies and devices
used in measuring distance, some of them being: Radar, Sonar,
Laser, Infrared and Ultrasonic. In this chapter Infrared and
Ultrasonic will be covered. Infrared uses light that is invisible to
the human eye. Also Infrared light bounces off almost everything.
Its main disadvantage is that fluorescent lights generate it and that
can cause interference. Ultrasonic uses sound that is inaudible to
the human ear. Its main advantage is that it is not sensitive to objects
of different colors and light reflecting properties. Its disadvantage
is that some materials absorb sound and don’t reflect it.


PROJECT_6
The components used in this project are one Sharp GP2D12
Infrared distance sensors, one Ultrasonic circuit, a buzzer, a rotary
switch circuit (refer to schematic from Project_5) also the parts from
Project_4. Fifteen of the twenty-two I/O pins of the PIC16F876 will
be used in this project.

more pdf

Distance Sensor

Ultrasonic Distance Sensor with the Microcontroller Project

Accurate Ultrasonic Distance Measurement Project

Abstract - This paper introduces a different approach to
the measurement of the time-of-flight of ultrasonic signals.
Frequency variation monitoring and recording is used to
determine accurately the arrival time of the ultrasonic signal.
A high speed Digital Signal Processor (D.S.P.) is used for
both: transmission and direct measurement of the frequency
of the incoming signal in every single period and with an
accuracy of about 0.1%. The proposed configuration offers
small size and low cost solution to displacement
measurements with a remarkable performance in terms of
accuracy, range and measurement time.

THE SYSTEM
The configuration of the proposed system is based on the
capabilities of accurate time measurement of modern microcontrollers.
The usual series of microcontrollers can not be
used in this application mainly because of their relatively
low frequency of operation (clock frequency) which affects
the accuracy of time measurement within one single period.
They can not offer the required fast and accurate frequency
measurement. A high performance system may therefore be
built only on a more powerful microcontroller. Larger
systems (personal computer type, etc) are avoided for
practical reasons; the overall measurement system should be
cost-effective and small sized.

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Ultrasonic Distance Sensor Implemented
with the Microcontroller Project
Linear measurement is a problem that a lot of
applications in the industrial and consumer market
segment have to contend with. Ultrasonic technology is
one of the solutions used by the industry. However, an
optimized balance between cost and features are a must
for almost all target applications. The ultrasonic distance
measurer (UDM) is used mainly when a non-contact
measurer is required. This is the type of solution this
document explains using a simple robot toy
implementation.

Description
The UDM is a demo that shows capability and performance
of the MC9RS08KA2 and the ultrasonic sensor to build a
distance measurer. Figure 2 shows the basic building block of
this project.

The firmware generates a 40 kHz burst signal. After the 10 cycle
burst is completed, a variable that measures the distance is
activated. This variable measures the time sound takes to rebound
and is used for distance calculation.

The burst signal goes to the ultrasonic transmitter (US Tx) and is
transmitted as ultrasound through the air Figure 2. When the wave
is reflected off an object, this wave is captured by the ultrasonic
receiver (US Rx.) This received signal is amplified because it
attenuates as it travels. Afterwards, the signal goes back to the
microcontroller unit (MCU), filters it and calculates the distance.
A 40 kHz interrupt is generated by the timer in the MCU. To
perform this, the keyboard interrupt (KBI) is enabled and detects
the external signal. Every time the MCU is interrupted the counter
is increased by three. And the variable used as a counter is
decreased by one for the entrances to the modulus timer module
(MTIM) interrupt service routine (ISR). When this variable is bigger
than eight the ECHO signal is activated. The distance variable is then
set to 0. Refer to Figure 3 for timing diagram. For detailed information
about the firmware see Figure 3.

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Distance Sensor

Digital Light Sensor to MICROCONTROLLER Circuit

ISL29001

The ISL29001 is an integrated ambient light sensor with
ADC and I2C interface. With a spectral sensitivity curve
matched to that of the human eye, the ISL29001 provides
15-bit effective resolution while rejecting 50Hz and 60Hz
flicker caused by artificial light sources.
In normal operation, the ISL29001 consumes less than
300µA of supply current. A software power-down mode
controlled via the I2C interface disables all but the I2C
interface. A power-down pin is also provided, which reduces
power consumption to less than 1µA.
The ISL29001 includes an internal oscillator, which provides
100ms automatic integration periods, or can be externally
timed by I2C commands. Both the internal timing and the
illuminance resolution can be adjusted with an external
resistor.

ISL29001 datasheet pdf


Microcontroller Advanced Kit - Light Sensor Project

This tutorial shows how to set up a microcontroller based
system that converts a signal from a light sensor to a 6 bit
digital value. This value can be used by the microcontroller,
perhaps for a robotic controller, or as in this tutorial, sent to
the PC. It uses the AT89C2051 microcontroller to collect
data and send it to the PC. A MAX232CPE chip is used to
convert the signals from and to RS232 levels for sending
and receiving through the serial port. The 2051 microcontroller
has a built in analog comparator that is used to make a
simple analog to digital converter to convert the light sensor
output to a digital value.

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