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Using the MSP-EXP430FG4618 Development Tool and the MSP430FG4618 device perform a frequency measurement.

Laboratory timers: lab5 - frequency measurement

Introduction

Correct system timing is a fundamental requirement for the proper operation of a real-time application. The timing definition can dictate how the data information processed during the execution of the application program. The clock implementations vary between devices in the MSP430 family. Each device provides different clock sources, controls and uses. This chapter discusses the clock controls included in the platforms used.

The MSP430 4xx family has two general-purpose 16-bit or 8-bit counters and event timers, named Timer_A, Timer_B, and a Basic Timer. The Basic Timer module is only implemented in ‘4xx devices. The 2xx device family also has Timer_A and Timer_B, but the clock signals are provided by the basic clock module+.

The timers may receive an internal or external clock. Timer_A and Timer_B also include multiple independent capture and compare blocks, with interrupt capabilities.

Overview

This laboratory implements an application ( Lab5_Timers.c ) designed to measure a PWM signal frequency. If a signal generator is not available, the microcontroller generates a PWM signal based on the frequencies stored in a file. The frequencies generated are read and updated with a fixed time period using the features of CCE . The measured value is shown on the LCD in Hz.

Resources

The module FLL+ is configured to a frequency of 7.995392 MHz for the MCLK and SMCLK clock signals. This application performs the two tasks simultaneously.

On the one hand, it generates a PWM signal with a frequency of 200 Hz and a duty cycle of 50%. Alternatively, the PWM signal frequency can be read from a file using a breakpoint. This function is performed by Timer_B, using the compare unit to generate the PWM signal.

The time period between two consecutive PWM signals low-to-high transitions is measured by Timer_A. The capture unit of this timer is configured to collect the Timer_A counter register’s contents when a PWM signal low-to-high transition is detected at its input.

The Basic Timer1 generates an interrupt once every second. The ISR updates the PWM signal frequency generated by the Timer_B. If you choose to use this feature, a breakpoint associated with this ISR execution allows reading a file with the value of the frequency that will be generated.

The microcontroller’s ports are configured in order that the PWM signal generated by Timer_B through the TBCCR4 compare unit available at Port P3.5/TB4 can be connected to the Port P1.2/TA1 of the Timer_A TACCR1 capture unit. If you plan to use this feature, these pins must be connected together. Port P3.5 pin is available on Header 7 pin 6, while the Port P1.2 pin is available on Header H2 pin 3.

Ports P2.1 and P2.2 are used to monitor the state of the LED2 and LED1, respectively.

The resources used by the application are:

- Timer_A;

- Timer_B;

- Basic Timer1;

- I/O ports;

- FLL+;

Questions & Answers

Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
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Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
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Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
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Damian Reply
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Cied
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I start with an easy one. carbon nanotubes woven into a long filament like a string
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Cesar
I'm interested in nanotube
Uday
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how did you get the value of 2000N.What calculations are needed to arrive at it
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Source:  OpenStax, Teaching and classroom laboratories based on the “ez430” and "experimenter's board" msp430 microcontroller platforms and code composer essentials. OpenStax CNX. May 19, 2009 Download for free at http://cnx.org/content/col10706/1.3
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