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TACTL = TASSEL_2 |MC_2 | ID_0 | TAIE; // SMCLK // up mode to 0xFFFF

The capture unit captures the TAR register value to the TACCR1 register when it detects a low-to-high transition at the TA1 input. What is the value to write to the configuration register?

TACCTL1 = CCIS_0 | CAP | CCIE; // Capture on rising edge,// TACCR1 input signal selected, // Capture mode,// Capture/compare interrupt enable.

Determine the maximum and minimum frequency values detected. Note that these values do not take into account the execution time of the application. The PWM signals should be applied at frequencies well below the maximum value determined.

Maximum frequency value: ____________

Minimum frequency value: _____________

The TACCR1 capture unit is configured to generate an interrupt when it detects a low-to-high transition. What is the value to write to the configuration register?

TACCTL1 |= CM1

Ports p3.5/tb4 and p1.2/ta1 configuration

These ports perform special functions. Thus, the Port P3.5 is configured as an output, selected by the special function TB4, with the values:

// TB4 configuration (Port3) P3SEL = 0x20; // P3.5 as special function (TB4)P3DIR = 0x20; // P3.5 as output

The Port P1.2 is configured as input, with the special function TA1, using the values:

// TA1 (TACCR1) configuration (Port1) P1SEL = 0x04; // P1.2 as special function (TA1)P1DIR = 0x00; // P1.2 as input

I/o ports configuration:

// SW1 and SW2 configuration (Port1) P1SEL&= 0x00; // P1.0 and P1.2 I/O P1DIR&= 0x00; // P1.0 and P1.2 as inputs P1IFG = 0x00;P1IES&= 0xFF // high-to-low transition interrupt P1IE |= 0xFF; // enable port interrupts// LED1 and LED2 configuration (Port2):P2DIR |= 0x06; // P2.2 and P2.1 as outputs P2OUT = 0x04; // LED1 on and LED2 off// Buzzer port configuration (Port3)P3SEL |= 0x20; // P3.5 as special function P3DIR |= 0x20; // P3.5 as digital output

Analysis of operation

Run the application using the frequency generator based on timer_b

Without a frequency generator, the Timer_B generates a PWM signal at the TBCCR4 unit output that can be fed back to Timer_A TACCR1 capture unit input. These two pins must therefore be connected together. By default, the PWM signal frequency is 200 Hz. Add a breakpoint at the line of code belonging to the Basic Timer1 ISR to modify this value.

TBCCR0 = 7995392/read_data;

If the variable read_data has the value 200, it will generate a 200 Hz frequency. The value of this variable can be changed by associating a breakpoint to that line of code. Before the line of code is executed, the value of the data file is read and assigned to the variable read_data . The signal will oscillate at the desired frequency, loading the value in TBCCR0. The breakpoint configuration is as follows:

- Action: read data from file

- File: address of the data file (example in freq.txt)

- Wrap Around: activate this option to restart reading at the beginning

- Start address:&read_data

- Length: 1 in order to read a value from the file each time

Run the application using a frequency generator

The operation of the application can be verified using a frequency generator. The generator should generate a PWM signal with voltage and frequency values compatible with the device’s input (2.5 to 3.3 volts).

Observe the measured frequency

The PWM signal applied to the TA1 input can be viewed using an oscilloscope, connected to pin 3 of Header 2. Perform this task and confirm the values present at the LCD.

Measurement of electrical current drawn

The power consumption was discussed in the previous point. The electrical power required by the system during operation is measured by replacing the jumper on the Header PWR1 by an ammeter, which indicates the electric current taken by device during operation.

What is the value read? __________

This example and many others are available on the MSP430 Teaching ROM.

Request this ROM, and our other Teaching Materials here (External Link)

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
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
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
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
what is fullerene does it is used to make bukky balls
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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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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