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To learn what is involved in Analog to Digital Conversion.

Background questions

  • The ez430 has a 16 bit SD Converter. The number of bits used by the ADC is known as its resolution. What are the number of possible values that the 16 bit SD Converter can represent?
  • Extreme voltages, either too high or too low, cannot be measured correctly. What is the range of analog voltages that can be accurately represented on the ez430? You may want to check the User's Guide or experiment with the hardware.
  • In the real world, signals are polluted by "noise" that alters the quality of the original signal. Signal to Noise Ratio, SNR, is often used as a measure of the quality of a signal. Before a signal is sampled through the ADC, it is helpful to condition the signal in order to improve its SNR. What can be done to condition the signal? Where would it be ideal to condition it and why? (i.e. at the ADC, near the source, at the processor?)
  • The Nyquist Theorem states that a signal must be sampled at least twice as fast as the highest frequency in order to be decoded without error. The minimum sampling frequency is therefore known as the Nyquist Sampling Rate. Typical, audio CDs are sampled at a rate of 44.1 kHz, and can be decoded to 65,536 unique voltage levels. What is the highest frequency that can be represented without error? How many bits per sample are used? What is the total data rate for a stereo CD?

Adc setup

  • Figure out what the following codes is doing. Set up the hardware so that it functions correctly, and comment each line of code. What is the code's function? #include "msp430x20x3.h" void main(void) { WDTCTL |= WDTPW + WDTHOLD; DCOCTL = CALDCO_8MHZ; BCSCTL1 = CALBC1_8MHZ; P1DIR |= 0x01; SD16CTL |= SD16REFON + SD16SSEL_1; SD16INCTL0 |= SD16INCH_6; SD16CCTL0 |= SD16SC; while (1) { while ((SD16IV & SD16IFG)==0); if (SD16MEM6 >= 0xD6D8) P1OUT |= 0x01; else P1OUT &= ~0x01; _NOP(); } }
    Most modern compilers intended for use with embedded processors, such as the IAR Workbench , allow the user to check the status of the registers while the program is halted. This is extremely helpful in debugging code. For example, if the program is halted with a _NOP() after a sample is taken from the ADC, the user may check the SD16MEMx register (by setting a breakpoint at the _NOP() command) to see the new value that has been stored. If a value has changed since the last time the processor was halted, it will turn red in the watch window.
  • Create a version of the program that is completely interrupt driven. The original program uses a while-loop to poll for the interrupt flag. What is the sampling rate? Remember to put the processor into a low power mode and enable interrupts after configuring the SD Converter as discussed in Lab 5

Led dimmer

Add the file containing the LED dimmer function you wrote in Lab 4 to a new project in which you configure the SD Converter. Attach a Photo Diode (DigiKey# ********), a diode that outputs a voltage depending on the ammount of light that hits it, to any one of the SD16 inputs. Input the SD16MEMx value into the LED dimmer function in such a way that the LED's brigtness is indirectly propotional to the ammount of light that hits the Photo Diode. In other words, if we block the light to the diode, the LED should appear brighter; if we shine light on the diode, the LED should appear dimmer. If you do not have access to a Photo Diode, simply set the input to the integrated temperature sensor and perform the same exercise.

Flash storage

Now, chose any analog source (temperature sensor, Photo Diode, function generator etc.) on any input channel and store the values in flash using what you learned in Lab 6 . After a specific number (that you select) of samples are stored, have your program output the values using the printf with the help of a for or while loop. Then take the values and plot them on a graph. You may want to store every 10th (or 20th or 50th etc.) sample in flash to be able to see the analog signal over a longer period of time.

Questions & Answers

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
Do somebody tell me a best nano engineering book for beginners?
s. Reply
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
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
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
can nanotechnology change the direction of the face of the world
Prasenjit Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Introduction to the texas instruments ez430. OpenStax CNX. Jun 19, 2006 Download for free at http://cnx.org/content/col10354/1.6
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