# 7.2 7.3 - lab 7: the adc

 Page 1 / 1
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?

• 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.

how do they get the third part x = (32)5/4
can someone help me with some logarithmic and exponential equations.
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
I don't understand what the A with approx sign and the boxed x mean
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
oops. ignore that.
so you not have an equal sign anywhere in the original equation?
Commplementary angles
hello
Sherica
im all ears I need to learn
Sherica
right! what he said ⤴⤴⤴
Tamia
hii
Uday
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
a perfect square v²+2v+_
kkk nice
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
rolling four fair dice and getting an even number an all four dice
Kristine 2*2*2=8
Differences Between Laspeyres and Paasche Indices
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
is it 3×y ?
J, combine like terms 7x-4y
how do you translate this in Algebraic Expressions
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
what's the easiest and fastest way to the synthesize AgNP?
China
Cied
types of nano material
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.
what is nano technology
what is system testing?
preparation of nanomaterial
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
what is system testing
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
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
how did you get the value of 2000N.What calculations are needed to arrive at it
Privacy Information Security Software Version 1.1a
Good
Got questions? Join the online conversation and get instant answers!