Page 184 - Making PIC Microcontroller Instruments and Controllers

TO THE EIGHT PBOJECIS
iAO A|{ II{TBODUCTIOI{

jn
The elecronic netronome is an exercisc creating accurate timeintervals that are
controlleal trom a potentiometer on both thc LAB-Xl boa1d and the tachometer boad.
The exercise includes programming for botl the LCD on the LAB-XI and for a dis-
play consisting of the 4 seven scgment LEDS used on the tachometer in the first

3. COU TING MARBLES! DlSCFlMlilAtlNG BETWEEN vAR'lflllc
PULSED SIGI{ALS AND FEEDING THE TIMER/COUIITERS
Part 1... Mr. Marblss the manager ol the local marble factory has been plagucd with
marble countirg problems and has approached the head ofthe electronics departnent
to see ifhe can come up with an inexpensivc solution. The class is chargcd with design
ing a marble counter that counts the marbles as they go by single file at the .ate of about
rcnmarble\persecond.JndlhclrclorymJnagcr\\dnl'lLrinclca\elhrlralea\mucha'
jn
possible. The counter that can count the highest number of marblcs 10 seconds accu-
ralely will be selected as the instrument of choice by the plant manager
jnfor-
This is aboutleaming how to count the pulses wc encounter when processing
mation, Some come in slow. some come in fast, some come in vely fast, and some are
hard to discrimioate fron the background noj se. This exercj se exposes you lo lhese real
world problems.
Part 2.-. Mr Marbles. our friend from the marble factory. is so happy wiih the per_
fomance of the counter we made for hi m edrlier that he has come back to us for an even
"Wha!
faster counter can you make in the way of a rcally fast counter?" he asks We
have convinced him that we can make him what he would consider a really fast counte!
but the marbles need to go by single filejust as they did for the previous counters. To
this he has agreed.
This insfument will count how many common everyday glass marbles go by its so
called gate. We are doing this just to do ill Someone mightjust have a use tbr this, or
a modified version of this, but our purpose here is to understand the detection, ampli-
ficadon. and the counling ofsmall seemingly rdndom signals coming in helter skelter'
In this experiment, things start to get complicated and wc have to use our wirs to figurc
out how we can sohJe the problems. So, in a way, this is an exposure to ihe reai world.

TWO AI{ALOG S|GI{ALS
4. rHE DUAL THERMOIITETER!
COI{VERIED TO DIGITAL AiID DISPLAYED
Dr. Thermo is in the piocess of undertaking a large research project to check the energy
transfer acrcss a large number ofcoils to be used in the air conditioning industy He
has indicated that he needs to know how the lemperature oI the air and the temperature
of the cooling brine changes as the heat exchange takes place. Design an instrument to
display the inlet tcmperalure and the outlet temperature for both fiuids
The instnment is an elecaodc themometer that re3ds two temperatures sinultareously
This is an i nstxmenl yoLr can use every day in your day to-day monitoring of the systems
amund vou. Each sensor costs about $3. This exercise is aboul reading analog signals,