Use this project to
burn your own chips for:
PIC DICE
XXXX
Build Logic Probe/Pulser (slimline)
$8.00 kit,
to check the operation of the
add-on circuits you design.
You will also need:
- PIC Burner Board.
We will not be using the pins at the top of the
PCB but burning the chip on the PIC Burner PCB
and transferring it to the project.
You will learn:
- PIC micro programming
- Design and build interface stages for input
and output devices
- Build and use a Logic Probe to test
circuit operation
- "Burn" (flash) (program) PIC chips using
onboard ICSP pins
- Build additional projects using PIC micro's
- Get $1,000 worth of electronics skill for
$50.00 !!! |
"PIC Fx-1" is a
DEVELOPMENT PLATFORM - a Prototyping Module.
It's a small board containing an 8-pin microcontroller and a matrix area
for experiments.
$12.00
It's very similar to the original BASIC stamp-1, developed in about 1993 to
get beginners into the world of programming.
The experimental section had no supply rails and a very awkward
matrix-layout. A matrix layout needs to be long and thin as that is the
way a circuit extends. There was no on-off switch and you had to
constantly clip the battery to the battery-snap. My BASIC Stamp remained
in pristine condition because it came with no components for
experimenting and "did-nothing" when turned ON. On top of this I very
soon realised the programming had nothing to do with PIC
microcontrollers.
$30.00
We have taken the concept and made it even simpler by
providing "cut-and-paste" sub-routines and removed the need to learn a
programming language.
The end result is more value for your money with a much-simpler approach
to programming. And your program can be about 4 times larger.
The BASIC Stamp came "empty" and you had to download programs to
see any results. PIC Fx-1 comes with 4 main PROGRAMS for the 3 input switches
and 3 output LEDs.
You can see what can be done with a micro as soon as you assemble the
kit. The second part of this article teaches you how to produce a program by
cutting and pasting sub-routines into a template.
This is how you create a program. You
actually use the instructions needed by the micro (not a
programming language called a "high-level language"). Only 35
instructions are needed for the micro and they are provided in a single-page layout,
for easy access.
You regularly use only about 20 of these and they are in
the "cut-and-paste" code you take from other programs and also
from the LIBRARY OF ROUTINES.
In most cases you go to a project and take the code that performs the
function you require.
You place it in the sub-routine area of the template and CALL it from
the MAIN routine.
Once your program is complete, it is "burnt" or "flashed" into the
memory of the micro (called the program memory section) via a programmer
(called USB Programmer) using the In-Circuit programming pins
at the top of the board.
This will erase the
programs supplied in the chip, so additional chips are recommended if
you want to write your own
programs.
The chip on the board comes fully programmed with the LED Fx-3 program
(with more
than 10 effects), plus 3
extra programs:
Code Lock, Reaction Timer and 4-Alarm Sounds.
The 10 effects on the 3 LEDs include flashing, dimming and random
flickering and you can
produce your own sequence on the LEDs and store it. All these program
use only 65% of the memory. That's how much you can get into a very
small microcontroller. Only one of these program would fit into the
BASIC Stamp due to the micro being filled without routines that are not
needed and you program had to be fitted into an external chip that was
limited to a maximum of about 80 instructions. Our 4 programs require
about 600 instructions.
You cannot compare the two via the number of instructions as
the BASIC Stamp can multiply an instruction to between 2 and
20 PIC instructions. However the BASIC Stamp may take 2 to
4 locations to hold an instruction (and up to 10 locations). So, the BASIC Stamp-1 runs
out of programming capability very quickly and in the past 20 years we have only seen
very small projects using it. That's why they upgraded their range to
much larger PIC chips.
But our aim is not to compare or contrast our concept with any of
the other modules on the market as they are fulfilling a need to get a
simple project up-and-running via a micro.
We are showing HOW to PROGRAM, How the Micro Works and how
1,024 lines of code (instructions) can be used to produce very impressive projects.
Go to P2 for: "learning to write your own programs."
It has a set of experiments to teach PIC
programming - starting with
flashing a LED.
The CIRCUIT
The circuit is very simple. It is
just a micro, 3 LEDs and 3 switches. All the work is done by the micro.
We have added a 5v regulator so the project can be connected
to any voltage from 7v to 15v.
It will work on 6v if the regulator is removed and a diode is placed between
the "in" and "out" pads or on 7v to 15v
DC with the regulator fitted to the board.
This makes it suitable for a 9v battery or the DC supply from a model
railway.
The 5 In-Circuit Programming pins allow you to program the chip
while it is in-circuit.
PIC Fx-1 PCB
The Matrix section is 21 holes
x 10 holes
The matrix section is longer than shown and provides
plenty of space to add components and design your own interface stages
to drive motors, LCD displays, servo's, piezo's etc.
Driving many of the output devices have already been covered in other projects,
so you don't have to "re-invent the wheel." You just copy the
required instructions into your own program.
The Complete PIC FX-1 Project.
The top and bottom lands are positive and negative rails
These pins are not used - the project has been updated
and we now use the PIC Burner board and transfer the chip
after it has been burnt
to USB Programmer |
to 9v battery |
This connector-board is not used
- We now use the PIC Burner module
|
CONSTRUCTION
Build the project on the PC board
provided in the kit. All the components are supplied, including parts
for the experiments.
There are two things to note.
The 100u electrolytic is replaced with a 10u tantalum soldered under the
board. The lands can just be seen at the edges of the component and by
tinning the pads first and using a little fresh solder, the tantalum
will solder very nicely to the pads. The other item to note is the link
to pin-1 of the micro. This track is missing from the board and must
be connected via a short length of fine tinned copper wire (included in
the kit). The 5 programming pins are called "machine pins" and are
soldered directly to the top of each land by adding a little solder to
the land and the hollow end of the pin.
To make soldering these pins in place, insert a pin into the end-pin on
the 5-pin connector and use it to place the pin onto the land you have
just added a small amount of solder to. Heat the pin and it will be
soldered in place. Remove the 5-pin connector and add another pin to it.
Re-connect the 5-pin connector and locate the next pin to the pre-tinned
land. Solder it in place.
Repeat until all 5 pins have been added to the board.
SURFACE-MOUNT COMPONENTS
To make the PC board as small as
possible, we have used surface-mount components. You will need fine tweezers to hold them in place while
one end is soldered.
Always use very fine solder (as supplied in the kit) as you only need very little for each
component and the main reason for adding extra is to take advantage of
the flux to clean the connection. Always solder the SM resistors with the value
showing.
PIC Fx Modification
Turn the PC board over and connect the middle 47k and the end 47k
surface mount resistors to the 22k resistor as shown in the image.
The surface mount
components are clearly identified
820 on chip = 82 and no zero's
223 = 22 + 000 = 22,000 ohms
4702 = 47 + 0 + 00 = 4700 ohms THE LEDs
The LEDs supplied in the kit are high-bright 3mm white LEDs that take less than
17mA to achieve full brightness. You can change them for other
colours to suit your own
application. The 82R dropper resistors will have to be increased to 220R
(221 on a chip resistor) for any other colour.
TESTING
When you have constructed the project, you can
tests its features:
Turn the project ON and the LEDs will “chase.”
Turn the project OFF and push button A and keep it pressed while you
turn the project ON. Now press button A 3 times and each time the LED
will illuminate. Now stop and wait. The LED will flash 3 times.
Turn the project OFF and push button A and keep it pressed while you
turn the project ON. Now press button B once and wait. The middle LED
will flash.
Now do the same will all sorts of button sequences (up to 15) and see
how the project responds.
Keep the micro and use another micro for your experimenting.
THE PROGRAMS
The 3 programs contained in the chips that comes with the kit of parts
has a single program with sub-routines for the 3 programs.
The micro starts in the Set-Up routine and looks for the press of button
A, B or C to go to the required section of the program.
If NO button is pressed, the micro goes to LED Fx-3 routine.
This allows four separate projects to be included in a single chip. This
concept is very handy for a programmer to be able to get into a program
(after installation) and change data values. The data values are stored
in EEPROM - more on this concept, later.
LED Fx-3
This program produces a number of flashing
LED effects and can be set so that any of the sequences will show when the
module is first turned on.
It uses about 400 instructions to produce the effects and the EEPROM is
used to store the sequence
produced by the user (sequence 1) - and show it at turn-on.
Here are the instructions:
INSTRUCTIONS FOR USE
There are 12 sequences.
The first sequence can be created by the user. It currently produces a
very slow flash-rate as it has not be programmed. The other 11 sequences
are pre-programmed.
Turn project ON.
Allow all the LEDs to flash two times
then push the first button (called SwA) and hold it down and the sequence will change
to the next sequence.
Release the button and allow the sequence to cycle.
Push SwA again and the sequence will change.
You need to allow each sequence to cycle with the button not-pressed and then push SwA and keep it pressed until
a new sequence shows. This is due to the debouncing in the program.
TO CREATE YOU OWN SEQUENCE.
1. Press SwA
and at the same time, turn project ON.
2. Release SwA and press the switches in any order (up to 15 steps).
A step or delay cannot be longer than 2 seconds as the program will
"time out." When finished, wait 3 seconds and the sequence will show on
the LEDs.
3. Turn project off and on. The new sequence will appear as the first
sequence.
TO MAKE ANY SEQUENCE THE FIRST SEQUENCE
Any of the sequences can be saved as the first
sequence, as follows:
1. Turn the project ON and increment the sequences.
2. To save the desired sequence, press SwB. The display will die.
3. Turn project OFF then ON. The desired sequence will show at
start-up.
4. To delete this feature, push SwC and at the same time, turn project
ON.
|
CODE LOCK
This program is contained in the PIC Fx chip.
It is accessed by turning the project OFF.
Now press the first button.
Turn the project ON.
The first LED will flash to indicate the CODE LOCK program is accessed.
To open the "VAULT" you have to press the three buttons in a particular
order.
This project is ideal for a DOOR LOCK.
Normally the code will freeze after 5 attempts, but we have removed this
feature to see if you can "break the code."
The answer to the code is revealed at the bottom of this page.
REACTION TIMER
This program is contained in the PIC Fx chip.
It is accessed by turning the project OFF.
Now press the second button and keep it pressed.
Turn the project ON.
The second LED will flash to indicate the REACTION TIMER program is
accessed.
This program will test your reaction time.
Press the first button and the first LED will come ON.
Keep the button pressed.
The first LED will remain ON an unknown period of time and when it
extinguishes, you must release the first button and press the
third button (with the same finger).
The middle LED will flash to indicate tenths of a second.
4
ALARM SOUNDS
This program is contained in the PIC Fx chip.
It is accessed by turning the project OFF.
Now press the third button and keep it pressed.
Turn the project ON.
The third LED will flash to indicate the 4 ALARM SOUNDS program is
accessed.
Press the first button to access the first sound. Press the button again
for the second, third and fourth sound.
THE PIC12F6299
The PIC12F629 is
one of the smallest microcontrollers in the series that has enormous
capability.
The smaller devices are very limited and cost about the same.
The chip has 8 pins.
Two pins are for the 0v and 5v connections. The 5v must not go above
5.5v and can be as low as 3v, but it is best to keep the supply at 5v.
A 100n should be placed next to the chip across the supply rails to make
sure the chip works. The chip likes "tight" power rails and the 100n
does this.
The chip has an inbuilt 4MHz oscillator and this is divided by 4 so it
executes instructions at the rate of one million per second. Each
instruction takes one microsecond.
When an instruction tells the micro to go to another part of the
program, it takes two cycles (2uS) - called Machine Cycles. This is a
skip, goto, call, or return.
The other 6 pins are input/output lines and these can be changed at any
time during the running of the program.
The only thing to remember is pin 4 (General Purpose Input / Output)
gpio,3 is INPUT ONLY. If you try to make it an output, nothing
happens !
You can make any combination of pins "inputs or outputs" and this can be
changed during the running of a program.
The pins have 3-states called TRI-STATE. Any pin can be HIGH or LOW and
when it is configured as an input, it is HIGH IMPEDANCE. In other words
it is not connected to anything.
An output pin can deliver up to 25mA and this is called SOURCING.
This is enough to illuminate a LED and the white LEDs we have provided
in the kit are too bright to look at.
When a
pin is LOW it can sink about 25mA.
That's all you need to know to get started.
HISTORY
Let's go back and see how the microcontroller prototyping
module started.
It started with Parallax producing a small board with a PIC chip and
prototyping area in about 1993. The module cost about $50.00 (with a
very large manual) and used a
PIC16C56.
BASIC Stamp-1 (1993)
This is a one-time
programmable device with one full port of 8 in-out lines and a half-port
of 4 lines.
However the 4 lines of the half-port are taken up with connections to
the 93LC56 (246 byte EEPROM) to store data and your program instructions and the In-circuit
Programming pins. This leaves the 8-line full-port for experimenting.
The BASIC Stamp-1 has 256 bytes of program storage inside the 93LC56 and this is enough for 80 to 100
lines of PBASIC1 code. The PIC12F629 has this feature INSIDE the chip
and that's why the extra chip is not needed for the PIC Fx-1 module.
None of the code you produce is placed in the normal programming section
of the chip. This area is already taken up by Parallax's set of
sub-routines and these routines are accessed by a code written by you
and stored in the 93LC56 EEPROM.
This is like buying a diary and having it filled with examples of how to
writes stories, essays and poems, and providing 20 pages in a folder,
tacked on the the back of the diary, for
your own work.
All the unused sub-routines should have been left on your computer and
only those needed downloaded into the chip.
But to prevent anyone accessing the sub-routines, it has been contained
within the chip and the CODE PROTECT 'bit" activated so the chip cannot
be read.
This just leaves the 93LC56 EEPROM for you to use. The instructions
written by you are called PBASIC instructions and they take a variable amount of space
in the 93LC56
EEPROM. They vary due to the
complexities of the command and the type of arguments you supply. Generally, each
command takes 2 to 4 bytes of memory space, however, commands like SERIN,
SEROUT, LOOKUP and
LOOKDOWN, which accept a variable length list of arguments, may take
tens of bytes or more.
It is difficult to equate this to lines of ASSEMBLY CODE, when you are
programming the micro via the set of 56 instructions that come with the
chip, as some PBASIC instructions will be equal to 3 lines of assembly code and
others will be equal to more than 20 lines in a sub-routine.
But the main reason I did not use the module, and kept it in pristine
condition for the past 20 years was due to the fact that programming the
chip in BASIC had nothing to do with a PIC MICROCONTROLLER.
Any project developed on the BASIC Stamp-1 could not be transferred to a
PIC chip as a .hex file and this made the project very expensive.
Since the PIC chip we are using costs less than $2.00 and holds a program of 1,023
instructions, it seems only sensible to develop a Prototyping Module
using the smallest PIC chip in the series and show what can be done.
The underlying approach of Talking Electronics is to present simple
projects to get everyone STARTED.
The only way to achieve this is to lay everything out and explain things
in the finest detail.
It's no-good including complex words, involved terms or phrases that
need a Philadelphia lawyer to interpret.
The BASIC Stamp-1 comes "empty," whereas the PIC Fx-1 modules comes
"full."
It has 4 projects already "burnt" into the PROGRAM SPACE and all you have
to do is build the project, connect a battery and turn it ON.
It will immediately come ON with LED Fx-3 program and by pressing
buttons A, B or C before turning the project ON, you will be able to
access the Code Lock, Reaction Timer or 4-Alarm
Sounds.
Once you see how much can be fitted into this tiny chip, you will see
why we started with such a small device. It's the place to start.
PIC Fx-1 module can duplicate almost all the projects designed
for
the Basic Stamp-1 that use up to 6 in-out lines. But compare
the cost: (about $30.00 for the Basic Stamp-1 module plus $18.00 postage to $12.00 for the
PIC Fx-1 Module, plus $6.50 postage from Talking Electronics).
The 4 projects that come with the PIC Fx-1 Module could NOT be
fitted in the Basic Stamp-1 because there are over 500
instructions and the Basic Stamp-1 only has room for about 100.
That's what limits the Basic Stamp-1. Most of the programs
in the Stamp Manual and those submitted by readers have been very simple and equate to less than 300
lines of code in an ASSEMBLY PROGRAM.
There is one advantage of using
assembly.
As you increase the size of a program, you will be able to use some of
the previous sub-routines and this will allow you to do a lot more with
just a few lines of additional code, as you reach the end of memory. All
the programs in the
PIC Fx micro only occupy 664 locations, leaving about 360
locations (lines - instructions - for another program).
When you write a program in assembly, you are aware of the timing for
each of the routines and understand what each line is doing. You are
ACTUALLY programming and not writing an entry into your diary by writing
the words MY DOG and having the book look up the pages of pre-written
text
on the features of MY DOG, to explain what is meant.
No-one has thought of our copy-and-paste technique and that's why they
came up with the Basic Stamp-1 concept.
Not only is our concept simpler, but you don't have to learn any
language, and you get the full capability of the chip.
Overall, our approach will achieve two things.
It will get a new group of beginners into the world of microcontrollers
at very low cost and show how to produce a program to do almost anything
you want.
Once you get into microcontrollers, you will NEVER go back to complex
discrete componentry.
The PIC Fx-1 Module can replace more than 12 individual chips, as proven
by the programs it contains when purchased.
Don't be put-off by the small size. It has 3 inputs and 3 outputs. These
can be changed, but to keep things simple, it is best to keep to
projects having-up to this requirement.
The main idea is to duplicate projects you have seen in publications and
think of your own ideas. You can program the module to carry out these
tasks and cut the prototyping area to make the module as small as
possible.
program
your own chip or modify the program, the .hex file is available as well
as the assembly file, so you can see how the program has been written
and view the comments for each line of code.
The PIC12F629 is one of the smallest micros in the range but you will be
surprised how much can be achieved with such a tiny micro.
The program contains sub-routines to produce delays, sequences on the
display and both read and write EEPROM; jobs that require accurate code
- including a special sequence - called a handshaking sequence that
prevents the EEPROM being written due to glitches.
Even a program as simple as this is not easy to put together and to
assist in this area, we have provided a whole raft of support material.
Not only do we provide a number of programs with full documentation but
our approach to programming is simple.
It involves a method of "copy and paste" whereby sub-routines
are taken from previously written code and copied into your program. Any modifications are
made in very small steps so that each can be tested before adding more
code.
This is exactly how we produce a complex project. Each step is written
and tested before adding the next step.
This saves a lot of frustration as it is very easy to add a line
of code that is incorrect and get an unsuspected result.
If you follow our suggestions you will buy a programmer ("burner")
called a PICkit-2 if you are using a laptop. It is the cheapest and best on the market
and comes with
a USB
cable and 2 CD's containing the programs needed to "burn" the chip.
If you are using a desk-top and/or tower with a serial port, you can use
a cheaper programmer called MultiChip Programmer from Talking
Electronics. You
will also need NotePad2 to write your .asm program. This can be
downloaded from Talking Electronics website. You will use
LED_FX.asm or
LED_FX-asm.txt as a template for your
program, plus a 6 pin to 5 pin connector that fits between the burner
and the project. This is also available on Talking Electronics website.
As we said before, this project is for medium-to-advanced programmers as
it is very compact and does not have in-circuit programming pins.
To be able to modify the chip you will need a programming socket and
this can be obtained from one of our other projects that contains the 5
pins for in-circuit programming.
You can then put the chip into the other project to be programmed and
modified and re-fit it into this project for execution.
PROGRAMMING LANGUAGE
There are a number of kits, programs and
courses on the market that claim and suggest they teach PIC Programming.
Most of these modules and courses use a PIC microcontroller as the chip carrying out
the processes, but the actual programming is done by a proprietary
language invented by the designer of the course.
Although these courses are wonderful to get you into "Programming
Microcontrollers" they do not use any of the terms or codes that apply
to the PIC microcontroller family.
All our projects use the 33 instructions that come with the PIC
Microcontroller and these are very easy to learn.
We use the full capability of the micro and our pre-programmed chip is
less than the cost of doing it any other way.
In addition, anything designed via our method can be instantly
transferred to a PIC die and mass produced. And we use all the input
pins and all the memory of the chip. The other approaches
use less than 25% of the capability of the memory and one of the pins is not available.
In fact it would be difficult to reproduce this project via any of the opposition
methods. It would require a larger chip and more expense.
You can use our method or the opposition. Just be aware that the two are
not interchangeable.
Ours is classified as the lowest "form" (level) of programming - commonly called
machine code - invented in the early days of microprocessors - and now
called mnemonic programming as each line of code is made up of
letters of a set of words. The opposition uses a higher level language
where one instruction can carry out an operation similar to a
sub-routine.
But you have to learn the "higher level language" in order to create a
program. And this requires a fair amount of skill and capability.
It sounds great and it is a good idea. But if you want to learn PIC
programming, it does not assist you. It is "a step removed" from
learning PIC language. The other disadvantage of the opposition is the
"overhead." The 1,000 spaces allocated for your program is filled with
pre-written sub-routines. You may require only 10 of these sub-routines but ALL
of them are loaded in the memory space. And they take up all the memory.
You have no room for your own program.
To get around this the opposition uses a 93LC56 EEPROM to deliver
instructions on how to apply the sub-routines. This provides about 80 powerful instructions using their
language called BASIC (or a similar language).
It's a bit like selling a diary filled with all the paragraphs you need
to express yourself, and leaving a few blank pages at the back for you
to write single lines such as: see page 24, paragraph 7, see page 63
paragraph 4, to create your diary entries.
A detailed report on the BASIC Stamp-1 is HERE.
It depends on how much you want to be in charge of writing a program. Using
our method is like writing your own auto-biography. Using the opposition
is like getting a "ghost writer."
When using a higher level language to create a program, you have absolutely no
idea how the code is generated for the micro.
In some of the developmental kits, the code is "locked away" and you are
NEVER able to access it.
Everything runs smoothly until a fault occurs. With our method you can
see the code. With the other methods, you cannot see the code - it's
like doing key-hole surgery without the advantage of an
illuminated endoscope to see what you are doing.
Everything has its place and our method of hand-assembly is only
suitable for very small micros and you will eventually need to "learn a
high level language." The PIC12F629 has over 1,000 locations for code
and this equates to more than 20 pages when printed, so this is about
the limit to doing things by hand.
But our drive is to show how much can be done with the simplest devices
on the market, at the lowest cost.
Anyone can show you high-technology at a high price but this is not
where you start and this is not where you get enthusiasm.
We provide the things to get you started. That's the difference.
OTHER PROJECTS
Many of the ideas
you want to do have already been done in our PIC Projects section, such
as driving a servo, producing a RUNNING SIGN, a LED chaser, an Audio
CRO, a Touch Switch, Displaying letters on an 8x8 matrix. PIC Fx project
has been developed for NEW ideas.
Almost any program you want to write will be able to utilize
sub-routines that have already been written.
That's why it is best to look at all the projects in the PIC Projects
section to familiarize yourself with what has been done.
You can then create a new program by copying and pasting routines onto
the new template.
No matter what you are doing, you have to build a program "one small
step at a time." This is to avoid frustration.
The biggest problem with any program is interfacing a switch.
Notes on this are on the website under WRITING A PROGRAM.
The other helpful tip is to produce a marker so you know what the micro
is doing.
The marker may be to let you know the contents of a file, or if the
micro has executed a certain sub-routine.
To do this you add a small routine to flash a LED or output a tone to a
piezo. You must be in control with each new sub-routine you add. It must
work before you go on to the nest next addition.
If you think you can write a program, AND IT WILL WORK FIRST TIME, you
are better than me and you don't need any advice.
No other site ASSISTS you in writing a program.
They all give the impression that everything will work as soon as you
turn on the power.
The only way you can guarantee success is to do things in small steps.
MODIFYING THE
PROGRAM
To write programs or modify the project is a whole new world of learning
and is covered in the next pages of this project.
To write a program you will need a PICkit-2 programmer.
The
PIC Fx PROGRAM
The PIC Fx program does a bit of
detecting when turned on. It detects to see if a bit has been set in
EEPROM to tell the micro to go to a required sequence or start with
sequence 1.
It also detects if switch A, B or C has been pressed at the instant the
project is turned on so that the micro is directed to the sub-routine
where the user-sequence can be entered or if the EEPROM bit is to be
cancelled or if programs Code Lock, Reaction Timer or 4-Alarm sounds are
being accessed.
All this gets done in the SetUp routine and then the micro goes to one
of the routines in the MAIN section of the program.
Increments a "jump" file and calls a table where it
finds a directive to go to a particular sub-routine.
The sub-routine is executed and the micro goes back to Main where it
looks for a release of SwA. This forms part of a key debounce as the key
must be fully debounced as it is advancing the micro through the
sequences.
To provide a totally reliable debounce, the key is detected as not being
pushed for the duration of a whole cycle of a sequence and a separate loop is then executed where the key can be
detected as being pushed, to advance the program to the next sequence.
To create your own sequence as sequence1, the project is turned off and
SwA pressed while turning the project ON.
This sends the micro to a sub-routine called Attract.
As soon as SwA is released, the program starts to time the duration when
a switch is not pressed and it "times-out" after 2.5 seconds.
The program also times the duration when a LED is illuminated. It also
accepts 2 or 3 LEDs illuminated at the same time. These are all clever
instructions that need to be looked at to see how they operate.
Up to 15 steps can be entered and each step occupies three bytes. The
first value identifies the illuminated LEDs, the second byte identifies
the ON duration (in increments of 5mS) and the third byte identifies the
OFF time.
These 45 bytes are contained in files 30h to 5Fh.
When a switch is not pressed for 2.5 seconds, the program "times out"
and sends the values to the EEPROM. It then shows the sequence on the
LEDs.
If the project is turned off and on again, this sequence will be
displayed as sequence1.
To replace the sequence with something else, simply repeat the steps above.
If you want one of the pre-programmed sequences to appear each time the
project is turned on, simply advance through the sequences by
pressing SwA and when the desired sequence is playing, push SwB.
This will record your choice. Turn the project OFF then ON again and the
chosen sequence will be displayed.
To remove this feature, press SwC when the project is off and at the
same time, turn the
project ON.
All these feature have been added to the program, one at a time, and it
is important to add them in the correct order. For instance, you can only add a removal feature after the
initial feature has been produced. Reading and writing to the EEPROM is
a most complex operation and the instructions must be laid out as shown
in the program, as they include a hand-shaking sequence. When you need this
code it is copied and
pasted in its entirety, to prevent a mistake.
Nearly every instruction has a comment to explain not only what it does, but why it was chosen.
If you think you can start programming without reading programs from
other developers, you are wasting your time.
No individual can work how to do many of the tasks via the simplest set
of instructions and you will find some programmers have used complex
code to do the simplest task.
That's why you have to pick out the "wheat from the chaff" and
remember a good routine, while discarding the over-complex sets of code.
This brings up an important point.
Don't expect to be an A1 programmer in a week. It takes time to absorb
the skills of programming and it is really only understood by a
microscopic percentage of electronics enthusiasts. If you take it up and
understand it, you are one of the microscopic few.
It is a world that, once you are in, will open up a whole new field of
ideas and development.
It's like taking up a new spoken language and, in fact, a program reads
like a book, so the analogy is very close.
There are some very "clever" instructions such as XOR where you can
compare two files by using the XOR function and determine if they are
the same. And very powerful instructions such as djnz that decrements a
file and if it is zero, the micro jumps over the next instruction.
Other clever instructions transfer the contents of a file to another via
the "carry."
You cannot be expected to know these "tricks" unless you
study programming. That's why we are here.
Here are the files you will need:
LED_FX.asm
LED_FX-asm.txt
LED_FX.hex
;*******************************
;;PIC Fx.asm
; 11-3-2010
;*******************************
list p=12F629
radix dec
include "p12f629.inc"
errorlevel -302 ; Don't complain about BANK 1 Registers during assembly
__CONFIG _MCLRE_OFF & _CP_OFF
& _WDT_OFF & _INTRC_OSC_NOCLKOUT ;Internal osc.
;_MCLRE_OFF - master clear must be off for gp3 to work as input pin
;****************************************************************
; variables - names and files
;****************************************************************
temp1 equ 20h ;
temp2 equ 21h ;
temp3 equ 22h ;
temp4 equ 23h ;
jump equ 24h ;jump value for table1
fadeUp equ 25h
fadeDwn equ 26h
sequences equ 27h
sw_duration equ 28h
testing equ 29h
;****************************************************************
;Equates
;****************************************************************
status equ 0x03
rp1 equ 0x06
rp0 equ 0x05
GPIO equ 0x05
status equ 03h
option_reg equ 81h
; bits on GPIO
pin7 equ 0 ;GP0 LED C
pin6 equ 1 ;GP1 LED B
pin5 equ 2 ;GP2 LED A
pin4 equ 3 ;GP3 Sw A
pin3 equ 4 ;GP4 Sw B
pin2 equ 5 ;GP5 Sw C
;bits
rp0 equ 5 ;bit 5 of the status register
;****************************************************************
;Beginning of program
;****************************************************************
org 0x00
nop
nop
nop
nop
nop
SetUp bsf status, rp0 ;Bank 1
movlw b'11111000' ;Set TRIS GP0,1,2 out GP3,4,5 input
movwf TRISIO ;
bcf status, rp0 ;bank 0
movlw 07h ;turn off Comparator ports
movwf CMCON ;must be placed in bank 0
clrf GPIO ;Clear GPIO of junk
call _memory
btfss gpio,5 ;SwA to: "record new sequence"
goto record
btfsc gpio,3 ;SwC removes attract sequence
goto $+.10
movlw 0FFh
bsf status,rp0 ;select bank1
movwf EEDATA
bcf status,rp0 ;select bank0
movlw .101
bsf status,rp0 ;select bank1
movwf EEADR
bcf status,rp0 ;select bank0
call write
movlw .101
bsf status,rp0
movwf EEADR
bsf EECON1,0 ;starts EEPROM read operation. Result in EEDATA
movf EEDATA,w ;move read data into w
bcf status,rp0
xorlw .8 ;look for 8 - for Attract mode
btfsc 03,2
goto Attract_Seq ;selected sequence will appear first
goto Main
;****************************************************************
;* Tables *
;****************************************************************
table1 addwf PCL,F ;02h,1 add W to program counter
retlw .10 ;
retlw .50
retlw .30 ;
retlw .50
retlw .100 ;
retlw .40 ;program starts at bottom of table
retlw .10 ;
retlw .50
retlw .30 ;
retlw .50
retlw .60 ;
retlw .10 ;
retlw .50
retlw .10 ;
retlw .50
retlw .100 ;
retlw .20 ;
retlw .50
retlw .30 ;
retlw .50
retlw .70
retlw .60 ;
retlw .100 ;
retlw .50
retlw .100 ;
retlw .50
retlw .100 ;
retlw .70 ;
retlw .50
retlw .30 ;
retlw .50
retlw .70 ;
table2 addwf PCL,F ;02h,1 add W to program counter
goto seq1
goto seq2
goto seq3
goto seq4
goto seq5
goto seq6
goto seq7
goto seq8
goto seq9
goto seq10
goto seq11
goto seq12
;****************************************************************
;* Delays *
;****************************************************************
_xuS movwf temp2
_uS movlw .10
movwf temp1
decfsz temp1,f
goto $-1
decfsz temp2,f
goto _uS
retlw 00
_ZuS movwf temp2
goto $+2
goto $+2
decfsz temp2,f
goto $-3
retlw 00
_xmS movwf temp2
_x nop
decfsz temp1,f
goto _x
decfsz temp2,f
goto _x
retlw 00
;5mS delay for increments in timing for "New Sequence"
_5mS movlw 05h
movwf temp2
_5 nop
decfsz temp1,f
goto _5
decfsz temp2,f
goto _5
retlw 00
_10mS movlw 0Ah
movwf temp2
_10 nop
decfsz temp1,f
goto _10
decfsz temp2,f
goto _10
retlw 00
_50mS movlw .50
movwf temp2
_50 nop
decfsz temp1,f
goto _50
decfsz temp2,f
goto _50
retlw 00
_100mS movlw .100
movwf temp2
_100 nop
decfsz temp1,f
goto _100
decfsz temp2,f
goto _100
retlw 00
_150mS movlw .150
movwf temp2
_150 nop
decfsz temp1,f
goto _150
decfsz temp2,f
goto _150
retlw 00
;****************************************************************
;* Sub Routines *
;****************************************************************
_memory
movlw .48
movwf temp1
movlw 2Fh
movwf fsr
incf fsr,f
movlw 0FFh
movwf indf
decfsz temp1,f
goto $-4
retlw 00
;SwB puts current sequence into EEPROM for turn on.
;and puts "marker" in location 101
Attract
movf sequences,w ;put sequence number into w
bsf status,rp0 ;select bank1
movwf EEDATA
bcf status,rp0 ;select bank0
movlw .100
bsf status,rp0 ;select bank1
movwf EEADR
bcf status,rp0 ;select bank0
call write
movlw .8
bsf status,rp0 ;select bank1
movwf EEDATA
incf EEADR,1
bcf status,rp0 ;select bank0
call write
nop
goto $-1 ;Project must now be turned off
;Seq selected as Attract will be displayed when project turned on
Attract_Seq
movlw .100
bsf status,rp0
movwf EEADR
bsf EECON1,0 ;starts EEPROM read operation. Result in EEDATA
movf EEDATA,w ;move read data into w
bcf status,rp0
movwf temp4
movf temp4,w
call table2
goto $-2
;record new sequence - looks for "no switch pressed" for 1.25 seconds to exit
;uses files 30h to 5Fh (48 files)
;three files per "step" 1st file = LEDs, 2nd = Off time, 3rd = on time
;15 steps allowed - look for 5Dh
record btfss gpio,5 ;wait for release of button A
goto $-1
movlw 30h
movwf fsr ;start storage at file 30h
;look at keys being pressed - identifies 2 or 3 keys pressed together
_r1 clrf sw_duration
_r1a call _5mS
incfsz sw_duration,1 ;5mS x 256 = 1.25seconds
goto $+2
goto Store ;time out! store files 30h to 5Fh in EEPROM
btfss gpio,5 ;see if one or more Sw is pressed
goto $+5
btfss gpio,4
goto $+3
btfsc gpio,3
goto _r1a ;no sw pressed create 2.5 sec timing
;1,2,or 3 sw pressed
call _10mS ;delay to detect 2 or 3 switches
incfsz sw_duration,1
goto $+2
goto Main
btfsc gpio,5 ;SwA
goto $+2
bsf gpio,0 ;turn on LED A
btfsc gpio,4 ;SwB
goto $+2
bsf gpio,1 ;turn on LED B
btfsc gpio,3 ;SwC
goto $+2 ;
bsf gpio,2 ;turn on LED C
;LEDs have been illuminated
movf gpio,w
movwf indf ;w moved to fsr's file (30h+)
incf fsr,f
movf sw_duration,w ;off time!!
movwf indf ;w moved to fsr's file (30h+)
incf fsr,f
clrf sw_duration
_r2 call _5mS
incfsz sw_duration,1
goto $+2
goto record ;time out! keys pressed too long. Start again
btfss gpio,5
goto _r2 ;sw pressed
btfss gpio,4
goto _r2 ;sw pressed
btfss gpio,3
goto _r2 ;sw pressed
;file empty. Put duration into file
movf sw_duration,w ;on time
movwf indf ;w moved to fsr's file (30h+)
incf fsr,f
movlw 5Dh
xorwf fsr,w
btfss 03,2
goto $+2
goto Store ;stop at 15 steps. store files 30h to 5Fh in EEPROM
clrf gpio
goto _r1
;sequences:
;seq1 Self-Programmed sequence
;1St file:LEDs 2nd file:OFF time 3rd file:On time
seq1 bsf status,rp0
clrf EEADR
bcf status,rp0
bsf status,rp0
bsf EECON1,0 ;starts EEPROM read operation. Result in EEDATA
movf EEDATA,w ;move read data into w
bcf status,rp0
movwf gpio
bsf status,rp0
incf EEADR,1
bsf EECON1,0 ;
movf EEDATA,w ;move read data into w
bcf status,rp0
movwf temp4 ;this is OFF time. Store it
bsf status,rp0
incf EEADR,1
bsf EECON1,0 ;
movf EEDATA,w ;move read data into w
bcf status,rp0
movwf sw_duration ;this is ON time
call _5mS
decfsz sw_duration,1
goto $-2
clrf gpio
call _5mS
decfsz temp4,f ;create OFF duration
goto $-2
bsf status,rp0
incf EEADR,1
bsf EECON1,0 ;
movf EEDATA,w ;move read data into w
bcf status,rp0
xorlw 0FFh ;look for 0FFh - end of routine
btfss 03,2
goto $-31
retlw 00
;seq2 chase right - very fast
seq2 bsf gpio,0
call _100mS
bcf gpio,0
bsf gpio,1
call _100mS
bcf gpio,1
bsf gpio,2
call _100mS
bcf gpio,2
call _100mS
clrf gpio
retlw 00
;seq3 chase right
seq3 bsf gpio,0
call _150mS
bcf gpio,0
bsf gpio,1
call _150mS
bcf gpio,1
bsf gpio,2
call _150mS
bcf gpio,2
call _150mS
clrf gpio
retlw 00
;seq4 chase right with off-delay at end
seq4 bsf gpio,0
call _150mS
bcf gpio,0
bsf gpio,1
call _150mS
bcf gpio,1
bsf gpio,2
call _150mS
bcf gpio,2
call _150mS
retlw 00
;seq5 left right left right
seq5 bsf gpio,0
call _150mS
bcf gpio,0
bsf gpio,2
call _150mS
bcf gpio,2
retlw 00
;seq6 middle on middle off
seq6 bsf gpio,1
call _150mS
bcf gpio,1
call _150mS
clrf gpio
retlw 00
;seq7 All on all off
seq7 clrf gpio
call _150mS
decf gpio,f
call _150mS
clrf gpio
retlw 00
seq8 ;seq8 middle on then sides on
bsf gpio,1
call _150mS
bcf gpio,1
bsf gpio,0
bsf gpio,2
call _150mS
clrf gpio
retlw 00
;seq9 police flasher 3 times left 3 times right
seq9 bsf gpio,0
call _50mS
bcf gpio,0
call _50mS
bsf gpio,0
call _50mS
bcf gpio,0
call _50mS
bsf gpio,0
call _50mS
bcf gpio,0
call _50mS
bsf gpio,2
call _50mS
bcf gpio,2
call _50mS
bsf gpio,2
call _50mS
bcf gpio,2
call _50mS
bsf gpio,2
call _50mS
bcf gpio,2
clrf gpio
call _50mS
retlw 00
;seq10 random flicker
seq10 movlw .32 ;start at bottom of table
movwf jump
bsf gpio,1
movf jump,w ;put table jump value into w
call table1
call _xmS
bcf gpio,1
decfsz jump,f
goto $+2
retlw 00 ;top of table found
movf jump,w ;put table jump value into w
call table1
call _xmS
goto $-11
;seq11 slow fade up down
seq11 clrf fadeUp ;
clrf fadeDwn
incf fadeUp,f ;to create 1 (delay routine does not like 00)
bsf gpio,1
movf fadeUp,w
call _xuS
bcf gpio,1
movf fadeDwn,w
call _xuS
decfsz fadeDwn,f ;
goto $-8
incf fadeDwn,f ;to produce 1
bsf gpio,1
movf fadeUp,w
call _xuS
bcf gpio,1
movf fadeDwn,w
call _xuS
decf fadeUp,f
incfsz fadeDwn,f
goto $-8
clrf gpio
retlw 00
;seq12 fast fade up down
seq12 clrf fadeUp
clrf fadeDwn
incf fadeUp,f ;to create 1 (delay routine does not like 00)
bsf gpio,1
movf fadeUp,w
call _ZuS
bcf gpio,1
movf fadeDwn,w
call _ZuS
decfsz fadeDwn,f ;
goto $-8
incf fadeDwn,f ;to produce 1
bsf gpio,1
movf fadeUp,w
call _ZuS
bcf gpio,1
movf fadeDwn,w
call _ZuS
decf fadeUp,f
incfsz fadeDwn,f
goto $-8
clrf gpio
retlw 00
;Store Store the 15 steps in EEPROM
Store bsf status,rp0 ;select bank1
clrf eeadr
bcf status,rp0 ;select bank0
movlw .48
movwf temp1
movlw 2Fh
movwf fsr
incf fsr,f ;fsr starts at file 30h
movf indf,w ;retreive data in file 30h
bsf status,rp0 ;select bank1
movwf eedata ;
bcf status,rp0 ;select bank0
call write
bsf status,rp0 ;select bank1
incf eeadr,1
bcf status,rp0 ;select bank0
decfsz temp1,f
goto $-10
goto Main
write bsf status,rp0 ;select bank1
bsf eecon1,wren ;enable write
movlw 55h ;unlock codes
movwf eecon2
movlw 0aah
movwf eecon2
bsf eecon1,wr ;write begins
bcf status,rp0 ;select bank0
writeA btfss pir1,eeif ;wait for write to complete
goto writeA
bcf pir1,eeif
bsf status,rp0 ;select bank1
bcf eecon1,wren ;disable other writes
bcf status,rp0 ;select bank0
retlw 00
;****************************************************************
;* Main *
;****************************************************************
Main clrf sequences
movf sequences,w
call table2
btfss gpio,5 ;Is swA still pressed?
goto $-3 ;SwA still pressed
movf sequences,w ;SwA released
call table2
btfss gpio,4 ;SwB puts current sequence at turn-on
goto Attract
btfsc gpio,5
goto $-5 ;SwA not pressed
incf sequences,f
movlw .12
xorwf sequences,w
btfss 03,2
goto $-12
goto Main
;****************************************************************
;*EEPROM *
;****************************************************************
org 2100h
END |
GOING
FURTHER
We have not produced all the
possible sequences and you can add more by simply creating
a new sub-routine.
You need to add it to the table and make sure you end with retlw 00
to send the micro back to Main.
We have provided all the hardware and software for you to do this. Now
it's now up to you.
|
3
- 82R (820) SM
resistors
2 - 22k (223) SM
resistors
2 - 47k (473) SM
resistors
1 - 100n SM capacitor
1 - 10u tantalum
1 - SPDT mini slide switch
1 - LM78L05 voltage
regulator
1 - PIC12F629 chip (with
routines)
1 - 8 pin IC socket
3 - super bright white 3mm LEDs
3 - mini tactile switches
5 - machine pins
5 - component header pins
(alternative)
5cm fine tinned copper wire for link
1 - piezo diaphragm
1 - 9v battery snap
20cm very fine solder
1 - PIC Fx-1 PC board
|
|
P2
-
The Instructions
P3
-
writing your own program
14/6/14 |