save Cheap PIC Projects as .pdf

This series of projects will get you into building circuits using a tiny 8 pin chip called a microcontroller.
The PIC micro PIC12F629 is very cheap and the projects include a programmer for a desk-top computer and one for a lap-top computer - so you can do everything yourself. All the projects are backed by a kit to save you the trouble of buying the components individually. A kit costs less than sourcing the components yourself as some of the items are hard to get in small quantities. 
This eBook of projects is actually a PIC Microcontroller course to teach you programming microcontrollers.
Any courses that use a language (BASIC, JAL etc) do not actually teach microcontroller programming. They don't teach how a microcontroller interprets instructions or how to write PIC instructions.
It's up to you, how you want to learn about microcontrollers. All I can say is this: No-one has produced projects similar to ours using a high-level language, so you will be on your own.
We use just the 33 instructions provided by MicroChip to program the micro and in one of the projects we used almost the entire memory of 1024 locations. This is equal to about 20 pages of program and it's amazing what can be achieved.
The main reason why we are promoting hand-coding is this: If the program doesn't work, you know the fault is in the instructions. If you use a high-level language, you are not in control of the instructions and you don't know if the fault lies in your work or the instructions that have been produced by the "language."
Our whole aim is to remove the frustration and that's why we have provided a wide range of projects and you will shown how to create your own project by taking sub-routines that have already been produced and adding extra instructions.
We also have a Library of Routines that cover almost every requirement as well as a list of hints and Ideas.
Library of terms  A-E
Library of terms  E-P
Library of terms  P-Z
Using all these features will guarantee you success and this course is the only one of its type.

Here are the projects, but first we have an Introduction to Microcontrollers and Hints and Ideas to help you start in this field of electronics:
 

CONTENTS Introduction to the PIC Microcontroller   Hints and Ideas for the  PIC Micro Links PROGRAMMERS: PIC Programmer MkV for your desk-top computer Kit $xxx Plus $6.50 postage or $7.50 airmail PIC-2 USB Burner for your lap-top computer Kit $xxx Plus $6.50 postage or $7.50 airmail PROJECTS:

 

 

Introduction to the PIC Microcontroller  - P1 The PIC microcontroller we use in these projects has 8 pins and is one of the smallest and simplest micros on the market. There are lots of different manufactures of micros and nearly all have the same or similar features. We have picked the PIC micro because it has one of the largest resources on the web with the largest number of projects. This means you will get very good support and be shown how to get into microcontroller-designs at the lowest cost with a wide range of projects. You only need to buy a kit to get started. If you want to change any of the features in a project, you will need a programmer and from there you can start to create you own programs. Once you start with micro's you will see their advantage. A project that previously required a number of discrete components and IC's can now be achieved with a micro and less surrounding parts. On top of this, the program in the micro can be protected from prying eyes - so no-one can copy your design. This allows you to market your ideas and turn your skills into a career. Everything has been kept simple with terminology you will understand with each project  introducing new ideas. You can achieve an enormous amount with an 8-pin micro. It can take the place of 5 or more individual IC's and create a project that was previously impossible. But to gain skills in circuit-design and programming you must read the notes and construct as many projects as possible. Everything we have presented is important. There are new ideas in every project and there are lots of notes in the "links" section. So, let's start: You can start by buying any of the projects as they come with all components and a programmed microcontroller. All you have to do is solder the components onto the printed circuit board. If you want to modify the program YOU NEED A PROGRAMMER. Talking Electronics has designed two different programmers. PIC Programmer MkV connects to the serial port of a desk-top computer. PIC-2 USB Burner connects to the USB port of a lap-top. You will need a 6pin to 5 pin connector to connect the programmer to a socket that hold the PIC chip during programming. You will also need a socket and PC board to hold the PIC chip during programming. Lastly, you will need a project from the list above. To change any of the features in a project (or design your own), the PIC12F629 micro must be programmed or re-programmed (if it already has a program. This can be done about  1,000 times and you may  need to work on a program 100 or more times during its  development.  This is a simple task and just needs a programmer and the associated software as found in the programmer articles. The type of programmer mainly depends on your desk-top or lap-top computer as the communication port (plug) is different and the transfer protocol is totally different. WRITING  A PROGRAM   Writing a program starts by selecting a simple project and building the kit to see what the project does. Then you need to get you computer ready for  SOFTWARE DESIGNING or SOFTWARE PROGRAMMING. We use a method called HAND PROGRAMMING. where all the instructions are created by hand using the 33 instructions supplied by the manufacturers of the microcontroller. Each instruction is effectively a miniature sentence, made up of letters and numbers to tell you what the instruction is doing and which file it is associated with.  All the project come with the file you need and is is called the ASSEMBLY FILE or .asm To work on this file, it is loaded on a folder that will be used for all your PIC programming.  To do this, create a new folder and call it "_PIC Projects." on C-drive. This will place it at the top of the list of folders in C-drive.   Next copy  textPad and MPASM into this folder, along with PIC12F629inc. Right-click on textPad (and also MPASM) and send them to desk-top as a short-cut. Now, open textpad from the desk-top and load the .asm file associated with the project you are working on (such as xxssddd.asm for the the AudioCRO project.) You will see the program is laid out in columns. The first column contains Labels. This is a single word that must start with a letter or "_" (underscore) and a reference point to identify the start of a sub-routine or a location to send the micro, during the execution of a sub-routine, to repeat a number of instructions. The second column contains Directives (such as equ, end) and Mnemonics. A  Mnemonic is an instruction such as a word made up of letters to let you know what the instruction is doing. such as decfsz (decrement file "f" and skip if zero). The third column contains Operands. This is the file that will be operated on. (such as being  incremented, decremented or loaded with a value). The fourth column contains Comments (such as  ;make the output HIGH  ;test the zero bit. This describes why the instruction has been used and must be preceded with ";" so  the compiler does not read any of the instructions. Next, select an instruction with a value that determines a flash-rate. This can be done by going to the delay routine associated with the flash and increase the value of the register being loaded. This will increase the number of loops and thus increase the ON and/or OFF time. Or select an instruction with a value that appears on a display. In other words, select an instruction that you can observe when a change is made. Save the file as xxxx-1.asm Always save the file with a slightly different name so you know it has been saved. Sometimes, copying over the same file will not be carried out by your computer and you will wonder why the altered instructions do not work! It does not matter which programmer you will be using. Both require the same .hex file and this file will be produced by software called MPASM. This software is provided as freeware by microchip and is part of MPLAB. MPASM takes your .asm file and produces a .hex file (as well as other files that let you know if any mistakes have been made, such as the spelling of your instructions or anything to do with the running of the program. It does not correct any of your mistakes such turning on the wrong LED etc. Open MPASM from desktop and load the .asm file you have just created. Use these settings: Radix: default Warning Level: All Messages Hex Output: Default Generated File: Error File   List File Case Sensitive (untick) Tab Size: 8 Macro Expansion: Default Processor: 12F629 Save Setting on Exit (tick) Click Assemble. MPASM will produce a .hex file only if the program compiles correctly. If you have left out a Label or created a mistake, you should refer to the Error File and make the corrections listed in the file. Click Assemble again and the file will compile to produce a .hex file. Select the programmer suited to your computer and assemble it. If you have selected PIC Programmer MkV, connect it to the parallel port via the 8 pin D connector supplied with the kit. The red and greens LEDs will illuminate. If you have selected PIC-2 USB Burner, connect it to the USB port and the red LED will illuminate. Load either xxxxxx or   xxxeett  program into "_PIC Projects" folder and send xxxxxx to desk-top via the right-click of the mouse. You may also need the following programs to help in the installation of xxxxx.   eeee    dddd If ICPROG does not install, you can try WinPIC BURNING  A PROGRAM INTO A MICROCONTROLLER The next step is to "burn" the program into the microcontroller. This can also be called "programing the chip" or "Write" or "Write to the chip." The PIC Programmer MkV programmer already has a socket and the 8 pin chip to be programmed is fitted in the left-end of the socket. If you are using the PIC-2 USB Burner, connect the 6 pin to 5 pin adapter to the PIC-2 USB Burner project and connect the 5 pins to a PC board containing the 8 pin micro as shown in the following image: Click on  PICkit 2 Programmer on your desk-top and it will open. It will automatically read the name of the chip and display this in the window. Click on: File, then click on Import Hex. Locate the hex file in "_PIC Projects" folder. Click on Write and the chip will get programmed. Remove the chip from the socket and place in the project. Switch you project ON and the observe the changes you have made. If you have installed ICPROG, Click on ICPROG and

 

 

 

 

PIC Instructions Explained  - P3

Here are the 33 instructions explained in words: addlw number - adds a number (called a literal -  00 to FF) to the number in the working register. addwf FileReg, f - adds the number in the working register to the number in a file (FileReg) and puts the result in the file. addwf FileReg, w - adds the number in the working register to the number in a file (FileReg) and puts the result back into the working register, leaving the file register unchanged. andlw number - ANDs a number to the number in the working register, leaving the result in the working reg. andwf FileReg, f - ANDs the number in the working register to the number in a file (FileReg) and puts the result in the file register bcf FileReg, bit - clears a bit in a file (FileReg), i.e. makes the bit 0 bsf FileReg, bit - sets a bit in a file (FileReg), i.e. makes the bit 1 btfsc FileReg, bit - tests a bit in a file (FileReg) and skips the next instruction if the result is clear (i.e. if that bit is 0). btfss FileReg, bit - tests a bit in a file (FileReg) and skips the next instruction if the result is set (i.e. if that bit is 1). call label - makes the chip call any label, after which it will return to where it left off if the sub-routine contains retlw 00. clrf File - clears (makes 0) the number in a file (FileReg). clrw - clears the working register. clrwdt - clears the watchdog timer. comf FileReg, f - complements (inverts - ones become zeroes, zeroes become ones) the number in a file (FileReg), leaving the result in the file register. decf FileReg, f - decrements (subtracts one from) a file (FileReg) and puts the result in the file register. decfsz FileReg, f - decrements a file (FileReg) and if the result is zero it skips the next instruction. The result is put in the file. goto Label - makes the chip go to a label in the program. incf FileReg, f - increments (adds one to) a file (FileReg) and puts the result in the file. incfsz FileReg, f - increments a file(FileReg) and if the result is zero it skips the next instruction. The result is put in the file. iorlw number - inclusive ORs a number with the number in the working register. iorwf FileReg, f - inclusive ORs the number in the working register with the number in a file(FileReg) and puts the result in the file. movfw FileReg or movf FileReg, w - moves (copies) the number in a file(FileReg) in the working register movlw number - puts a number into the working register. movwf FileReg - moves (copies) the number in the working register into a file (FileReg). nop - this stands for : no operation, in other words - do nothing, (it is used to create a delay) option_reg - takes the number in the working register and moves it into the option register. retfie - (NOT FOR PIC16C5X SERIES) - returns from a subroutine and enables the Global Interrupt Enable bit. retlw number - returns from a subroutine with a number (literal) (from 00 to FF) in the working register. rlf FileReg, f - rotates the bits in a file (FileReg) to the left, putting the result in the file. rrf FileReg, f - rotates the bits in a file(FileReg) to the right, putting the result in the file. sleep - sends the PIC to sleep, a lower power consumption mode. sublw number - subtracts the number in the working register from a literal. To subtract 1 from W, use: addlw   255 subwf FileReg, f - subtracts the number in the working register from the number in a file (FileReg) and puts the result in the file. swapf FileReg, f - swaps the two halves of the 8 bit binary number in a file (FileReg), leaving the result in the file. movwf    tris PORTA  or     movwf    trisPORTB    or            movwf    trisio      for PIC12F629 - moves the value in w to the tris file. xorlw number - exclusive ORs a literal with the number in the working register. xorwf FileReg, f - exclusive ORs the number in the working register with the number in a file (FileReg) and puts the result in the file.

 

 

PIC Instructions Explained  - P4

Here is the set of 33 instructions explained in more detail: Mnemonic Code Example Action Flags Description addlw k ADDLW 2 W = W+2 C,DC,Z Add Literal and W addwf f,d ADDWF X,f X = X ADD W C,DC,Z Add W and f andlw k ANDLW 5 W = W & 5 Z AND Literal with W andwf f,d ANDWF X,f X = X & W Z AND W with f bcf f,b BCF X,0 X &= 0x01 - Bit Clear File bsf f,b BSF X,2 X |= 0x04 - Bit Set File btfss f,b BTFSS X,2 Skip next if X=1 - Bit Test file Skip If Set btfsc f,b BTFSC X,0 Skip next if X=0 - Bit Test file Skip If Clear call k CALL SUB Call SUB - Call Subroutine clrf f  CLRF X X = 0 Z=1  Clear f clrw -  CLRW W = 0 Z=1  Clear W clrwdt - CLRWDT - - CLeaR WatchDog Timer comf f,d COMF X,W W = ~X Z Complement f decf f,d DECF X,f X = X-1 Z Decrement f decfsz f,d DEFCZ X,W W = X-1, test Z - Decrement f, Skip if 0 goto k GOTO LABEL Jump to LABEL - Go to Address incf f,d INCF X,W W = X+1 Z Increment f incfsz f,d INCFSZ X,f X = X+1, test Z - Increment f, Skip if 0 iorlw k IORLW 33h W = W | 33h Z Inclusive OR Literal with W iorwf f,d IORWF X,W W = W | X Z Inclusive OR W with f movf f,d  MOVF X,W W = X Z  Move f (to W or f) movf f,d  MOVF X,F X = X Z (Use to set Z flag) movlw k  MOVLW 33h W = 33h -  Move literal into W movwf f  MOVWF X X = W Z  Move W to f nop - NOP - - No operation retfie - RETFIE - GIE Set Return from interrupt (and enable) interrupts retlw k RETURN xxh Returns xxh - Return with Literal in W rlf f,d RLF X,f X = X << 1 C Rotate left through carry rrf f,d RRF X,W W = X >> 1 C Rotate right through carry sleep - SLEEP - - Enter Sleep mode sublw k SUBLW 2 W = 2-W C,DC,Z Subtract W from Literal subwf f,d SUBWF X,f X = X-W C,DC,Z Subtract W from f swap f,d SWAP temp,f - - Swap nibbles in f xorlw k XORLW 45h W = W ^ 45h Z Exclusive OR Literal with W xorwf f,d XORWF X,W W = W ^ X Z Exclusive OR W with f

 But we don't want to scare you away so we have pre-programmed it so it's just like using any 8-pin chip.
The fact that it can take the place of 5, 10 or even more individual chips, turn a complex circuit into a very simple design, do things you never thought possible, is not a reason to shy away.
To make the introduction into microcontrollers SIMPLE AND EASY, we have given just a single page to each project and all the rest of the 10 pages of the article can be found on our website.
Starting is simple. All you have to do is put it together.
Once you see how much can be done with 8 pins, you can go to the Silicon Chip website to see the full details of the program inside the chip and all the other details of the project.
We have provided the full listing of the program with comments on each instruction. In addition we have provided a programmer for the chip and the software needed to carry out the "burning" (programming) process.

We have deliberately kept everything cheap and simple to get the beginner interested in this amazing area of electronics and by reading our on-line articles you will be shown how to start producing your own very simple programs to flash a LED or produce tones and beeps.
Our concept is a "cut and paste" approach where you use a pre-made template and add instructions from other projects or from a library.
We show how to do things in small steps and test the outcome before adding more instructions.
In this way a complex project can be developed with the minimum of frustration.
This is exactly the way we do things.
The project looks impressive in the end but it simply consists of "sub-routines" that perform a particular operation, effect or task.
We do not use any "languages" (called high level languages). We only use the 35 instructions that come with the PIC chip and these are presented in a single-page list.
There are many ways to write a program and become a programmer and we have taken the "beginners path."
With our method you will be programming in one night and in two nights you will hooked - just like hundreds of other readers. Many will will never go back to designing a 5-IC project.
Not only is a microcontroller project smaller, but it contains a chip with a program that can be protected from prying eyes; by a feature called CODE PROTECTION.
This makes it impossible to get the code out of the chip. If the chip is not code-protected, it can be "read" by the same same piece of equipment used to program the chip - we call the "burner."
By protecting your Intellectual Property, you have a product you can sell and thus develop a business.
There are so many products that need developing.
Products such as a missing pulse detector for children vulnerable to SIDS, timers for taking pills, gas detectors in the kitchen for town gas, and the list goes on.
Many projects that needed 5 or more IC's can now be transferred to a microcontroller-design.
I remember our first automatic dialler. It used cards that fitted into a socket. The circuit used 17 chips. It could now be done with one 8-pin microcontroller. But every phone now has a re-dial feature and many have 10 memories. So we have to think of something else. That's what you can do. Many of the things that need an answer can be done with a simple circuit and with a micro, you can solve even the more complex requirements.
 

GETTING STARTED
All the projects are backed-up with kits and a pre-programmed chip. Or you can build the circuit yourself on an experimental board and program the chip yourself . Or you can buy a kit and just put it together. The website shows you the different options. It doesn't matter if you want to do everything yourself or just put something together. The important part is getting started.
We have included the documentation on the description of the circuit as well as each instruction in the program. Plus a project for the programmer, a library of routines and data on the microcontroller. 
These projects are designed to be a learning experience.
Newcomers may think a microcontroller project is "too complex," "too expensive," or "beyond capability."
But microcontrollers are the way of the future and we are here to change things.
In the following articles we are going to give you a number of projects that are cheaper than using discrete components and IC's. There are other advantages, too. The PC board is smaller and the operation of the circuit can be altered to suit different requirements by changing the instructions in the micro.
You just need some tools to start, such as a good quality soldering iron, side-cutters and a multimeter.
 

Here are the projects:

 

But in the beginning the kits for these projects contain a pre-programmed microcontroller and everything can be soldered just like a conventional electronics kit.
 

Not all projects are suited to converting to a microcontroller design but many projects that use 4 or more IC's 


Here is an example of a project suitable for converting to a micro:

WRITING A PROGRAM (FOR BEGINNERS)
Wack-A-Mole circuit looks simple because the micro does all the work.
And the micro does all the work due to a program it contains.
And this program can be written by YOU if you follow our simple steps.
Writing a microcontroller program is one of the most interesting challenges.
It can be written in many different ways.
Just like a book or novel, the sentence-structure can be impressive or simple.
You can add instructions in a way that is easy to understand or add them in a way that requires a considerable amount of reasoning to see how they perform.
This is because some instructions are easy to understand and others are complex and the layout can be "linear" or "jumping all over the place."
An example of a simple instruction is: incf  count,f
This increments the count file and places the result in the file.
An example of a complex instruction is:   xorwf   count,w
This exclusively OR's the contents of w with the count file and places the result in w.
This is called a Boolean instruction or LOGIC instruction and each corresponding bit is OR'ed and if only ONE of the bits is "1" the result is "1."
The answer may be different with each pass of the routine and this makes it complex or difficult to determine, when you are looking through the lines of code. You need to work out the result so you can determine where the micro will "jump to" in the program.
Sometimes a program can be shortened by one or two instructions by using an instruction that performs a number of operations and has a number of results.
However you need to know all these outcomes to be able to follow the code and this makes it complex.
Fortunately, we have used only simple-to-understand instructions so you can read the lines of code "like a book."
We call this LINEAR PROGRAMMING.
The program runs though a routine called MAIN and calls a number of sub-routines. A sub-routine is any routine that is called more than once and is presented separately so that it only needs to be written once.
We call this LINEAR PROGRAMMING.
We have only used the 35 instructions supplied with the chip and not used any special or "underground" instructions known only to advanced programmers and assemblers.
As with everything you are trying to learn, if there is one thing that is unexplained, you get lost.
The 35 instructions we are using is called MACHINE CODE or MACHINE LANGUAGE as they can be read directly by the micro. The line of code (called the instruction) is converted directly into a value that is loaded into the chip. Rather than writing 100100110010, or a similar hex value: AD068, we use a short sentence as explained above.
For example: decfsz  count,f  tells the micro to decrement the count file and leave the result in the file. If the result is zero, the next instruction is jumped-over.
You will hear a lot of discussion about the best type of programming language to use, such as "BASIC" or "C" in place of Machine Language.
The choice is yours. All I can say is this:
You have decided to learn how to program a PIC microcontroller. All languages other than PIC MACHINE CODE keep you one step away from understanding how the chip operates and you are not learning anything about the codes it reads.
This also includes the product called PIC-AXE. You are using a programming language that can be ported to almost any microcontroller and the code you are producing has nothing to do with a PIC micro. The fact that a IC micro is used in some case is meter co-incidence. Almost any micro could be used.  In addition, this concept utilizes the micro to only a fraction of its capabilities and costs 4 times more than using a PIC chip. 
Secondly, when a program does not work, you do not know if your coding is incorrect or the instructions produced by the higher-level language are at fault. You don't know what the high-level language has prepared and it's very difficult to trouble-shoot. 
And thirdly, you need to learn how to write in BASIC or "C," whereas the 35 instructions that come with the PIC are available as a table and only take a few days to learn.
The PIC chip we are using has space for 1024 lines of code and when you consider the first 3-level chess game fitted into 1,000 lines of code (for a Z-80), you can see how much can be achieved.
1,000 lines of code occupies more than 20 printed pages and this is about the limit to "hand coding." But up to this level, Machine Code is the quickest way to learn.
In our case, coding is done at the level called mnemonics. This makes it easier for the programmer to write each line of code and a program called an ASSEMBLER converts each line of code into a train of "0's" and "1's." 
To make it easy to read a program, it is laid out so that MAIN is at the end and each sub-routine is placed in alphabetical order. Tables are placed at the beginning, then delays.
We also advise to use only the minimum number of sub-routines so it is easy to follow the flow of the program. Rather than create lots of short sub-routines, only produce those that are more than say 10 lines. Short sub-routines can be added to MAIN as included instructions.
But the biggest assistance to learning to program is our method of "copy and paste."
We have provided a library of terms and a library of sub-routines as well as lots of programs and any parts of these can be copied and placed into your program. All this can be found on Talking Electronics website along with lessons on programming.
See "Start Here with PIC12F629" in the left index and you will find the details on programming chips, including a programmer, a connector that fits between programmer and project, prototyping boards and a number of projects with fully explained programs.
We have everything to get you into PIC programming and the easiest way to start is to look at the program in this project.
Contrary to popular belief, you don't "start at the beginning."   You start "at the end" by removing a few lines of code and see what happens. Then you change a few values and see what happens. Then you add a few lines and see what happens.
There are also a number of forums on the web that deal exclusively with PIC micros and these are active 24 hours a day as enthusiasts from around the world are are constantly on-line to help. Try this forum: http://www.electro-tech-online.com/



 
WHY LEARN PROGRAMMING?
After all this discussion, some readers will ask: "Why learn to program?"
The answer is simple.
Go to a toy store and see what is on the shelves.
They have talking robots, games with LCD screens, sounds and effects at the push of a button. Gone are the days of a flashing LED and an amplified telephone. The toys of today include speech, InfraRed detection, colour screens and everything to impress a child.
Most of the toys are microcontroller based and when you consider there are millions of toys and each one is produced in the millions; the market is enormous.
But maybe you don't want to get into the toy market.
There are lots of other fields: medical, automotive, mobile phone, security and more.
Not only is a microcontroller cheaper than individual components but it produces a product that is protected from copying by the fact that the program can be "locked from prying eyes."
Even though this project is very simple it provides the gateway to the future and once you have the capability of writing a program under your belt, you can advance fairly quickly to more complex things.
But it is the starting point that we are famous for. Talking Electronics starts enthusiasts in electronics.
We have always said that building a project is worth a 100 pages of reading material and tens of thousands of hobbyists have already built one or more Talking Electronics kits.
Now is the era of the micro and this project is the starting point. Need I say more.


WHY PICK A PIC MICRO?
There are a number of different manufacturers of microcontrollers on the market and the obvious question is to ask is: "Why pick a PIC microcontroller?"
The author had a requirement to chose a micro for a project to be placed inside a greeting card. Ten different designs were developed, including a breath analyser, a game, flashing lights and similar novel ideas.
The production-run was to be 100,000 units of each and to make the project viable, it was intended to design the circuit using the cheapest micro.
After considerable investigation, the only reply from manufacturers and wholesalers was from  Microchip. The simplest micros were being phased out by the other manufacturers and this left only the PIC range.
In fact PIC has a chip designed for the Chinese market and is only available in China. That's the power of the Chinese.
If you intend producing a large run of a project, a die can be made and the chip will be produced as a COB (Chip On Board), but the set-up costs makes this only viable for very large runs. In addition, you must be sure the program is "bug-free" as a chip in the form of a die cannot be altered.
However the advantage of going from a program written for a PIC chip to the same device in the form of a die means the program can be directly copied across and no further programming costs are involved.
  
 
   



PRINTED CIRCUIT BOARD
This project has been built on a PROTOTYPE PC board.
There are three reasons for this.
Talking Electronics has designed a number of projects and they are all built on the same prototype board.
This allows you to buy a number of identical boards and built any of the projects as they appear on the web or in a magazine.
The board has been designed especially for surface-mount components and allows circuits to be built and tested using these tiny devices.
As you will very quickly find out, designing a circuit for surface-mount is completely different to through-hole components and most of the time you need to produce a board before anything can be constructed.
However the cost of a producing a board is quite expensive.
Our method reduces the cost to less than 10%.
Once you start designing with surface-mount you will never go back to through-hole as the project is smaller, more-compact and appears to be simpler.
Whenever you put a lot of effort into a project, your eventual goal should be towards commercialisation and the only way to make anything economical is with surface-mount.
With this in mind we have developed a universal surface-mount prototyping board.
The parts are connected with short wires and by careful layout, you will be preparing for the eventual trackwork of the board.
Most of the prototyping boards on the market are quire useless. They don't allow a circuit to be be laid out as it will appear in a final design.
With our prototype board, you can build the circuit exactly as you want it to eventually appear and this reduces the change of a mistake.
The last thing you want is a fault.
A mistake in the layout or the program will be very difficult to locate as it is very difficult to fault-find your own work.
By doing everything in small steps, the change of a mistake creeping in is minimised.

 
 

   


   

 
MORE
You need to look at the enormous amount of material on Talking Electronics website to see what can be done with a microcontroller.
A 180MB mini CD is available, filled with programming material and this would have to be equal to a stack of books one metres high.
There are so many advantages to designing with a micro.
Apart from the professional result; it can be cheaper, quicker and simpler.
And one of the features is the "good-size" memory.
As your code gets longer, you can call sub-routines already produced and this makes your program more and more powerful as you get towards the end of memory.
Of course we are not talking about Gigabytes of memory and a main-frame computer-system.
We are talking about a project that can be really quite impressive and could only be "dreamed-about" some 20 years ago.
One example that comes to light is a telephone dialler produced some 20 years ago. It used cards that fitted into a slot and dialed a phone number.
The box contained 16 simple logic chips and the unit cost more than $150.00.
This was equivalent to a weeks wages.
We can now produce exactly the same product for less than $20.00 using a PIC chip.
However it is not needed as every phone has redial and 10 number storage.
That's why we have to be on the look-out for new ideas. And these are lots of them.
One idea introduces another and it's simply a matter of considering things you will need and including elderly and sick friends and family.
All sorts of monitoring devices are needed as well as mechanical aids and equipment.
Nearly all inventions have come about due to personal need and that's why new tings are being invented all the time.



4 Alarm Sounds.asm
4 Alarm Sounds.hex

Below is the program written by the original designer of the project. It is complex and contains an instruction: movlw wabl_dir_mask ;change direction  This instruction is now allowed. Possibly it should be: movfw wabl_dir_mask ;change direction. I don't know how he was able to compile the program. I could not assemble it. 
Read through the program then look at the next program for PIC12F629. It is shorter, easier to read, has better sounds, includes sleep mode (100microamps) and a 3 minute timer. You can always learn from other peoples work.
 Here are some of the things to consider.
1. The second program has has fewer instructions for each sub-routine. For instance:
     decf      dwell,1 ; test if dwell = 0
     btfsc     ZERO
has been replaced with: 
   decfsz   dwell,1 ; test if dwell = 0
   goto       $-2    ;go up the program two instructions
2. The piezo lines toggle via the following instructions:
    movlw       b'00100001'
    xorwf        GPIO,1         ;toggle bits 0 & 5
This makes GP0 and GP5 change state each time the sub-routine is executed. You do not need to know the previous state of either line. They change state each time the sub-routine is called.
3.  Instruction:  goto $+1   uses 2 cycles and saves writing:    nop    nop  and saves one  line of code.

4 ALARM SOUNDS for PIC12F509

;	alarmt.asm	

__CONFIG _MCLRE_OFF & _CP_OFF & _WDT_OFF & _INTRC_OSC_NOCLKOUT 

GPIO	equ	6	
STATUS	equ	3		
PC	equ	2			
#define	CARRY	STATUS,0				
#define	ZERO	STATUS,2				
#define	outa	GPIO,0	;Output to Piezo - toggles with GPIO,5	
#defi			
 	decfsz	temp,1		
 	goto	Dec2			
 	clrf	GPIO	; leave all output lines LOW
 	retlw	0				

	end

4 ALARM SOUNDS for PIC12F629

;	alarm_4Sounds.asm	for PIC12F629   29-1-2010
;
;This program has goto mode 2,3 changed to produce 
;SPACE GUN with A0 and A1 HIGH 
;quiescent current = 100microamps
;
;
;
	goto 	SetUp

	end