glitchbuster.com

Home  |  Latest Updates  |  Components/Products  |  Ordering

 

"El Cheapo" Programmer Parts and Info Kit - only $9.87

Would you like to build the El Cheapo programmer using the PC board included with Myke Predko's book PROGRAMMING AND CUSTOMIZING PICmicro® MICROCONTROLLERS?  I thought I'd assemble it to try it out, and to make sure that I included all the right parts in the kit.  Good thing I did, because there are a number of important corrections and updates since the book was written.  It was quite an "adventure," but the good news is that I include my hard-won experience with the kit, so you'll have an easier time.  

IMPORTANT - There is another version of the El Cheapo programmer described in Myke's newer book PROGRAMMING ROBOT CONTROLLERS, and also on his website as the "Homebuild Version."  The kit described on this page IS NOT for that version of El Cheapo.  I also have a parts kit for the "Homebuild" Version -- please email for details. 

This kit contains all the components you'll need to assemble El Cheapo, including:

Some things you will need, which ARE NOT included in the kit:

Or, go a little wild and build El Cheapo Grande...

Also included with the kit is information on making a few easy changes under the PC board so you can program 8, 14, 18, 28, and 40 pin PICs with only two ZIF sockets - 18 and 40 pin.  I call this "El Cheapo Grande" (photo at right).  You might want to assemble and test your El Cheapo first, to make sure it meets your needs, and then consider buying the ZIF sockets.  For initial testing you could install just the 18 pin IC socket, so there wouldn't be much de-soldering if you decide to install one or both of the ZIF sockets.  As you might expect, the 18 pin ZIF socket handles the 8, 14, and 18 pin PICs, and the 28 and 40 pin parts are programmed in the 40 pin ZIF.

Note that the ZIF sockets shown in the photo of El Cheapo Grande are not included in my El Cheapo parts kit, and also that some parts appear to be "missing" in the photo because they have been eliminated in Myke Predko's latest circuit revision.  The 14 pin DIP socket is still shown installed, but is no longer needed since the 8 and 14 pin PICs are now programmed in the 18 pin ZIF (after the simple modifications under the PC board).


IMPORTANT NOTES - PLEASE READ THOROUGHLY BEFORE ORDERING THE EL CHEAPO PARTS KIT

The parts included in the kit are for Myke Predko's version of the El Cheapo circuit that uses the circuit board included in the book.  Some of the parts are different values than shown in the book due to updates and error corrections.  Several of the original components have been eliminated from the latest circuit revision, and are therefore not included.  Three values are included for R2, since you may need to "adjust" it for best results with your PC's parallel port.  All the needed information is included with the kit and in Myke Predko's latest information -- I take you step-by-step through the process.

Also, at the time of this writing the latest El Cheapo software at www.myke.com/elcheapo.htm (version 0.84) does not support reading and making changes to the PIC's configuration fuse settings.  Depending on your application this can be a significant limitation.  As with some other PIC programmer software available on the Web, the newest PICs are not yet supported.  If you want to work with a 16F84A, the 16F628, or a 16F877, for example, you're in good shape.  But if you want to use one of the 8-pin Flash 12F675s, the exciting new 18-pin 16F88s, or one of the powerful 40MHz 18F452s, you'll need a different programmer (or at least different software).  Please understand that I am not trying to slam the El Cheapo -- I just want you to have the information that will help you decide which programmer is best for your needs.  

There is another important thing you should be aware of and fully accept before deciding to build the El Cheapo programmer - there is a chance that it may not work with your PC.  Despite Myke Predko's belief when he wrote the book, he has encountered some PCs that just don't have enough parallel port signal output for this version of El Cheapo to work reliably.  His circuit and software updates have helped, but there is a chance that El Cheapo will not work with your system.  I guarantee that all the components in the kit function properly, but can not guarantee that the El Cheapo you assemble will work with your system.  

I've heard of El Cheapo users who have experienced difficulty installing the El Cheapo software with newer versions of Windows, such as XP.  I suggest that you download the El Cheapo software from www.myke.com/elcheapo.htm and confirm that it runs on your system before ordering the parts kit.  

Please understand that I don't make enough on this kit to provide unlimited free troubleshooting consultation.  If you aren't comfortable with assembling and possibly troubleshooting the programmer, or the possibility that it may not work with your PC, then you might want to consider an assembled and tested programmer such as the excellent ME Labs Serial Programmer or ME Labs USB Programmer by microEngineering Labs.  They work with the latest PICs, come with great software, and I offer them at a discounted price. 

IMPORTANT UPDATE (FALL 2004) -  Most of this page was written over two years ago when I developed the El Cheapo parts kit and instructions.  Much has changed since then.  Myke Predko's El Cheapo software hasn't been updated for quite a while, and there are many new attractive PICs that are not supported by his software.  I've heard that there may be downloadable programming software from another source that supports the El Cheapo hardware and some of the newer PICs, but I don't know the details.  If you already have the El Cheapo circuit board included with the book it might be interesting to give it a try, but please think of it as an experiment rather than a near-certain route to a good PIC programmer.  

ORDERING THE EL CHEAPO PARTS KIT:  

The El Cheapo parts kit is $9.87, and it is eligible for my standard shipping price of $1.95 per order in the US.  You can also order any number of PICs and other electronic components at the same time with no additional shipping cost.  A few heavier items like the ACA-1 power adapter ("wall wart") do require additional shipping.  I'll be happy to give you an exact quote once I know your location (US postal ZIP Code).  Order part number ECK-2.1 for the kit with a 2.1 mm power connector (recommended), or ECK-2.5 if you prefer the 2.5 mm connector -- same price either way.  

Note: I suggest the 2.1 mm power connector, since it works with both 2.1 mm and 2.5 mm plugs.  The 2.5 mm connector cannot accept 2.1 mm plugs.  
Questions?  I will be happy to answer them -- please click here to send me an email.


* Power Supply Info
On the El Cheapo PC board next to the power jack it says "14+ Volts."  the El Cheapo Bill of Material in the book says "+ 14-volt AC/DC."  That just isn't enough.  You need a power supply that can deliver at least 16 VDC to the El Cheapo under operating load.  Let's take a look at the El Cheapo circuit diagram in the book for a moment, and you'll see why...

A 78L12 voltage regulator normally outputs 12.0 volts, but the diodes CR2 and CR3 bump up the voltage on the 78L12's ground reference pin to about 1.2 volts.  That "fools" the 78L12 into outputting approximately 13.2 volts.  This type of voltage regulator needs about two volts more at its input than it is required to output.  That means we should supply the 78L12 with at least 15.2 volts for correct operation.  Now take a look at diode CR4 between the power input connector and the 78L12 regulator.  On my El Cheapo there is a 0.8 volt drop across CR4.  Taking that into consideration, we must have at least 16 volts DC at the power input jack to get 15.2 volts at the input pin of the 78L12.  To confirm this, I powered my El Cheapo with 15.0 volts DC from a regulated bench supply, and -- no surprise -- it wasn't enough.  The output from the 78L12 was several tenths of a volt lower than normal.  If you need a power supply, my part number ACA-1 works great with El Cheapo. 


Home  |  Latest Updates  |  Components/Products  |  Ordering

Text and images copyright © by Randy Jones.  All rights reserved.