I am currently working on a project that I am going to implement in my vehichle. I am using a compact flash style 1.4"x1.6"x .130" module. This module will have capability to store multiple .bins that will be selectable by simple switches. In addition I will make a adapter to accomadate programming this module in a standard programmer. And yes it will be flash so you can reprogram easily. I will have a socket to adapt the module to to a dip pinout to make it easy to interface w/ecu. This cf module will ease handling and reduce the risk of program corruption or prom damage do to ESD.


My final question is would any of you be interested in something like this? If so let me know so that I can keep quantities in mind when purchasing my parts.

 

I think Craig Moats has already beaten you to this idea. Dont let me put you off building one of your own though.

Simon

 

I am aware of craig's design. My target idea is mainly the use of the compact flash case for a good interface, and ease of handling.

 

If you make a interface so that you don't have to pull out the ECM to change chips that would be sweet

 

Depending on where the ECU is located you could have a remote location for the chip, however the ribbon cable should be as short as possible. My ECU is located under my jockey box, so I will try putting my CF receptacle in the jockey box.

 

CompactFlash would be a great idea!

Beyond the convenience, if you did it right on the software end, it would render an EPROM programmer unnecessary!

How much are those little SSFDC-to-Floppy adapters? Cheaper than a chip burner. Yeah, that'd be cool in itself, forget about the switching.

Those are my 2 cents. Make it so you give the user a distinct advantage, one of not needing a chip programmer would be great. Of course you could build in the switching as well.

Only other thing to think about is remote mounting so people can get to it...

 

The little compact flash reader/writers are very cheap, like 10 to 20 bucks:

http://cgi.ebay.com/ws/eBayISAPI.dll...tem=1380211201
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=1380199392
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=1380285249


I love the idea but how would you interface it to your ECM?

 

I'm sorry for the previous post of mine I have no knowledge of 'compact flash' devices and missunderstood your idea. Having looked at some of those E-bay pages I can see now what you mean. Those flash cards are used for example on digital camaras etc for storing pictures and data?
Its a great idea what you are planning to do I hope you get something working. It could be a big step forward for us all.

Simon

 

Well to start with, I am making my own version of a compact flash. This will include an array of flash chips (256, 512, etc...) I wan't to do an array so that if one device fails you have backup devices, otherwise if you have several programs on one device and it fails then you are stuck. I will probably start with two versions-

V1- Single Chip in CF case.
V2- Chip Array with chip select IC for Multiple Bins, in Cf case.

Unfortunately you will still have to program via PP etc... In the future I would like to implement normal Compact Flash and eliminate the PP.

Let me know what chip configurations that will suit most of the needs of Prom DIY's.

If anyone has input on bus speed/noise issues for a remote located chip, I would greatly appreciate your knowledge and ideas.

 

Sounds a fine idea.

Personally I would have a concern over driveability/longevity, however.

The GM parts have to operate in an enviornment of say +200/-40 degF (my ECM is in the engine bay); and the chips must make positive contact in an atmosphere of humidity/dirt/corrosion, over a long period of time.

My concern would be that a c/f card is perhaps not built to the same automotive spec. If your digital camera fails in traffic it's no big thing - but the engine losing contact on the freeway could be hazardous to my health.

In the words of some famous lawyer or other, "Build it and they will sue".

JMHO

 

Great thing about DIY... Who they gonna sue?

If at all possible, I would angle the project toward a standardized CF/SSFDC. You would be opening a whole new world of DIY to a large group of people for very low cost. That would be a significant contribution. I like the idea.

The other thing you're talking about is pretty sweet too. What I had thought about recently would be something like a pair of SRAMS that swapped off as MUXed buffers for an on-board EEPROM. Really, with battery backup if you had CMOS SRAMs you wouldn't even need the EEPROM. If you could wire up a serial interface for program updates...that's an emulator...

In terms of distances, I've started playing around. Trying some buffers/xmitters to deal with line capacitance issues and EEPROM exertion power capacity. Should have some pointers soon, but so far no big luck. This weekend should have some dick-around time...

 

To people whom may be worried about abuse of c/f, I am basically putting a tiny version of the device you are most likely using right now(flash instead of eprom or eeprom) into a compact flash case, in fact because the mass & weight of the device is smaller it will be less likely to have a failure. I would say the chances of an un-soldered dip package coming loose during operation is much higher. Compact flash is also used in industrial embedded applications.

As for the interface cable length, I think to start I will use no longer than a 1' shielded ribbon cable. After talking to old timer engineers the general rule of thumb tends to be ribbon cable less than 1 foot. I hear that noiseis a bigger issue in auto's rather than line capacitance(speed).

As for using standard compact flash: I am not sure about speed of the normal compact flash interface. I have found a supplier who offers disk on chip flash that is in a very small package, however they only have proprietary mass programmers at this point in time.

 

[QUOTE]Originally posted by Craig Moates
Great thing about DIY... Who they gonna sue?[QUOTE]

Well, (don't mean to go too far off topic here, but you asked) 'they' can sue anybody who supplied parts.

Take a look at the first paragraph here: http://www.law.cornell.edu/topics/pr...liability.html

A search on http://www.nytimes.com/ shows 336 articles on 'product liability' in the past 30 days. The WSJ is even more gloomy.

Something for the hobbyist to be aware of. I'll go back to "lurk mode" now. HTH

DrJ

 

Thank you for the links. It looks to me that you are safe as long as you test your design, leave the installation up to the person using the product, and cover your *** with appropriate warnings when marketing. Although may I remind you that when it comes to law, it is illegal to copy a eprom with manufacturers copyrighted programs on them.

This product will be use at your own risk!

The same goes for F@!$&*G with you car or truck ECU.

 

im gonna add my 2 cents whatever there worth these days. why not use a flash memory pcmcia card..??? alot of computers already have them. there easy to change. stone reliable in fact that what the chrysler db2 scan tool uses. and when i say tough i mean tough. i seen cards and shook my head and they work like a jiffy all beat up ad falling apart. wouldnt this be the best route. ??? and even though you wouldnt be able to emulate you could in theory desing a software app and a connecotr to emualte.

just my 2 cents.

 

I first looked at using the pcmcia card, however the only difference between the compact flash and pcmcia is that compact flash is 1/4 the size, unless you want more than flash it is a waste of space. The other thing about using retail flash products is speed, because they are at smallest 8mb and use a different interface to banks of memory internal to the device. This slows it down. but I plan to look into off the shelf flash products that can be programmed without the use of a eprom programmer.

And if more people would like the pcmcia case than I can easily
do that too. But keep in mint that I am using standard flash memory products as Craig has done, only I am implementing it into a handy interface.

 

i was not critizing the idea of using camera style compact flash. in fact i think its a great idea. i only brought up the idea of pcmcia flash cards because most of our computers have them already installed. being were a laptop crowd. i will greatly aprciate any thing you design. thanx alot for the good ideas.

 

I didn't think that you were critisizing my idea, and even if you did thats good, because that is the very reason I posted this topic is for feedback from the people whom might use this type of device. I feel the best ideas come from a lot of input from a lot of different people, otherwise you end up with something that is useful to you and a piece of junk to everyone else.

For now it won't matter if you have a compact flash reader or a pcmcia reader because this device will still need to be programmed with a pp or similar.

Thanks for the input.