KA24e open NVSRAM schematic

[uglykid]

Being fairly new to electronic assembly, (but not totally new to electronic modification and repair) I attempted assembling one of these out of a breadboard.

Since my ECU is not a Nissan ECU, the chip is turned 180 degrees, so I couldn't just use the provided overlay and make a DIY board. And I could not find a dual sided board I, so I grabbed a single sided board, and put the pad side up, put the stand-off and 74hc00 on the bottom, then put the simtek on top. Since the standoff was solid, there would have been no way for me to solder it on pad-side down.

I started soldering on the stuff mounted on the bottom of the board. Then programmed and tested the simtek, and broke the traces that needed it, and soldered the simtek straight to the board instead of using a chip-socket, because it could not be placed with the solid stand off on the opposite side of the board.. Then soldered the wires and resister straight to the legs of the simtek.

I've done a little bit of soldering so my work is not the neatest, but I tested every connection and there's no opens and no shorts.

Checked all the connections 3 times, made sure I didn't solder the chip in backwards, etc, etc...

101_7059 C&S.JPG (150.59 KB) Viewed 321 times

Put it in to try it out, and the ECU is dead as a doornail.

The only thing I can think of is that my wimpy little 15w rat-shack soldering iron was too hot, and fried the chip soldering straight to the legs?

Anybody know of a way of testing one of these chips in place like this, before I toss it in the trash and start over?

[undesiredshoe]

How did you program the chip?

[uglykid]

How did you program the chip?

With a Willem 3 clone..

Programmed 5 of them. One failed on verification after the first write but passed when it was written again, so I know they are verified. (I used a different chip)

[Calum]

I'm going to go out on a limb and say you've got something not wired correctly. Why not have a pcb made so you know what you've got matches your schematic design?

[uglykid]

I'm going to go out on a limb and say you've got something not wired correctly. Why not have a pcb made so you know what you've got matches your schematic design?

Thanks for the vote of confidence in my abilities...

The first one this is going to guy to write software and an interface to access it. (as I said, this is not for a nissan, so consult s/w will not work) Another of the prototypes will be going to a very expectant alpha tester who is looking to install this EFI setup on his racing boat and use it this summer..

Once the programming is underway, then I can learn layout software, design a board, and send it out to have some made. But I'll be making them SMT, to heck with all this dip soldering!!

[Calum]

Check out board houses that do 'bare bones' boards (boards without solder mask). The prices are usually pretty reasonable (under $100 for 5 boards). For bare bones boards I use Adavanced Circuits-

https://www.barebonespcb.com/!BB1.asp

...and for prototypes with solder mask I use PCBFabExpress (under $100 for 3)-

http://pcbfabexpress.com/index.jsp

You can find cheaper if you're willing to wait but I'm usually impatient for prototypes.

Board software isn't hard, there's just a learning curve to every different software and some 'gotchas' you learn when you have boards made (mostly involving putting things too close together or too close too close to the wall of an enclosure or getting the pinouts screwed up!). I use OrCad Capture for the schematic entry and OrCad Layout (no longer sold) for the actual layout. Super expensive software ($5k) and older than dirt, but that's why I keep a machine dedicated to running just it. It's not like a newer version is going to do anything different for this kind of stuff. It's like a lot of things, once you learn one software package there's really not much point in switching, even long after the company has moved on and is trying to sell you something else. I would probably try the gEDA stuff (linux) if I was going to learn something new from scratch, but there's freebie windows software too. Advanced Circuits has their own software (http://www.pcbartist.com/) but it pretty much ties you to ordering boards from them.

[bakgwailo]

Yeah, I used http://futurlec.com/PCBService.shtml for a run of normal 16bit DBs, didn't take too long and they were really cheap (think like 5 or 6 bucks a pop at 25 boards - that was with masks +image)...... quality was actually pretty decent, i thought they would be terrible. So far, all worked.

Also, if you write software for it, remember, VB and MS stuff is evil , Java or C/C++ w/ QT/GTK is the way (hurray for cross platformability!)

[uglykid]

Well, this is interesting... (at least to me)

I took another chip, and 2 chip-sockets, just wired in them to make the leg change for A14, and held the WE high so that it would enable the chip reads, and dropped it in the ECU. No SRAM writes, but it'll tell me if the reads work.

Same thing, no response. Ruh-roh raggy... Is there some incompatibility with my ECU and the SRAM?

Grabbed a VOM, and the ECU is not powering the chip at all. ECU Issue..

So either the whole thing is an ECU issue (which this ECU worked last time I used it a couple months ago) or I fried the ECU (which I don't know how I could have with no shorts)..

At least I have another ECU, more fun tomorrow after work!

[uglykid]

Yeah, I used http://futurlec.com/PCBService.shtml for a run of normal 16bit DBs, didn't take too long and they were really cheap (think like 5 or 6 bucks a pop at 25 boards - that was with masks +image)...... quality was actually pretty decent, i thought they would be terrible. So far, all worked.

Also, if you write software for it, remember, VB and MS stuff is evil , Java or C/C++ w/ QT/GTK is the way (hurray for cross platformability!)

Sounds cheap for boards... I'll look into that when I get that far.

We decided on C++ as soon as he decided to do the job.. We've worked together on other stuff like this before, and experienced the comm issues dealing with the newer languages.

Sheeeeeeeeeeeeit, I just realized I need to whip up a serial converter for him to use for this too... At least I thought of it now, not after I shipped him the rest of the hardware.

[jsd21hb]

can i use the ds1230ab? i looked up both datasheets and they look only slightly ffernt. i ordered a sample of the ds1230ab. here are both datasheets.
http://datasheets.maxim-ic.com/en/ds/DS ... S1230Y.pdf
notes-application.abcelectronique.com/148/148-47902.pdf
thanks.