Ready for assembly

Megajolt Kit assembly Question and Answers. Be sure to review the <a href="http://www.autosportlabs.net/MJLJ_V4_kit_assembly_guide">Kit assembly guide</a>

Moderators: JeffC, rdoherty, stieg, brentp

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vw16vt
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Joined: Mon Mar 01, 2004 3:20 pm

Ready for assembly

Post by vw16vt »

Hi Brent,
just about ready for assembly, is there a order to follow or just put everything on and solder one by one?

Math

brentp
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Joined: Wed Jan 24, 2007 6:36 am

I need to do a step by step-

Post by brentp »

I need to do a step by step- I was going to do it over the weekend, but ran out of time with other obligations.

Until I have the install instructions up, it basically goes like this:

* pull up schematic image.

1. build power supply circuit and install molex connector. install the 3 jumpers: R12 (zero ohm resistor), J1 and the unlabeled jumper that is to the left of the processor. Power up the unit and test for proper +5v and ground on power pins for processor, MAX232, oscillator and MAP sensor.

2. insert all of remaining resistors, capacitors, diodes and transistors. ** make sure you use the right zener diodes in the right places!
reference picture for transistor alignment- http://picasso.org/mjlj/images/mjlj_v2_open_case.jpg

3. install the IC sockets and the DB9

4. Check again for proper +5v on the processor, max232 and oscillator.

5. once that appears good, solder the oscillator, map sensor and plug in the processor and MAX 232.

6. power up and test voltages again- no smoke is a good sign. :)

Brent


Brent Picasso
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vw16vt
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Joined: Mon Mar 01, 2004 3:20 pm

ready for assembly

Post by vw16vt »

ok, that seems pretty easy. So far really lot easier than the MS unit. I was surprise to see pcb size, really amazing!

Was wondering on part pn2222a, to92 , what would be pin 1. Looking at the NTE book, but not sure if I read it correctly. Or even is that website correct for pin identification http://www.qsl.net/wb4vlq/pn2222rev0.pdf.

And, what would be zero ohm resistor, haven't find any at local electronic shops. Would 1ohm be correct, what do you think?

Do I need some real crimpers to be able to make the connector, what wires size should be acceptable? I can seem to find what connector pin correspond to what on the png schematic.

Math

brentp
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The zero ohm resistor is real

Post by brentp »

The zero ohm resistor is really a jumper- don't worry about it. :) There are two other jumpers- J1 and the 'undocumented' one to the left of the processor.

Here's a high res picture of the board (be nice on my bandwidth and save it to your local machine.. :) )
http://picasso.org/mjlj/images/hires/mj ... n_case.jpg

You can see the orientation of the transistors in this picture.

For the pin connectors, you can use 18-16 ga wire. just use some needle nose pliers and crimp the tabs down over the wire and solder. When you put the connector in the plug it should "click" into place.

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vw16vt
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Joined: Mon Mar 01, 2004 3:20 pm

connector wires

Post by vw16vt »

can you just tell me what would the connector pins are for, I mean like outputs, pip, saw, 12v, ground, shift lite, and is that all?

Luca Lagonigro
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Joined: Sun Feb 29, 2004 9:23 pm

Look at the top left corner o

Post by Luca Lagonigro »

Look at the top right corner of the schematics:

http://picasso.org/mjlj/source/schemati ... lj_sch.png

X2 is the output connector with its pin out.


brentp
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Correct - look at the schemat

Post by brentp »

Correct - look at the schematic, and for the ground and power, make sure you have the right one by examining the traces on the PC board. (for example, the ground goes to the middle terminal of the voltage regulator and also connects the (-) side of the power supply capacitors.)

Regards,
Brent


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vw16vt
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Joined: Mon Mar 01, 2004 3:20 pm

connector pin13 and pin4

Post by vw16vt »

Sorry, didn't even realize it was actually the connector. I was going to check the traces for power and ground, because need to test everything tonight. Just want to check two quick last things.

Pin 13, there's components hooked but no name, I would suppose that's the rev limit feature? Am I correct that, might not have been tested on car, would be to cut power to coil?

Pin 4 unused.

And one thing, the kx8 processor, is the latest v2.0.2 firmware already installed. Sorry but have no idea how the kx8 works, and how to check them out. Only used to the MS & related stuff. And one last question, what do you use to compile the firmware code.

Thanks.

Math

Update: Power circuit works perfect, guess was pretty easy assembly. If ever you want, could get some extra pictures, of connector with wires so that it's easier. And if you just don't have time, I could write a basic assembly guide. Since I did build it without knowing much, I can write something easier to understand for average people. I'm just offering.

Second Update: Tested with everything, communication works perfectly, modified the settings. Need to test with real car, can't wait, awesome.

TonyBray
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Joined: Wed Mar 03, 2004 12:49 am

Got my unit built last night except

Post by TonyBray »

I missed that 'undocumented' jumper. I will solder it in tonight and then power it up and see if it smokes. Then what? Without the rest of the stuff (36-1 wheel, VR, coil pack, etc.), can I connect to it and see if it is working from the tuning software?

--Tony
Almost ready to Jolt!

brentp
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Yes, you can hook it up to th

Post by brentp »

Yes, you can hook it up to the tuning software and verify that you can update/read the ignition configuration.

Yep, you should have the undocumented jumper installed- it's used for tying the ground circuit together to help prevent electrical noise (if you follow the trace around you'll see they're already electricall connected).

Brent
Brent Picasso
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dparsley
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Joined: Sun Feb 29, 2004 9:23 pm

Assembly

Post by dparsley »

I assembled mine just a bit differently. Taking a page from the Megasquirt, I installed both connectors first, then the sockets, followed by building the power supply and testing it, then installed the MAX232 and associated caps, then tested comms with it. Removed the chip, and finished off the assembly.

By doing it this way, a person will know exactly what component that's not working as soon as possible.

Bottom line is that it's really up to the builder how they want to proceed with assembly.

Do what ever works for you. I'm just paranoid that I may have a cold solder joint, and want to know about it asap.

Dennis

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