Controller Troubleshooting

General Megajolt Questions and Answers

Moderators: JeffC, rdoherty, stieg, brentp

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Barry_D
Posts: 0
Joined: Mon Mar 01, 2004 3:20 pm

Controller Troubleshooting

Post by Barry_D »

Hi All,

I still haven't found the cause of my board not communicating with my PC... :( I need a little help troubleshooting. It's not my com ports, they work fine. And the board is getting power. The two chips and the crystal have been oriented correctly from the start, voltage regulator is fine, the map sensor is not a concern right now, the serial port contacts are all soldered fine and not bridging any other circuit, what does that leave?

Transistors, Zener Diodes, resistors, capacitors, and what else??? Where could a communication breakdown occur on the board with the serial port?

What about the orientation of resistors? I noticed Brent's board pics and Aaron's board pics show different resistors oriented differently, hmmmmmmm...

Help!

Barry :(
1974 2002 BMW wide body w/many mods...
Complete engine rebuild, 318i injection,
MJLJ & MegaSquirt. Phase 2 is the turbo,
then she's an M3 killin machine!
(=oo=)
Rock on Brent!

Barry Durham
barry@BMWupgrades.com
501 227-4365

brentp
Site Admin
Posts: 6282
Joined: Wed Jan 24, 2007 6:36 am

Hi Barry, I'm still lookin

Post by brentp »

Hi Barry,

I'm still looking into an alternate way to communicate with the controller. I was thinking of using Hyperterminal to manually send commands to it and see if any data gets sent back.

Otherwise, try taking some pictures of your work, front and back, as Paratime suggested. I'll try to get the file/upload feature working on the site, but in the meantime just email them to me.

Thanks,
Brent
Brent Picasso
CEO and Founder, Autosport Labs
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brentp
Site Admin
Posts: 6282
Joined: Wed Jan 24, 2007 6:36 am

Hyperterminal debug instructions

Post by brentp »

Barry,

Try this:

Open up Hyperterminal. create a connection, and configure it to connect directly to the com port # you have on your computer. (Make sure no other programs are using that com port- close all communication programs, including palm pilot sync programs)

When it asks for the communication settings, use the following:

Bits Per Second: 4800
Data Bits: 8
Parity: None
Stop Bits: 1
Flow Control: <b>none</b>

When you get to the main screen, send a capital 'C' to the controller. you won't see what you type echoed on the screen, but the controller should 'reply' with what looks like a bunch of garbage. This is equivalent to the config software requesting the current configuration.

Pressing 'S' returns the current runtime status; in my case it replys with a single 'Z' character.

If that doesn't work, try a different serial cable. Also, make sure you can prove the serial port works correctly, like with any other devices you might already have. Trying this on a different computer might be helpful as well.

Good luck,
Brent

Brent Picasso
CEO and Founder, Autosport Labs
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Paratime
Posts: 0
Joined: Sat Apr 17, 2004 12:47 am

Follow Up

Post by Paratime »

Barry,

Did you ever get your box working?

Barry_D
Posts: 0
Joined: Mon Mar 01, 2004 3:20 pm

Controller Troubleshooting

Post by Barry_D »

Hey Paratime,

Short answer, no. I found someone who has much more experience at PCB's than I do to help me out. I should know more in a couple of days.

Once my error is found, I'll post it on here to help the next guy who has the same problem. Stay tuned...

On a brighter note - I've been working on what's going to become the decal for the case on the MJLJ. Brent has to sign off on the final design, and will be posting it on here soon.

The decal is already looking MUCH better than the MegaSquirt decal!

Barry
barry@BMWupgrades.com
1974 2002 BMW wide body w/many mods...
Complete engine rebuild, 318i injection,
MJLJ & MegaSquirt. Phase 2 is the turbo,
then she's an M3 killin machine!
(=oo=)
Rock on Brent!

Barry Durham
barry@BMWupgrades.com
501 227-4365

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