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Serial cable problem
Posted: Mon Apr 14, 2008 4:43 am
by pommie02
I think I need to take up drinking or smoking...or both.
can anyone tell me what the connections should be in the serial

port ?
i have a red in 2
white in 3 and an earth in 5.
what is there position at the jack plug
ie..is pin 2 at the end of the jack plug..
thanks gary
Re: Serial cable problem
Posted: Mon Apr 14, 2008 5:15 am
by pommie02
i have found the info i needed...but i still am unable to connect up to megasquirt.
i have checked my serial port (7)..and set the same in megatune ..but i cant get a connection
Re: Serial cable problem
Posted: Tue Apr 15, 2008 5:21 am
by Matt Cramer
Let's see if something else will communicate with it. To do this check, you'll need the program portcheck.exe, which comes with most MegaTune versions, including the one on the DIYAutotune.com website. You'll find it in the MegaTune2.25 folder. If you don't have a copy, let me know and I can send you one.
Power up the Microsquirt and connect it to your PC. You do not need to open the case and should not put the boot jumper in place for this test. Close MegaTune if it's running, and run the portcheck.exe program. When this program starts, it will scan the available COM ports.
If the port it's scanning is not connected to a working Microsquirt, or it's on the wrong speed, it'll say "No connection made." If it's on the right port and right speed, it will give you the version of the firmware that's on the ECU. Note that some Megasquirt firmware versions will look like earlier versions with this test - for example, 029V identifies it as 029Q. This is for backwards compatibility.
If you get a port where it replies with "S" or something else that doesn't look like a firmware version, this port is probably a fake COM port that echos back everything that's typed.
Let me know what you find.
Re: Serial cable problem
Posted: Tue Apr 15, 2008 1:50 pm
by pommie02
Hi Matt
could you send me a copy of the port checker..
thanks gary
Re: Serial cable problem
Posted: Wed Apr 16, 2008 2:49 am
by pommie02
hi matt
hopefully there should be a screen dump on this...
any ideas
thanks gary
Re: Serial cable problem
Posted: Wed Apr 16, 2008 1:16 pm
by Matt Cramer
If you unplug the Microsquirt and jumper the TX and RX sections of the cable's connector with an alligator clip, see if the results on COM7 go from "No connection made" to "s".
Re: Serial cable problem
Posted: Wed Apr 16, 2008 1:49 pm
by pommie02
Matt
tried that...and still no connection.
i assume that is testing the com lead ?
Re: Serial cable problem
Posted: Wed Apr 16, 2008 1:54 pm
by pommie02
i did the same test with a multi meter...good resistance ..o ohmns.
i guess that rules out the microsquirt ?
Re: Serial cable problem
Posted: Thu Apr 17, 2008 5:57 am
by Matt Cramer
Sounds like you've got a bad cable. If you bought it from us, PM me...
Re: Serial cable problem
Posted: Fri Apr 18, 2008 7:18 pm
by efahl
pommie02 wrote:could you send me a copy of the port checker..
Gary,
I've been putting it into the Megatune installer for a couple of years now, so it's likely that you already have it. Look in c:/Program Files/Megasquirt/MegatuneNNN/ and it should be right there.
Eric