USB Serial Adapters

[JamesC]

I bought an adapter cable from eBay - and it's not working.

It has a USB port on one end - and a male serial port on the other.

I think I know why it's not working - but I'd like some confirmation.

What I have is a "USB serial cable adapter" - where as what I need is a "USB serial port adapter"

The port on the end of my cable is as if you are going to plug it directly in to a modem or whatever - so the wires are essentially crossed over.

What I need is a USB serial port adapter - so that the port is just like what used to be on the back of computers.

To make my current lead work I need some sort of stubby female to male cable with the wires crossing back over.

Does that make sense?

[4600cc]

Your adapter should have a USB connector on one side, and a Male DB-9 on the other side.

<img src="http://www.kanda.com/images/usbserial.jpg"></img>

Bellow is DB-9 MALE
<img src="http://upload.wikimedia.org/wikibooks/e ... png"></img>


Bellow is DB-9 FEMALE
<img src="http://pigselectronics.com/graphics/lar ... jpg"></img>


TO INSTALL (Windows XP):

1) Insert drivers CD into CD-ROM drive.
2) Insert the USB adapter into the USB port.
3) Found New Hardware Wizard windows comes up, click No, not this time, and click Next.
4) Select Install software from specific location (Advance), click Next
5) Click next again
6) Drivers are installed, click Finish.



If you did not follow the above steps, then drivers are not installed for your adapter and it won't work. If that's the case, do this:


1) Go to Start > Control Panel > System
2) Click Hardware tab
3) Click Device Manager button
4) Expand Other devices tree, do you see USB-Serial Controller or something similar? If yes continue with these steps, if no, jump to step X.
5) Right click the USB-Serial Controller (under Other device) and click Update Driver.
6) Click No, not this time, and click Next.
7) Click Install from a specific location (Advanced) and click Next.
Make sure the drivers CD is inside and click Next
9) It will now search and when it finds the drivers a dialog box will pop up, click Continue Anyway.
10) Click Finish.
11) Asking you if you want to restart your computer, click No.


Step X: Verifying if drivers for your USB-To-Serial were installed.
X) Inside the Device Manager, Expand the Ports (COM & LPT) section.
If you see Prolific USB-to-Serial Bridge (COM3), or something similar to that then the drivers are installed.
X.1) To verify if this device is functioning, right click the Prolific USB-to-Serial Bridge (COM3) and click Properties.
Under the device status, read, if it says This device is functioning properly, then you are ok.


<hr>
Now, it might say COM4, COM3, COM2, or COM1, or anything else. As a matter of fact, if you stick the adapter into a different USB port, the COM port number will also change. Thus, if you trying to connect a tuner and it's unable to connect, always check whether you have the right serial port number selected (in the tuner program). To check which serial port number your USB-to-Serial adapter is set to, go to device manager again, and expand the Ports tree. It will say right there in the name the port number.


<hr>
<b>Before you try out the tuner program RESTART YOUR COMPUTER</b>

[JamesC]

Yep - that alllll works out fine.

It just refuses to connect or do anything.

I have it on the table here - the MJLJ powered up via a 12volt adapter... serial cable plugged in... but nothing.

[MartinM]

As far a I know, these adapters are all the same whatever the subtlety of the words to describe them - they mimic the 9-pin DB-9 male serial port connector on PCs or laptops.

I'm not sure what makes you think the wires are crossed over.

If it's long enough, you can plug it straight into the MJLJ, or you can:
- extend its length on the USB side with a suitable USB lead
- extend its length on the serial side with a 'straight-thru' (pin 1 to pin 1, pin 2 to pin 2 etc) serial extender cable - which will of course have one female end and one male end

It's probably not working due to software configuration. Follow Alex's instructions below....

[4600cc]

Why don't you get back to us with this info:

On what port does the tuner program trying to connect?
Which port is your USB-to-Serial set to?

[JamesC]

Here's how the power is connected - the right pins?

<img src="http://www.mintylamb.co.uk/upload/mjlj_power.jpg">

[JamesC]

I'm not silly ) they're both the same.

COM3... I've tried it on COM1 and COM4 also...

[4600cc]

Wiring is right. So this should work:

1) Connect serial
2) Connect power, should be a solid connection
3) Download and install <a href="http://picasso.org/mjlj/?q=filestore2/d ... MJTUNER</a>
4) Run the program
5) Select proper serial port
6) Hit Get Config

either it will get your config or tell you Megajolt is not connected.

If Megajolt is not connected, then it's brocken. Let's try a different program, let's use your Hyper Terminal.


Type hypertrm into the Run box and hit enter.
Type Megajolt into name box and click Ok.
Select COMM port under Connect Using box and hit Ok.
Setup serial porn on the next screen,
BPS = 4800,
Data Bits = 8,
Parity = None,
Stop Bits = 1,
Flow Control = None,
Hit Ok

Type UPPER CASE letter C and/or letter S. Press caps lock on and type C or S. In return Megajolt should send you some rubbish. If it does that, then you're fine, Megajolt is working, if it doesn't do that, then Megajolt is brocken, or your serial port is brocken.


If it didn't work, try to trouble shoot your serial port. Connect to something else for example. If you have a cable, you can make connection to your home PC (using hyper terminal).

[JamesC]

Hmmmmm...

MJTuner reports "ERROR: Could not connect to megajolt on COM3" as soon as I click "Get Config"

Hyperterminal tells me that it's unable to open the port.

So it's almost like something has already got it open.

I have had it where it works fine - i.e. it's able to open the port but get no response. I've tried so many times I am unsure when each thing happened.

[JamesC]

OK - tried it again on my desktop machine - using the USB cable.

This time it set itself up as COM9

This time - it actually thinks about it - and waits a while before throwing up an error.

Hyperterminal now actually allows you to type - but does not return anything.

So it seems that the USB is allowing the port to be open.

[4600cc]

I tried what I preached on my new laptop, Dell B130. Didn't work, SON-O-BISH!!!!


So, I went to BIOS, restart and hit F2 during POST. Under POST Behaviour I disabled USB Emulation, i.e. set it to off. What is that crap anyway, my old laptop didn't have that. So set USB Emulation to off if you have that option, do nothing if you don't have that option.


Then I went to Windows, Device Manager. I tried a different USB port, i.e. stuck my adapter into a different port. It asks for drivers again, so I give it to her. It installs, I fire up MJTUNER, and it connects, I can Get Config, but not every time.

My power connection was not solid!!!!!!!! I had it down with some tape, and it wasn't solid! I put more tape on, and made it so that it's tight. You can open up your box and measure for power on the board.

After that, it worked just fine. I can stick it into first USB or the second, or the third. It works. If program gives you an error that it can not connect, close the program and launch it again.

I went to Runtime Display and it displays it just fine, you can suck on the MAP nipple, map bar goes down.


<hr>

Something that I did made it work.


There are 3 areas.

A) USB Emulation option in BIOS.
B) Connecting USB-to-Serial on different USB port and installing drivers.
C) Going to USB-to-Serial properties (in Device Manager) and from Advanced section unselecting use FIFO buffers check box.
D) Making sure the god damn power connection is rock solid.


<hr>

I still don't know wtf I did, so this step by step is doing something, I don't know exactly which of these steps make it work.


1) Go to BIOS, POST Behaviour, disable USB Emulation. (note this is Dell BIOS)
2) Go to Windows, unplug your USBtoSerial, and plug it into a different USB hole. Follow instructions on the screen to install drivers.
3) Make sure your power connecting is rock solid. If you have to open box and check for power on the board.
4) Go to USBtoSerial properties in the Device Manager, click Port Properties, and click Advanced button. Uncheck use FIFO buffers, click OK.
5) Start MJTUNER again, and try to connect on the proper serial port. Click Get Config. If it does not work, close the program and launch it again, and try again on the proper serial port.
6) It didn't work, stick the USBtoSerial back into the original USB hole you used before, and launch MJTUNER, and try again.



As I said, I don't know which of these steps made the USBtoSerial work, but now it's working, and it's working 100% of the time.

On my old laptop, Dell Inspiron 2600, it just worked.


Let me know how it goes. If it doesn't work maybe we could hook up on MSN messenger and I see what I can do using Remote Assistance. alexc_4600cc at hotmail.

[4600cc]

As I look at it again, for me it was the power. Seemingly it was fine, I use an adapter from some PC speakers, 12.5 VCD, with positive in a hole.

<img src="http://www.qsradio.com/Coaxial%20Power% ... jpg"></img>


I'd wrap around the negative wire and hold it down with some tape. Then I'd stick the positive wire into the hole, and it was tight, but not tight enough. So it wouldn't work.


Now, I just stuck a tooth pic into the hole along with the wire, so it's tighter, and it works.


Definately open up the box and check power on the connector legs as they go into PCB. I just loosen two top screws from each side and the lid opens.

[JamesC]

I changed the port the cable was in - came up as COM10.

No luck with hyperterminal.

Rebooted - changed my USB setting in the BIOS (only have this on my desktop - my Vaio has zero options in the BIOS apart from very basic ones.

Back in Windows... change port again...

Oddly - when I go to the device settings - and go to choose a different COM port - it says theyre all in use - COM1 to 10 - all apart from 9.

Still no luck though - it can open the port - just not communicate.

I am pretty sure my power supply is solid - I've measured all the voltages - all seems to check out.

[4600cc]

They're in use because driver is screwed up. It's a setup problem. I'm pretty sure if I have it here in front of me I can make it work.

[Magnolia]

Sorry you are having trouble. USB -> Serial worked fine for me without any fiddling but I did notice that if I plugged in into a different USB port that the laptop (W2K) wanted to install it again and I avoided that as it looked like a trap.
May I ask where you got the plastic bulkhead connector for your MAP. For some reason I can't seem to find them anymore and can't find my cache.