My MJ unit is complete, I have used a 9v battery during the build to test voltages , but will this be enough to power the unit for a connectivity test with my computer or does it require 12v?
I have it powered with 9v and can't connect to it so far.
9V enough?
Moderators: JeffC, rdoherty, stieg, brentp
9V ok
9V works for me.
1) Verify that you have a straight through serial cable, pins 2 & 3 on both ends are same.
2) Put a jumper between 2 & 3 on the end that you would plug into Megajolt. Launch Hyper Terminal from Windows Aaccessory -> Communications menu. Go to File -> Properties and verify COM port you are using and at 4800 baud, handshaking - none.
3) Now because of the jumper, anything you type should be echoed to your screen. If you don't see what you typed and have followed directions above, then you probably have a conflict between devices using your serial port or you have selected the wrong COM. If so, go to Settings ->Control Panel -> System -> Hardware -> Device Manager and look at how your COM ports are assigned.
If it echos Ok, then you might have some kind of Java install problem. Review the instructions and make sure you installed correctly.
PS: Also make sure your chips are plugged in with matching notches.
1) Verify that you have a straight through serial cable, pins 2 & 3 on both ends are same.
2) Put a jumper between 2 & 3 on the end that you would plug into Megajolt. Launch Hyper Terminal from Windows Aaccessory -> Communications menu. Go to File -> Properties and verify COM port you are using and at 4800 baud, handshaking - none.
3) Now because of the jumper, anything you type should be echoed to your screen. If you don't see what you typed and have followed directions above, then you probably have a conflict between devices using your serial port or you have selected the wrong COM. If so, go to Settings ->Control Panel -> System -> Hardware -> Device Manager and look at how your COM ports are assigned.
If it echos Ok, then you might have some kind of Java install problem. Review the instructions and make sure you installed correctly.
PS: Also make sure your chips are plugged in with matching notches.
Thanks for the reply.
Thanks for the reply.
I have managed to get it connected now , and it seems to work fine! Very happy , MAP reading 99 which seems good to me.
I think it could have been software related as I hadn't copied comm.jar across properly?
I have had to use the mjtuner software as the adist-mjtune software only provides options for com ports 1-4 , and for some reason my software has assigned the com port to com6.
In the end I stole the batteries from the DVD remote and wired them in series with the 9V to provide 12V!
Anyway , I'm up and running , I have all the bits so all that remains is for me to fit it all in the car!
Cheers
Bill
I have managed to get it connected now , and it seems to work fine! Very happy , MAP reading 99 which seems good to me.
I think it could have been software related as I hadn't copied comm.jar across properly?
I have had to use the mjtuner software as the adist-mjtune software only provides options for com ports 1-4 , and for some reason my software has assigned the com port to com6.
In the end I stole the batteries from the DVD remote and wired them in series with the 9V to provide 12V!
Anyway , I'm up and running , I have all the bits so all that remains is for me to fit it all in the car!
Cheers
Bill
Well unfortunately it's not
Well unfortunately it's not working anymore. I went away for a few hours , and when I tried to connect again it won't work.
I have been trying to change the settings since and have probably made things worse for myself. However I have reinstalled the usb cable software a few times and even done a system restore , so it should be back to how it was.
Using hyperterminal , I can connect through the com port. However , I cannot type in any commands , as I could before. Also , if I connect the power to the MJ whilst connected with hyperterminal , a character comes up on the screen.
Any ideas?
I have been trying to change the settings since and have probably made things worse for myself. However I have reinstalled the usb cable software a few times and even done a system restore , so it should be back to how it was.
Using hyperterminal , I can connect through the com port. However , I cannot type in any commands , as I could before. Also , if I connect the power to the MJ whilst connected with hyperterminal , a character comes up on the screen.
Any ideas?
Serial port blues
You noted a couple interesting things in your messages.
1) You had to use other tuning software because COM6 got assigned.
2) You are using a USB<->Serial adapter with drivers.
Some people report problems using converters. It would be nice if the DIY stuff was all USB compatible since the basic RS-232 serial connections have become obsolete and are not even on a lot of machines anymore. I have a desktop machine that is port COM1 whenever I plug a cable into the same RS-232 connector. My laptop only has USB ports although its docking station has a standard serial connection. When you install drivers, they determine the functionality. Typically, when plug-n-play sees a device plugged in, it determines if it has seen it before. If so, it silently loads the driver. If not, it attempts to find a driver notifying you of the process. For my laptop, I bought a new $12, including shipment, USB adapter from EBAY. When I connected it, I provided the accompanying disk when prompted and it worked fine. Device manager showed me that it was using COM4. I do not know why it chose COM4 as only COM1 is in use as an integrated modem. The bridge works fine as long as the software is looking for COM4. The second time I plugged it in, it wanted to re-install again. I pondered this a moment, then cancelled the install and moved the connector to the other USB port that I had used the first time. It connected instantly without any further installation. So, the driver is not smart enough to determine that the device is the same but on a different port. My driver installed with port settings as 9600 baud, 8 bit, no parity, 1 stop, and flow control None. This works fine.
You shouldn't have to have mj powered up to install the bridge but you should have it powered up before you attempt any communication with the bridge.
Not sure it is a good idea to connect batteries with different cell configuration together. 9V sb adequate. My kids depleted my 9V supply so I used 6 slightly used AA in series the night that I built mine. They measured 9V, less than a good 9V battery.
Proably not much help here but that's about all I know...jah
1) You had to use other tuning software because COM6 got assigned.
2) You are using a USB<->Serial adapter with drivers.
Some people report problems using converters. It would be nice if the DIY stuff was all USB compatible since the basic RS-232 serial connections have become obsolete and are not even on a lot of machines anymore. I have a desktop machine that is port COM1 whenever I plug a cable into the same RS-232 connector. My laptop only has USB ports although its docking station has a standard serial connection. When you install drivers, they determine the functionality. Typically, when plug-n-play sees a device plugged in, it determines if it has seen it before. If so, it silently loads the driver. If not, it attempts to find a driver notifying you of the process. For my laptop, I bought a new $12, including shipment, USB adapter from EBAY. When I connected it, I provided the accompanying disk when prompted and it worked fine. Device manager showed me that it was using COM4. I do not know why it chose COM4 as only COM1 is in use as an integrated modem. The bridge works fine as long as the software is looking for COM4. The second time I plugged it in, it wanted to re-install again. I pondered this a moment, then cancelled the install and moved the connector to the other USB port that I had used the first time. It connected instantly without any further installation. So, the driver is not smart enough to determine that the device is the same but on a different port. My driver installed with port settings as 9600 baud, 8 bit, no parity, 1 stop, and flow control None. This works fine.
You shouldn't have to have mj powered up to install the bridge but you should have it powered up before you attempt any communication with the bridge.
Not sure it is a good idea to connect batteries with different cell configuration together. 9V sb adequate. My kids depleted my 9V supply so I used 6 slightly used AA in series the night that I built mine. They measured 9V, less than a good 9V battery.
Proably not much help here but that's about all I know...jah
Serial Port
I have just built a Megajolt and I use a laptop with a usb to serial convertor. I had to change the assigned port of the adapter to COM1 to work with Brett's software. But I have found that the mjtuner_0.2.2.1260_preview is easier to use and also works fine with the convertor.