2 group DIY transmit modem

[terryo]

thanks for the info. i still have an old laptop that i could use. how do i obtain the modem??

[SprinterTRD]

You cannot get them anymore which is the point of this thread - you have to make the electronics that is linked in the second post

[CamB]

I've now made a second one, so have a spare.

(Edit) also have now tried with a Prolific-based USB - serial cable which does not work well with DosBox and Windows 10 (lots of framing errors). Wouldn't connect to the ECU.

I also retried the FTDI cable - DosBox actually only gives framing errors when the ECU is not connected. I am still not brave enough to use it for tuning (I don't mind reading with errors but not too keen on writing).

Windows XP remains the proper solution.

[Stephen Dean]

I made a clock generator/transit modem that works great.

Mine has an onboard +5V voltage regulator with a heat sink bolted to it and is wired to a +12V automotive cigarette lighter plug.

I even went overboard with the coil and crystal sizing, and it has no oscillations or issues whatsoever. I also added a cooling fan and grill for both ends. Runs cool as a cucumber!

I am running Windows Xp on an old dell, with a Motec factory PCI cable 63003 and then a straight through DB9 cable.

Graphics are great as well as response to commands.

I think I bought two of everything I used on the transit modem, so it could be duplicated or repaired exactly.


I am selling this clock gen/transit modem, two great working CEM-3D 2 group ECU's, one V8 engine harness, and a perfect working hand controller.

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[Turbofreak]

More pics

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[Turbofreak]

Hand controller working

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[trofimovich]

Hello. I assembled a schema on the breadboard and it started right away from the first start.
Thanks to MoTeC for the scheme!
The circuit works from the laptop + 5v and ECU.
The photo shows the chip 7805 but it is not powered.
Greetings from Russia.

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[Ppagr1]

Hi Turbofreak,
I'm interested in buying a transmit modem and hand controller if you have any for sale. I've got an old 2 Group that i'd like to get running again
Could you please let me know if you have any for sale?
Cheers
From
Pete

[CamB]

I have a spare modem I made - works with mine (and doesn't need the Motec PCI cable either). Based in NZ. You need to make sure:

- the ECU is one that you can connect to by PC (I understand some older ones can't?)
- you have an older laptop you can use to connect - preferably Windows XP (or older!) and with a serial port as USB-serial converters aren't necessarily going to give consistent results

[Ppagr1]

I have a spare modem I made - works with mine (and doesn't need the Motec PCI cable either). Based in NZ. You need to make sure:

- the ECU is one that you can connect to by PC (I understand some older ones can't?)
- you have an older laptop you can use to connect - preferably Windows XP (or older!) and with a serial port as USB-serial converters aren't necessarily going to give consistent results

Thanks CamB,
My ECU is PN CEMECU-MAG, EPS 2.5 C3.
It's a pretty early one and other threads say that anything earlier than V3 probably won't connect to a PC.
I was keen to give it a shot anyway but might just hunt for a hand controller only instead, that way the transmit modem can go to someone who will definitely get some use out of it.
I'll keep hunting for any hand controllers out there for sale - please pm me if you have one
Pete