MPscan issues

[miniman82]

First I am not a computer genius, so bear with me.

I can't get MPscan to work. I have a usb>serial adapter from Gigaware, bought it from Radio Shack. It works fine for my Megasquirt, so I know it's good. MPscan doesn't seem to like it though, is it required to have an FTDI adapter for this program? Problem I have is MPscan will open COM3, but will not read anything from the car. I have it hooked up from the RX of the serial port to the pink wire of the SCI connector on the car. All it will do is tell me to cycle power on the car, or give me a unhandled exception error.

Help!

[wowzer]

the ftdi cable is HIGHLY recommended vs a generic since the latency can be adjusted programmatically as well as the tx/rx signals can be inverted via the chip eeprom. otherwise i "think" you need to figure out a way to invert the signals separately. not quite sure about this. the electronics geeks are going to have to jump in on that. i've never used a generic usb cable, always the ftdi.

couple things for you to report. when you start mpscan with the cable connected what shows up in the lower left hand status bar? can you show some screen shots of it and/or the message you get? also, there is a file that is created (mpscanport.txt) that provides some limited connection info. post that up also. if you have windows vista or higher it should be in a directory called something like "C:\Users\Morris\AppData\Roaming\MPScan"

[ShelGame]

First I am not a computer genius, so bear with me.

I can't get MPscan to work. I have a usb>serial adapter from Gigaware, bought it from Radio Shack. It works fine for my Megasquirt, so I know it's good. MPscan doesn't seem to like it though, is it required to have an FTDI adapter for this program? Problem I have is MPscan will open COM3, but will not read anything from the car. I have it hooked up from the RX of the serial port to the pink wire of the SCI connector on the car. All it will do is tell me to cycle power on the car, or give me a unhandled exception error.

Help!

It won't work. The SCI outputs are inverted logic (IE, 0V is a logic 'High' and 5V is a logic 'Low). The FTDI chip is the only one I've found that will allow you to invert the IO logic levels with a software flash.

[miniman82]

Funny you should mention:

I thought I'd be needing an ALDL cable for some reason, because I assumed I'd be using an OBD port for this. I built this circuit, which is for GM interfaces, but looking at it maybe it will work here as well?

http://www.gmtuners.com/eprom/DIY.htm

[ShelGame]

I don't think so. The ALDL Mux's the Rx and Tx together. We use bi-directional communications.

[miniman82]

I could mod the circuit for bi-directional comms and give it a shot.