fuel consumption isnt a very good use for this product. Buy a trip puter if u want that. What id like to see it capable of logging is

Spark advance (from TFI)
Knock Sensor
HEGO
RPM
MAP/MAF
TPS
Road Speed
Gear

Being a serial conection isnt much use for people, as not many laptops have serial conections any more. 1394/usb may be a better (yet increasingly more expensive and complicated option).

you can always buy a serial to usb convertor set you back about 50bux, cheaper option then redesigning the controllers to work with usb. Was doing some research and found a product similar to yours but without the two lince lcd, snEEC, will upload live feed to laptop maybe you can reverse engineer the software for that (freedownload off racesystems site) and use some of the code to get some live feed display software to work with yours nless you already have

Yeah I am using a USB to serial converter I got of E-bay ($12) to download the data now. I looked at USB but it is pretty complicated and you run into issues with drivers (they all have to be registered with a central database =$$$) and complicated software at both ends. There are ways around it but still hard. The microcontroller I am planning on using has serial built in. I don't need the speed anyway.

What about outputs? Currently I am planning on (2x) 1Amp PWM outputs (0-12V) and a digital out. I was thinking people could use them for Nitrous triggering, waterspray/injection, possible electronic boost control?

They would be configured to use a 3D lookup table based on any two inputs to the datalogger.

Software is not too much of a problem since serial is pretty easy.

The ignition advance is interesting - I will look into that

Starting to see elements of an air/fuel controller there... i.e. taking an input from any given sensor (in AFC case, MAF) and modifying the signal before it reaches EEC...

Water injection is a very cool idea. Currently mine is activated by a pressure switch in the vac system, would be good to have it come on at a pre-determined rpm/tps condition. Also easy to control NOS i.e. predetermined TPS/RPM range.

Regarding timing signal, I think all of the SPOUT/PIP information is a sine wave as the EI system pre-processes this before communicating data to EEC.

You can get RS232-USB micros that use a bog standard (ie. cheap/free/already certified) driver, and appears as a serial port to windows/linux, so no software mods needed (either PC or PIC).

Here's one example: http://www.ftdichip.com/

Or why not use intake air temp and MAP (or knock!) to trigger water spray, then you are only using it when you really need it. In regards to the interceptor you could use it for that but creating a frequency varying signal requires very accurate timing (but hey its all possible).

In other news the development of the current version is going well. I tidyied up some of the inputs and worked out some of the electrical gremlins. Also my mate and I had a chat and worked out a spec for the PC software so we will see how that goes. Also got speed measurement and PWM output working.

With the USB/Serial thing, I am going to keep it as serial since at the moment Serial requires connecting 3 wires where USB at the very least requires a 30pin+ chip with all the associated issues involved with routing circuit board tracks. The idea is to sell this as a kit that people would solder themselves so I am trying to keep it simple as possible and only using pin-through packages not surface mount.

Also firmware updates would come through the serial port so some USB-serial converters dont support certain serial functions. I really want to make it USB too but it will have to be in a later version.

In other news the development of V2.0 is going well and it looks like there will be 256K of EEPROM on the board for a 3min log (at full rate). I have found through my own testing that it really needs to have some form of internal logging since generally you don't want your laptop in the car when you are throwing it around!

BLOODY good work mate, keep it up