This is my ARM board for the new comers to this thread. Arguably the most powerful embedded processor for EFI.

http://www.mikroe.com/easymx-pro/stellaris/

The Hard ware cost  of $200 pales into insignificance when one is going to spend months writing the software.

The idea here is to develop and open source EFI like Megasquirt but with modern processors.

ADC (Analog to Digital Converter) module is available with a number of ARM MCU modules. ADC is an electronic circuit that converts continuous signals to discrete digital numbers. ADC Library provides you routines that work with the module.

Library Routines
ADCx_Init
ADCx_Init_Advanced
ADC_Set_Input_Channel
ADCx_Get_Sample
ADCx_Read

Here are three of the routines. The ARM provides 24 channels of analog to digital but we don't need to use them all at first. This an EFIS as well as an EFI. We will use one for RPM along with a very simple analog tach hardware modules as it is quick and simple way of doing it.

Here are the last two routines. This kind of support built in to the
MikroPro compilers make writing an EFI/EFIS system rather simple. The
third major section deals with shipping the numbers out to a cockpit
display using one of the three or four USB ports  on this board.
This board has more USB ports than my note book computer :)

An EFIS is basically reading engine parameter sensors and converting 0 to 5 volts to digital numbers and sending the information out to a small tablet mounted on the instrument panel for display. Combining that with the information from the EFI system gives a very comprehensive over view. There are dozens of small tablets on the market most of them have built in GPS receivers. Some have built in  solid state attitude gyros. Some of the larger cell phones would also work.

Next we will discuss the USB routines.

Paul Lamar

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