[josemapiro]

Originally Posted by skybolt

I chose video out because it was the simplest, easiest way to display the output. The Raspberry Pi cannot replace the arduino, as a raspberry pi isn't a real-time processor and cannot be guaranteed to measure each speedometer tick or fuel injection pulse, not to mention that no measurements would take place during a boot process.

On the other hand, the arduino is very, very limited it its ability to display video. As hard as I tried, I was only able to get limited text, which rapidly exhausted the available memory necessary to run the aquino routines that measured fuel and speed pulses.

The combination of a raspberry pi and arduino can be made very, very small. I originally used a raspberry pi zero which is very small and can be attached to an mpguino with electrical tape. I chose a raspi 3 because I preferred the video performance. With a slightly larger raspberry pi I can mount a much tinier arduino pro mini, which is about the size of two quarters.

You aren't required to display this on a head-unit, but should you prefer to do so, you simply plug the raspberry pi video out to an open video port on your stereo. If you want to use an embedded screen like in my example, you can do that instead. It's very flexible and not limited to a single hardware architecture.

I can't continue work on miniaturizing the arduino and attaching it to the pi until I create the car interface board that are already on MPGuino boards -- the resistors, capacitors, diodes and voltage regulator. Once I've done that (and I have a working breadboard version, so I should be able to do this part shortly), I can start in on putting the new code base on a Pro Micro, and you should be able to use any display type you want.

Truth be told, hooking the mpguino up to your car is going to be a lot more difficult than attaching a video cable to your head unit, even when you factor in supplying power to the raspberry pi.

Okay, I understand, I'm waiting for further development of the project.

Thanks
José Rodrigues