[t vago]

Originally Posted by skybolt

Right now I'm working on how to deploy a sketch to the arduino from the pi -- FTDI is out (an extra board is undesirable, also don't want to collide with tx out); ICSP is out (don't want to have to add a capacitor and extra crystal), I think I can do it if I send a 0 (or low) to the rst pin. This would be first level of control from the pi/phone.

I am wondering if you could use I2C to talk with the MPGuino, since I have now coded in a fully functional I2C interface (it's also called TWI). That would be bidirectional, and you could code any sort of interface on the pi end.

Originally Posted by skybolt

Should be easy to have the pi send signals to the arduino (such as A3, 4, 5 to ground). Long term (i.e. future plan with no idea of work involved) would be to scoop serial rx pin for string commands from pi.

I did some experimentation some years ago with serial Rx and the Arduino platform. I was somewhat less than impressed, as I discovered that the Arduino would randomly drop characters for no apparent reason. I might revisit the code I wrote back then, and see if I made any mistakes (which is entirely possible).

Originally Posted by skybolt

"subtitle":"drag stats: 0-30 MPH in 0.000 sec, 0-60 MPH in 0.000 sec, 0.000 sec to 0.000 mi @ 0.000 MPH, engine output 0.000 HP @ 0.000 MPH",

As you know this is scrolling off the screen to the right. I've given up trying to insert a BR or CRLF into the display text; I will toy around with moving some drag stats to the middle graph, leaving some at the bottom. Probably distance stats in the middle/mileage section, fuel usage drag stats in the 3rd section.

Is the pi code failing to properly interpret any <BR> or CRLF combination within the quotes?

Originally Posted by skybolt

const unsigned int pAddressInjectorCount = pAddressRefFuelPressure + byteSize(pSizeRefFuelPressure);
const unsigned int pAddressInjectorSize = pAddressInjectorCount + byteSize(pSizeInjectorCount);

As near as I can tell, mS/Gallon is calculated/modified by numberOfInjectors. Why is this there?

MPGuino reads the signal from only one injector for an engine, but modern port fuel injection engines have one injector per cylinder. The numberOfInjectors parameter tells MPGuino to account for that in its calculation of usec/gallon.

Originally Posted by skybolt

I've been going back to the old method of 1 injector and my old mS/Gallon. Fuel pressure and injector size appear to have no effect on my setup, is this for future hyper-precise calculations?

This is partially for Chrysler products, but yes, it can be used for hyper-precise calculations. I remember that josemapiro reported last year that MPGuino calculation of usec/gallon wasn't working, and that I traced it to a couple of coding faults that I corrected and made available with the 20170116 release. What version of MPGuino are you using? I justed tested this feature and it works well for me.

Originally Posted by skybolt

Can I ignore this for now? If not, I have 650cc injectors, is the size (246cc default) the maximum or a different flow value?

It should accept up to 999.999 cc/min injectors. I've just now identified another bug that prevents it from accepting 1048.575 cc/min.

But you can also ignore it and enter in the usec/gallon figure directly.

Originally Posted by skybolt

scratchpad
BGLower
BGDSize
FE Filter
FE Time Period

What's the significance of these parameters?

BGLower - this is the lower speed parameter for the FE vs. speed graphs. Any vehicle speeds lower than this parameter will be ignored.

BGDSize - This is the width of each speed bar on the FE vs. speed graphs. If BGLower is set to 25 MPH, and BGDSize is set to 5 MPH, then Bar 0 corresponds to 25 MPH <= speed < 30 MPG, Bar 1 corresponds to 30 MPH <= speed < 35 MPG, and so on.

FE Filter - enables or disables the window filter function for the Instant Trip variable. It smooths out the jumpiness associated with taking 0.5 second samples and the inherent jumpiness of OBDII fuel injection systems that vary fuel delivered in order to make the pre-cat O2 sensor jump around stoich. This window filter is only applied after Instant Trip updates Current Trip, Tank Trip, FE vs Time (if compiled), FE vs Speed (if compiled). Accel test and coastdown do not use Instant Trip at all.

FE/Time Period s - This is for FE vs. time graphs, and is the width of each time period that is graphed.