MPGuino release one workspace

[ptsmith24]

Originally Posted by forgottenmindset

My guess is that the change from the usb voltage to the car's voltage is different and thus the screen is out of sync. That happens to me too, but you can just unplug it and plug it back in several times and then that should work, but if not, wait a few seconds then do it. If still no, pull the power jumper out of the duino with the power cord still in, and put it back in.

Thanks. It did it again to me when I changed ground location. A couple power cycles helped. The MPH is closer with the foreign car estimate of 8204 (I think). I'm going to try and find the vss and injector numbers online. If anyone has a good source, please post it.

[dcb]

Please just unplug it from your laptop, wait 20 seconds and plug it into the car. Bouncing the power a lot CAN screw up the chips flash/eprom memory, so be real deliberate when hooking up the power, and wait at least 20 seconds for it to come to life before disconnecting it, unless there is smoke of course .

8208 should work, dunno on the injector numbers.

[ptsmith24]

Originally Posted by dcb

Please just unplug it from your laptop, wait 20 seconds and plug it into the car. Bouncing the power a lot CAN screw up the chips flash/eprom memory, so be real deliberate when hooking up the power, and wait at least 20 seconds for it to come to life before disconnecting it, unless there is smoke of course .

8208 should work, dunno on the injector numbers.

Ok, will do. I will get around to calibrating it tomorrow. In the meantime, I'll use the 8208 for the vss pulses/mile. I'm on that site for the injector flow rates that someone posted before. Does anyone have the conversion from lbs/hr or cc/min to usec/gallon? It's temperature dependent, no?

[ptsmith24]

Another thing, what are the temperature limits on the LCD and the arduino board? It's been pushing close to 100F today and the next few days. More than that in the car, obviously.

[ptsmith24]

I finally got it all working. The pulses/mile seems to be accurate (distance is within 0.01 mile over 3 miles) But, the speed jumps a good bit (for example, going 20, it jumps 15-25 and everywhere in between). The usec/gallon must be way off (by a factor of 3 or 4, maybe?) The mileage at 45MPH is showing 7MPG (should be 3-4 times that). From my wiring diagram for my ECU, it looks like 2 of the injectors fire at the same time, alternating with the other 2. Could that be affecting that number? I put in an initial usec/gallon of 296052631 (assuming 6.25 lbs/gallon, 19 lb/hour injectors). I'll go ahead and put in a wiki entry with these numbers and put a note that I'm still calibrating.

edit: another note: be careful with the wiring in older cars. I broke my VSS lead in two and had to reconnect that before splicing in again.

[ptsmith24]

I got it a whole lot closer on the usec/gallon by NOT dividing by the number of injectors (4). Any idea for that cause of that? I'm using 1165263158 usec/gallon and the instant mileage is pretty close. I'll verify that number over the next 2+ fillups (since I haven't filled up since I've installed it in my car). I've updated the wiki with the newest number until I can verify the actual gallons used (or reasonable estimate, anyway).

[dcb]

It is what it is

I was going to suggest upping the usPerGallon proportionally, but it looks like you figured it out

[wagonman76]

I agree, it is what it is. I like to try to get a good ballpark number for starters.

The only thing I can think of is maybe his injectors are controlled on the positive side, with a common ground. So say if the injectors happened to be fired one at a time, itd be 1 injectors worth of fuel per detected pulse if the ground is common. If thats not it, then who knows, no biggie.

Mine are controlled on the negative side, 3 at a time, 2 banks on separate circuits. I tap into the ground on one of the banks. So with one detected pulse I get the fuel from the 3 injectors on one bank, plus the fuel from the other 3 injectors whose pulse I do not detect. So 6 total per detected pulse.

BTW I just got my 2nd mpguino wired up, minus the 4 wire connector. I decided to try the Freeduino kit. Piece of cake once I used the process of elimination to figure out what everything was, and easy to solder. My board with buttons is a near perfect fit, I got it from a scrapped flat screen monitor and sawed off the end of the board with the 4th button. I also eliminated the other circuit board assembly and fit the diodes, resistors, and transistors right across the top of the board between the pins, which are just cut up paperclips.

Wow what a difference with the correct display. It seems quicker and clearer, and I like how it actually shuts off all the way. It sure is bright though, so I added a 21 and 10 into the brightness list to get some darker settings to try once it goes in the van, then we will see what setting we really need. The wife said blue would be cool, since it matches her stereo. I have another KF8040 enclosure from work, but Im not sure if Im using it yet. When she gets back with the van tomorrow, Ill see what kind of arrangement would be best so it can be easily seen but not block anything.

[ptsmith24]

I guess I shouldn't post so many so many consecutive times with problems. I should at least try and work through them a little more first. However, I do help it helps people building it for the first time. I've considered helping by adding a Troubleshooting section to the Wiki. I can scan through this thread and pick out issues and their solutions (probably just with the build and setup..not with the code itself). It's kinda tedious to remember what page a certain tip was on with a 31+ page thread. I know that's partially my fault for not copying/pasting elsewhere when I found what I needed instead of having to re-find it. But, it would have saved me some time to begin with by having a central place to look first. What does everyone think?

[dcb]

Some sort of FAQ page on the wiki would certainly be useful. Any member can do it.