MPGuino release one workspace

[dcb]

and it certainly isn't easy to test all the permutations of inputs and sleep-ness

[Jamdat]

Hmm, that is a small current draw and I suppose it is a lot of work. I was just thinking about people like myself who sometimes park their cars for several weeks at a time and might have battery issues.

Perhaps sleep could be implemented through a user-selectable menu option. Write the current RAM to EEPROM and basically shut down. Then some signal (keyed power?) could bring it back to life when the car is started again. I wish I had some better 'C' chops to try and tackle this.

[nickdigger]

not sure if the latest release has data restore from eeprom, but you dont need to dump the entire RAM --- only the current & tank data structures (64 bytes each, or whatever).

if you're storing your car, shouldn't you unplug the battery anyways? your clock & radio & alarm will drain it more than the 'guino.

i disagree that waking from sleep would be detrimental to microsecond-level data collection. Over a full tank run, each wake-up would cause you to lose, at worst, 0.5-sec of cranking data. In a word: "negligible". Sometimes, depending on your wheel position, simply turning the key "On" will trigger a VSS change, and thus, a wakeup. if you also have the habit of waiting 2 sec for your fuel pump to prime, your guino will be wide awake & ready for pulses before the cranking starts.

Anyways, the 20ma is also negligible. I would just do the auto save/restore from eeprom, and just unplug it if power drain is ever a concern. I'd implement the save/restore anyhow, moreso to prevent total data loss from unexpected resets or whatnot.

[JellyBeanDriver]

Originally Posted by dcb

That one looks kinda old, many changes since then. Current schematic is here:
//opengauge.googlecode.com/svn/trunk/mpguino/mpguino.png

Is this one still current? I'm just getting into this and could use not just a MPG meter but a more accurate speedo as I upgraded to larger brakes/tires. Thinking of laying out a PCB this weekend (single sided) so I can start playing and I want to use a skinnier LCD but want to make sure whatever I do is at least current.

TIA,
Dave

[steffen707]

I apologize if my questions are not suppose to be here, but.

I bought a mpguino about 6 months ago, finally found the car i want to put my vx swap into.

Do you have the link for the enclosure from radioshack, i can not find it again?

And more importantly, do you know what the civici vx or 97 honda civic dx microsec/gallon value is? I know there is a calibration information page on the mpguino wiki, but these cars are pretty common, thought maybe somebody already had this value. I can't wait 200 miles before I start checking accurate figures.

[dcb]

There is a table of car settings here, the community has to provide the details for their cars since I don't have access or time to do so:
...f Car Settings - EcoModder

if your car isn't listed, please do some calibrating and add your findings for your vehicle to the table.

Also, please consider starting a wiki page for your model that has some hookup point pictures, i.e. Metro - EcoModder and adding a link in the car settings table.

[steffen707]

sweet got my mpguino all set up and its working!!! One thing i'm confused about though, is when new software is released, how do i get it put on my unit:? there isn't a usb or serial port on it????

The pre-assembled one i bought looks like this
http://opengauge.org/mpguino/
and has no usb header

the do it yourself kits that have usb headers look different and have buttons in different locations???
http://spiffie.org/kits/mpguino/assemble.shtml

I'm confused.

[Magister]

Cost saving I guess because the FTDI chip is expensive. To update the firmware you can pop up the ATMEGA and put it in an Arduino then do the firmware upgrade.

Originally Posted by steffen707

sweet got my mpguino all set up and its working!!! One thing i'm confused about though, is when new software is released, how do i get it put on my unit:? there isn't a usb or serial port on it????

The pre-assembled one i bought looks like this
http://opengauge.org/mpguino/
and has no usb header

the do it yourself kits that have usb headers look different and have buttons in different locations???
http://spiffie.org/kits/mpguino/assemble.shtml

I'm confused.

[Jamdat]

Can somebody help me make sense of this paragraph from the wiki?

Changed programming method to isp (instead of bootloader) and using the following fuses after much experimentation: lock 0x2b , do not allow any spm commands from anywhere, should help prevent flash corruption. efuse 0x07 , change reset address to 0x00, min bootsize (just in case) hfuse 0xdd , 2.7v brownout detection, had lots of problems with 4.3v setting, i.e. unit resets when starting car. lfuse 0xef , maximum delay on power up.

I know about fuses on the atmega (although they are confusing) and I'm trying to follow along with the Engbedded AVR Fuse Calculator, Binary-Hex converter, AVRDUDE manual, and, most importantly, the ATMEGA328 datasheet. There are pages and pages describing which fuses do what and the myriad of options available for each but I'm getting very confused by the above paragraph.

If I convert the low fuse from hex to binary for example (0xEF -> 11101111) I look on page 29,30, and 300, and I see we have selected a low power crystal (8-16MHz) with fast rising power and 4.1ms delay. If this is true, why do we have a 20MHz crystal and why are we saying this is 'maximum delay on power up'?

Same with high fuse (0xDD -> 11011101). 512 word bootloader section, which is not the 'min bootsize (just in case)'.

Finally, extended fuse (0x07 -> 111). This has brownout disabled, while you say it is at 2.7V).

The lock bit (0x2B -> 101011) is the only one that makes sense as it prevents all SPM writing to the application and bootloader section but doesn't prevent further programming.

I said previously that fuse programming is a bit confusing, but I've spent two days looking over this and I simply don't see how these fuses correspond to the descriptions that are given. I have a blank chip sitting in front of me and I would like to program it for my MPGuino, but if that paragraph describes things accurately, then I'm understanding something horribly wrong and I would like to be corrected.

A small explanation from somebody would be much appreciated!
Thank you.

[mjspiess]

I've had my MPGuino for almost 2 years now & it currently has v0.75 on it. Every now & then the speed will jump all over messing up the mpg calculations. I've calibrated it and what-not, but it still does it... I was hoping a software update would fix this. What's the newest version that will fit on a 168 chip? I've read where some people have v0.82, but I can't get it small enough to fit. Any advice would be greatful! Thanks!