OBD MPGuino gauge

[jmilk]

Originally Posted by ishiyakazuo

I didn't look at the LCD power ratings, but do backlights use that much still? I guess 1.5W isn't that bad when hooked up to a car battery, but I'm a little surprised -- I just wrapped a project a few months back with an ARM7 @ 48MHz with USB, an FPGA and a 2x16 LCD (non-backlit) and the entire setup amounted to about 1W off of a +5v supply.

Pretty close, depending on size and backlight. I have a box of white-lit 4x20 here that draw up to 320mA at 3.4V. That's a 1.6W at 5V, and we provide a 0.5W heating element. If you don't like the heat or the 1/2W R, you can always PWM them over a TIP120 with 10k to base at max 60% duty-cycle (which is an analogWrite ~160). The 10k limits IB to 0.5mA, which the darlington multiplies by 1,000 to 500mA Ic. LEDs tend to be pretty proportional in their relationship between duty-cycle and I. Good idea to reduce Arduino's PWM scaler tho, as the 400Hz default still does 15ms...

ok, but I'm rambling.

[jmilk]

dcb, you're in the Chi'burbs? I'm far NW currently, thankfully not quite Rockford.

Originally Posted by Magister

Note also that you must be CAN compliant to plug something on your CAN bus, unfortunatly the AtMega is not qualified for C&S CAN Conformance like the AT90CAN.

Your PC isn't "CAN compliant" either, but you can connect it to your car through an appropriate interface. The MC2515/MC2551 combination forms the interface to the ATmega (or any other SPI-capable uP you like). "Compliance" isn't really a deciding factor as much as "conformance". You can be conformant without being compliant... in the end, things will work just fine, but you don't get the pretty stamp from the standards body.

[ishiyakazuo]

Originally Posted by jmilk

dcb, you're in the Chi'burbs? I'm far NW currently, thankfully not quite Rockford.

That's amazing. What is it about Chicagoland driving that makes this project appeal so much?
If there's enough of us in the area, might be nice to meet up to do some kind of pooling of resources someday.

[jmilk]

Originally Posted by ishiyakazuo

That's amazing. What is it about Chicagoland driving that makes this project appeal so much?
If there's enough of us in the area, might be nice to meet up to do some kind of pooling of resources someday.

Another FIB, just noticed your location. Frankly, I think it's the flat terrain eco-driving in its purest form.

I've lived in this area 15 years. NW up and down I-90, then a few years W on I-88 and now back far NW on 90. Worked downtown a few years... Metra gets great gas mileage.

Could anyone who lives closer to Elgin explain the strange phenomenon I dubbed "Elgin Zone"? Speed limit west of Elgin is 65, and everyone sticks close to it. Speed limit east of Elgin is 55, and everyone seems to go 75+. What gives? Remember the Kennedy Funnel? Eight toll-lanes two 2+1 lanes and daily parking lots...

[jmilk]

Have you seen this?

[dcb]

Sure, lets hook up. I have to say I'm reminded a little of a Johnny Mullet post re: ohio gathering

Originally Posted by Johnny Mullet

I cleared it with my wife and she said, and I quote..................

"You can have your Nerd-fest 2008 if you like."

I would have loved to get to the renewable energy fair in Oregon, IL, but the timing didn't work out.

[ishiyakazuo]

Originally Posted by jmilk

Another FIB, just noticed your location. Frankly, I think it's the flat terrain eco-driving in its purest form.

I've lived in this area 15 years. NW up and down I-90, then a few years W on I-88 and now back far NW on 90. Worked downtown a few years... Metra gets great gas mileage.

Could anyone who lives closer to Elgin explain the strange phenomenon I dubbed "Elgin Zone"? Speed limit west of Elgin is 65, and everyone sticks close to it. Speed limit east of Elgin is 55, and everyone seems to go 75+. What gives? Remember the Kennedy Funnel? Eight toll-lanes two 2+1 lanes and daily parking lots...

I've been in the 'burbs my whole life. Metra does get amazing mileage My office is right by one of the stations, so I'm looking to get a house on the same train line when I move next.

The Elgin Zone phenomenon is so true, but if I had to hazard a guess about why it happens, it probably has to do with population density -- west of Elgin, the density drops tremendously. With more people, people think they can get away with more.

[jmilk]

I just got a nice little box from Microchip Thailand. Three each MCP2515 and MCP2551 in DIP. Getting ready for vacation, so I don't know how much time I'll have 'till October, but I'll try to get a couple of my RBBBs to talk to each other over CAN on protoboards this week. Wheee!

[ishiyakazuo]

Originally Posted by jmilk

I just got a nice little box from Microchip Thailand. Three each MCP2515 and MCP2551 in DIP. Getting ready for vacation, so I don't know how much time I'll have 'till October, but I'll try to get a couple of my RBBBs to talk to each other over CAN on protoboards this week. Wheee!

Cool, hope it works out well
According to Yoshi, there's a lot to work on as far as getting the protocol working with a car though. It does seem a little heavier of a protocol than, say, ISO.

[Magister]

I made a little interface (see http://opengauge.org/~obduino/diagram/CANduino.gif ) and plugged it on my Arduino, it works

I modified the code to work with the ELM327, init has some problems it seems, but as I don't check error, it went through...

I can see the RPM on my display, pretty cool, but *argh* VSS is not supported by my ECU it seems?!!??! so I can not display speed or calculate consumption. MAF is working at least!

Time to investigate... I should be able to upload a fake application on the duino and with a null cable talk directly from a laptop to the ELM327 as it will go through the MAX232 of the duino board, and I could test some dos/windows application.