Trip / MPG Computer

[wmax351]

My other project for my K75 is a trip computer. I will be setting up a MPGuino to work on my bike, which will display the mpg, fuel consumption, etc. I may modify the code, and tap into the temperature sensor as well.

http://ecomodder.com/wiki/index.php/MPGuino


Its pretty much a modern version of Fuel+. Will be a bit bigger, though, and have a nice LCD with a red backlight.


I need to figure out what the output from the speed sensor is. Is it a VR sensor?  I basically need a square wave at logic or higher level voltages.

[frankenduck]

It's magnetic and sinusoidal, not square.

[wmax351]

It's magnetic and sinusoidal, not square.

I figured. Do you know if it is a VR type sensor?

I'll probably set up a conditioner circuit.

[frankenduck]

Don't know the details of it.  I just know that it's an analog magnetic device so it's not going to put out a square wave like a digital device would.

The best way to tell what the output looks like would be to hook it up to an oscilloscope.

[pallum]

I also remember seeing someone that mentioned the output from the sensor is in the microamp range, which might make it difficult to pick up without a bit more circuitry, which might also interfere with it's normal operation... If the output really is that low (which wouldn't surprise me)

[wmax351]

Yeah. Looks like a VR device. I will use a LM1815 conditioner chip, which will give a nice square output.

[DRxBMW]

My other project for my K75 is a trip computer. I will be setting up a MPGuino to work on my bike, which will display the mpg, fuel consumption, etc. I may modify the code, and tap into the temperature sensor as well.

http://ecomodder.com/wiki/index.php/MPGuino


Its pretty much a modern version of Fuel+. Will be a bit bigger, though, and have a nice LCD with a red backlight.


I need to figure out what the output from the speed sensor is. Is it a VR sensor?  I basically need a square wave at logic or higher level voltages.

If your home brewed fuel plus + computer reaches fruition, I would be VERY interested in one for my whip.

Years ago, I ran a fuel plus on my K 100 RS. Still pissed, I let it go with the bike when I sold her off.

Hooked up with a guy at a petrol stop that fabricated his own computer last summer, KTM application. 

Below is a copy and paste of an article published in the October 2008 issue of MCN on the Fuel Plus 4.0. This gadget is currently not available. Plus this webite has additional info. http://www.bmwra.org/otl/fuelplus/

ARTICLE:

Product Report

When I was actively competing in endurance challenges, I had an array of devices that were constantly feeding me information, including two GPS devices. One was ded­icated to just displaying data like the num­ber of miles ridden, trip duration and the all-important average speed. The other was primarily devoted to routing me to my next checkpoint, but it also had addi­tional features like instant XM Traffic and Weather capabilities. Moreover, I used a CB radio, countdown timer, voltmeter and the bike's onboard computer to keep me alert and informed – I am of the opinion that you can never have too much infor­mation. And if the Fuel Plus 4.0 Motor­cycle Trip Computer had been available, I would have installed one of those too.

The Fuel Plus was developed by David Weiszbrod and introduced in 1992 for BMW K-models. In addition to having a 12-hour clock, it also moni­tored fuel consumption (miles per gal­lon), miles from last fill-up, average speed, fuel remaining to empty, as well as a number of other related functions.

I ended up installing one of the original units on my 1997 K 1100LT and it proved to be extremely accurate and reliable dur­ing the approximately 20,000 miles I used it. So when I heard that Weiszbrod had developed a new model, I decided to order one for my 1995 K75 "Standard."

Unlike the first-generation Fuel Plus which replaced the dash-mounted clock – a process that made more than one owner very nervous since the instrument pod had to be removed and disassembled – the Fuel Plus 4.0 is a stand-alone unit.

Made from polycarbonate and mounted near the left grip for easy access, it has a sleek and clean appearance with no exter­nal buttons. Scrolling through the func­tions is easily accomplished by means of two hidden touch pads on either side of the display. It is also completely weather­proof and even has an internal heater to reduce fogging in colder weather, can be used with winter gloves, and is backlit for easy viewing at night.

While the directions appeared to be straightforward, I wanted to ensure that I eliminated any potential errors during testing as my expertise in soldering and installing electrical components is lim­ited. So I enlisted the help of respected motorcycle technician Roger Sinclair to make all the necessary connections. He had it mounted in about two hours and after performing a couple of tests, pro­nounced it ready to go.

Programmed into the new Fuel Plus computer are many functions found on the original including a clock (12- or 24-­hour), fuel gauge (monitored as a percent­age of fuel remaining), odometer (miles or kilometers), fuel economy, daily stats (miles ridden, running time, and average speed), voltmeter, several waypoint related functions, and miles/kilometers remaining in the tank. It also has several new features like ambient and engine block temperature (Fahrenheit or Celsius), and the ability to set alarms to monitor the battery, charging system and temperature.

The Fuel Plus 4.0 really is a worthy successor to the original in every respect and proved to be just as accurate as its predecessor. When I measured the bike's engine block temperature with an infrared heat gun thermometer, for exam­ple, and compared this reading with the Fuel Plus, it was within one degree. I also found that the ambient temperature reading was also within a degree or two of the known outside temperature and the average speed matched what my GPS indicated.

But the real purpose for the Fuel Plus is to accurately monitor fuel consumption. In this regard, it does it better than any pro­duction motorcycle computer I've ever used. Unlike onboard motorcycle comput­ers that simply rely on the float level, the Fuel Plus measures the distance traveled and compares this number with the fuel remaining in the tank. According to Weiszbrod, his computer measures fuel consumed (by the drop) as it passes through the fuel injectors, while taking into account things like changes in wind load and speed in order to provide precise data. And if this weren't enough, it can even be tailored to meet the needs of the rider or motorcycle.

Long-distance riders who use an aux­iliary fuel cell can now calibrate the Fuel Plus to monitor the gas in both tanks so they'll always know percentage of fuel used and how many miles they have until empty.

If there is one drawback to the Fuel Plus, it's ease of use. The unit is packed with so many features that scrolling to a particular setting can be tedious, at least initially. If the clock is used as the default function, for example, it takes seven steps to get to the odometer. This also means that you can't back up one function-you have to go all the way around. Unfortu­nately, this is the price you must pay when using a compact computer with only two buttons.

But once you understand how the Fuel Plus works, this becomes a minor incon­venience at worst. And while the LCD characters in the display might appear to be somewhat thin and archaic, I never had a problem reading the information in direct sunlight or at night.

I am an advocate of supporting small businesses, especially motorcycle entre­preneurs, that offer well-designed and use­ful products and provide good customer service. In this regard, David Weiszbrod more than exceeds these criteria.

Priced at $337, he has designed an attractive, functional and accurate product at a fair price. The Fuel Plus 4.0 is avail­able for fuel injected BMW K75, K100, K1100 models, Oilheads and K1200s, FL Harley-Davidsons and GL1800 Gold Wings. Weiszbrod is also considering adding KTM 990s and Yamaha FJR 1300s to this list if there's an interest.

[Scott_]

I have the 4.0 version on my '95LT, I like it.
It is a shame that Dave isn't making them anymore. He even let his web name expire.
I think I may still have his e-mail/phone # available if anyone is interested in trying to contact him.

[frankenduck]

Another possibility for speedo signal is the blue/green wire from the speedo tp the flasher relay that does the turn signal auto cancel after 100m or so.  Although I'm not sure if the circuitry for that is in the speedo and it sends one pulse or if it forwards the speedo pulse to the flasher relay and the circuitry is in the flasher relay.

[wmax351]

Another possibility for speedo signal is the blue/green wire from the speedo tp the flasher relay that does the turn signal auto cancel after 100m or so.  Although I'm not sure if the circuitry for that is in the speedo and it sends one pulse or if it forwards the speedo pulse to the flasher relay and the circuitry is in the flasher relay.

I believe it is a single pulse.


I would be willing to make some of these. If I find some interest, I can do a PCB order, and make a bunch of them. I can also just etch my own pcbs, which is also easier the more you do.



I can make one specific for the K Bikes pretty readily.

[wmax351]

if its baddass cool and priced right i will take 4 of them...

j o

Good to hear. I will see what the total comes out to for each one. The parts will work out to probably 20-25 dollars each, though not completely sure, especially in quantity.

Time is the big issue. If I get enough interest, I will do a batchPCB order, which will greatly reduce the time required to make each one.

[motodude]

if its baddass cool and priced right i will take 4 of them...

j o

Yes, depending on price and "form factor" I might be interested in two.  I'm just not badass cool enough to require badass cool-ness.

Tom

[wmax351]

A lot of these variables are dependent on price point. More $ for my labor=smaller size devices, and nicer cases. I can do SMD soldering, but it is a bit trickier. I'll start out with my through hole, prototyped one, and see how it works.

What is the best form factor for these? I can do a single package, with processor and LCD in one. I can also do a separate "Brain" and display.

The Display unit is 80mm x 36mm. The buttons will be on the side, and probably add about 10mm. so we're looking at a 90mm x 40mm box. Probably will use black ABS project enclosures.

The feature set on these is pretty significant, and have room for expansion. I may add temperature reading capabilities to mine. This system allows for total fuel consumed to be displayed (think ridiculously accurate fuel gauge).

http://www.mouser.com/Search/ProductDetail.aspx?R=NHD-0216K1Z-FSR-GBW-Lvirtualkey66010000virtualkey763-0216K1Z-FSR-GBW

These are the LCD's I'm using. Any other 16x2 display with the same interface chip would be usable. There are a variety of colors available.

A simpler one could be made smaller, that only does instant or distance mpg. I could use a couple of 7-segment LED displays, to display a simple "Miles/Fuel used" calculation, with a hard-coded pulse per mile and fuel injector rating values. It would not be adjustable without a programmer. For K bikes, the tire sizes change somewhat, with a fairly significant difference. IE: 2.03-2.14 meter circumference. I could add an adjustment potentiometer, but would only be a trim/correction factor, and not a true adjustment.

The disadvantage of this is I would have to develop my own code.


What would people be willing to spend on one of these? I know the fuel-plus was a few hundred dollars, numerous years ago.

Here is a survey I put together. If you are interested,
https://docs.google.com/spreadsheet/viewform?formkey=dElJOHotbTFpUTVtSm92aGRqUWZ0aUE6MQ


This could work out to be a great summer job/project if there is enough interest. 

[frankenduck]

Ambient temp is a good feature IMO.  I'd go with an external temp sensor that you can hide from the sun so it doesn't give falsely high readings.  I've got a VDO ambient temp gauge on my red bike. Once I calibrated it with an in-line variable resistor it's' pretty accurate with the sensor hidden up in the fairing, away from the sun and the engine heat.

[wmax351]

Ambient temp is a good feature IMO.  I'd go with an external temp sensor that you can hide from the sun so it doesn't give falsely high readings.  I've got a VDO ambient temp gauge on my red bike. Once I calibrated it with an in-line variable resistor it's' pretty accurate with the sensor hidden up in the fairing, away from the sun and the engine heat.

I was thinking engine temp, but ambient is also useful. Just a cheap, linear temperature sensor, with a wire to wherever one wants to mount it.

[mystic red]

if its baddass cool and priced right i will take 4 of them...

j o

+1 but only one baddass unit for this bricker!
You need to figure out materials cost and $$ for your time and then hit us with a price. Just me, but I would have had me a Fuel Plus but $400 made me cough up a lung when the odometer gets me in the ball park.

[Duc750]

Sounds like a fun project.

I might well be in for one - one thought though - could you make it so it fits the "map" light on the LT fairing ? - add a couple of LEDS into the bottom of it to replace the map light and it would slot in a treat.

[wmax351]

Sounds like a fun project.

I might well be in for one - one thought though - could you make it so it fits the "map" light on the LT fairing ? - add a couple of LEDS into the bottom of it to replace the map light and it would slot in a treat.

Should be doable. What are the dimensions for that?

[wmax351]

if its baddass cool and priced right i will take 4 of them...

j o

+1 but only one baddass unit for this bricker!
You need to figure out materials cost and $$ for your time and then hit us with a price. Just me, but I would have had me a Fuel Plus but $400 made me cough up a lung when the odometer gets me in the ball park.

I should have a prototype in the next few weeks. Once I have that done, I can make a circuit board and get some quotes on components.

$400 seems a bit steep to me as well. I can assure you it will be less. I am aiming to have a ~50 dollar kit, and a $100-150 assembled, plug and play version.

The one feature that will be very helpful is the instant mpg. It helps you improve your mileage a ton. You start to learn what the engine and bike likes. I have that on my car ('86 BMW 325es) and it lets me average ~28-30 mpg on the freeway.

[mystic red]

That sounds cool! If it could replace the useless map lite in the fairing it would be semi-orgasmic.

[Duc750]

 :giggles Will it measure in proper gallons or US?

[wmax351]

:giggles Will it measure in proper gallons or US?

It can be set to do either (just figure out how many microseconds/gallon (UK or US) the injectors flow.). There is also a metric version of the code. I believe that does L/100km.

Each injector flows 161 cc/minute at 3 bar, and 146.87 cc/minute at the 2.5 bar our fuel system runs at.

http://www.wolframalpha.com/input/?i=3*146.87+cc%2Fminute+in+us+per+gallon

[WayneDW]

:giggles Will it measure in proper gallons or US?

It can be set to do either (just figure out how many microseconds/gallon (UK or US) the injectors flow.). There is also a metric version of the code. I believe that does L/100km.

Each injector flows 161 cc/minute at 3 bar, and 146.87 cc/minute at the 2.5 bar our fuel system runs at.

http://www.wolframalpha.com/input/?i=3*146.87+cc%2Fminute+in+us+per+gallon

wmax, if you are trying to impress me it is working.   Keep up the good work.

[thebob]

Makes sense to me if you know the flow rate then you just need to time how long the injectors are open per Km. That will be the signal from the Jetronic.

[Duc750]

Now if it will work of both jetronic and motronic its useable for all K and a lot or oilheads too, if that's the case I may be in for two or 3
As far as case material goes have you thought of cnc machined? Its surprisingly cheap for small batches. I will measure the map light this week and have mad a note to measure the depth available when I do the next service in a couple of weeks