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16  Forum 2005-2010 (read only) / Exhibition / Re: HABS (Halfluck Automated Brewing System) on: August 02, 2010, 01:11:27 am
Hi,

can you tell us more about the pumps ?
there are other project that could benefit for good pumps

and are you driving the pump and stirrer motor with the relay or have you implemented variable speed controller ?

thanks
-shodan
17  Forum 2005-2010 (read only) / Exhibition / Re: Electronic Boost Controller forTurboChargedEngine on: July 31, 2010, 11:33:44 pm
thank you*


*from the person reading this in a couple month looking to make it's own boost controller

smiley-wink
18  Forum 2005-2010 (read only) / Exhibition / Re: Electronic Boost Controller forTurboChargedEngine on: July 30, 2010, 03:35:16 am
I hope you would share it !

many people only want to share it when it's "nice enough to be seen by others" but then never quite reach that point and the precious information never gets out

I am going to make one of these in the not so distant future  (as part of a larger engine management system) and this would help me re-invent the wheel a little less !

are you using a solenoid valve that is just between the intake manifold vacuum and the wastegate pneumatic actuators ?
or do you use a solenoid for direct actuation of the wastegate ?

my friend's commercially made electronic boost controller controls a 3-port solenoid valve (not sure what is the internal configuration yet) so it's just restricting vacuum electrically, and I guess there is a    "vacuum tank" on the 3rd port

also I think everyone doing car-related arduino hacking should get together to coordinate the efforts because I think there is a lot of "re-inventing the wheel" going on between projects
19  Forum 2005-2010 (read only) / Exhibition / Re: Electronic Boost Controller forTurboChargedEngine on: July 25, 2010, 10:51:04 pm
how would you read it ?

I suppose a halls effect sensor would be too slow ?
100krpm is 1.7 kHz  also an halls effect sensor would disturb the airflow ?
20  Forum 2005-2010 (read only) / Exhibition / Re: Electronic Boost Controller forTurboChargedEngine on: July 25, 2010, 01:09:46 am
I think the name "multidisplay" is a bit of an understatement

at some point you will probably drive the injectors, and have a 434mhz RF input, remote starting, a gps & gprs for anti-theft and recovery, RFID key fob to replace the ignition key, and ion sensing for knock prevention !! and probably other things smiley-wink


btw instead of using an solenoid valve to control vacuum from the intake manifold to the wastegate pneumatic actuators, why not use a linear actuator and directly actuate the wastegates ?
also is there a way to sense turbo shaft speed ? (halls effect sensor near the impeller maybe ?)
21  Forum 2005-2010 (read only) / Exhibition / Re: Electronic Boost Controller forTurboChargedEngine on: July 24, 2010, 05:04:29 am
did anyone ever came out of this ?
my friend just bought a 500$ electronic boost controller for his RB26 and I think it can be done with a 12$ arduino and a 5$ solenoid air valve !
22  Forum 2005-2010 (read only) / Exhibition / Re: FARGDUINO / Fuel Air Ratio Gauge Arduino. on: August 06, 2010, 01:57:46 am
using a flashlight housing as a gauge, that is an awesome idea I love it !!!
23  Forum 2005-2010 (read only) / Exhibition / Re: FARGDUINO / Fuel Air Ratio Gauge Arduino. on: August 02, 2010, 12:39:07 am
if you want to measure exhaust O² proportion you will need a wideband o² sensor because the other types can only tell you if it is rich or lean but not by how much, their response is very non-linear

but to read a wideband o² sensor accurately is complicated (less so if you give up some accuracy)

IMHO, the best article on the subject is this page
http://www.megamanual.com/PWC/index.htm

written by the guys behind the megasquirt, it's not a finished product but the theory of operation is very clearly explained

the guy says it can't be done with a 8-bit mcu and that you need a hybrid mcu/dsp chip like the Motorola 56F8323 but "cheap" off the shelf controller use 8-bit AVR like us so it can be done (the Innovate Motorsport LC-1 uses a 8-bit mcu, can anyone confirm ?)

a good Bosch LSU 4.2 wideband O² sensor costs about 39$  btw

be sure to read

"How the Wide Band Sensor Works"
http://www.megamanual.com/PWC/LSU4.htm
"Precision Wideband Controller Hardware"
http://www.megamanual.com/PWC/PWC.htm


it's a LOT of material and you can probably skip the math part until you are actually writing software

it will probably need a couple read for all of that to sink in but after that you will understand wideband O² sensors
and I think there is a big need to an accurate opensource wideband o² sensor controller

hope this helps (and not discourage you smiley-wink )
24  Forum 2005-2010 (read only) / Exhibition / Re: Multidisplay, a Open Source inCar Display, Logger on: July 24, 2010, 01:49:29 am
wow there is a lot of yummy data in that plot !!!

nice to see the output of the o² sensor is basically digital

that the throttle is really not spending any time in between closed and full open
you can even tell how good you shift was if there was a wheel speed sensor and knowing the transmission gear ratios
also you can tell how much boost lags behind rpm and throttle and how sharp your BOV response is

also it looks like your EGT is measuring more the exhaust pipe temperature than the exhaust gas temperature because that curve shows a lot of inertia !

I'd love to see a 20 minute drive downtown & highway video with this data superimposed, we could learn a lot about the car performance and driver's hability

hey also I think this project could be a very good general purpose data acquisition platform

something like this discussion was talking about http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1196965541/87#87

can you tell me more about this bosch ECU ? is it an OEM ECU made by bosch ? or a special aftermarket one made by bosch ?
do you have information about injector and spark timing and duration that could be superimposed on the data you just posted ?

25  Forum 2005-2010 (read only) / Exhibition / Re: Multidisplay, a Open Source inCar Display, Logger on: July 21, 2010, 02:09:05 am
Hi,
but how are you reading the narrow band sensors ?
since they are very non-linear if you just remap the 0 to 1 volt on a linear scale and average out the measurements I don't think this give you any idea if it's really running lean, rich or stoich

are you looking for reversal between lean and rich reading at a maximum interval to declare the engine running stoich ? (and if no reversal happen after the set amount of time then it is rich or lean)

do you have real world sensor output on a graph ? that would be interesting !

for the calibration, yes I have access to the gases because I have a very well furnished hacker space =)

I read about the LC-1 and the "wbo2" controller and I do not believe they are accurate, sure they show numbers and come in a pretty case but I just don't think they are accurate enough for an engine management sensors, if you read the extremely interesting document about the "Precision Wideband Controller"
http://www.megamanual.com/PWC/index.htm
they say that you have to very accurately maintain and measure the temperature of the sensor using the heater, and also output with the sensor signal a "margin of error" signal for when the temperature goes to uncorrectable values (ice water splashing on the exhaust, or engine running more than 800 C )

also you have to apply current to the oxygen pump so the cell stays at 0.450V and it is the current value required to do that, that you read to get the air/fuel ration, and this current change for the same AFR if the cell is at a different temperature

I just don't think the LC-1 or the WBO2 controllers have all that working

you can get just the LC-1 controller with no display and no sensor that would be useful and almost cost effective but it's not good enough (or at least innovate motorsports isn't proving it's doing what it has to do to get accurate readings)
so we have to start over !

for starters, the LC-1 that my friend bought from IM themselves, doesn't come calibrated, they have a crude auto calibration, but I don't believe it works for better than 15% accuracy

good enough for the bling that an AFR gauge is but not for any kind of serious engine management

also I didn't say the Bosch 4.2 is a bad sensor but (and I can't find out where, right now) I read somewhere that the 4.9 was more tolerant of having high pressure exhaust gas blown on it, for example on the RB26 the oxygen sensor plug is right after the turbo outlet and right at the apex of a 90 degree turn in the pipe so the full blow of the exhaust is bearing down on the sensor , surely that would need a LSU4.9  to be accurate if what I read is true
26  Forum 2005-2010 (read only) / Exhibition / Re: Multidisplay, a Open Source inCar Display, Logger on: July 19, 2010, 04:38:32 am
how do you know that your lambda measurement is accurate ?
first I though narrow band oxygen sensors were very non-linear
basically you can only tell if it is running rich or lean and the computer uses this to adjust the injection time so that the sensor will oscillate between rich and lean constantly

so I guess to know if your engine is healthy you wouldn't just display the actual value of the sensor nor an averaged value
but you would display, maybe, how often per unit of time the sensors switched between rich and lean (I would guess the more often the better, and if it stayed at one value for too long that would be a fault condition and if it stayed lean for too long that would be a "master fault" requiring engine shutdown or limp-home mode)

plus there are at least 3 main types of sensors

zirconia narrowband, this is the most common
zirconia wideband, I guess this is what new cars and performance cars have , also what they use in aftermarket A/F gauges

and titania sensors which is rare (but I just happen to find some on a nissan RB26DETT engine, these are coupled with EGT sensors I guess because their response is temperature sensitive)


a good O² sensor controller should support all of these I guess, so that all can benefit without buying new sensors

but maybe people playing with this will like to buy new wideband sensors

a narrowband sensor with no heater costs 10$
http://cgi.ebay.ca/O2-OXYGEN-SENSOR-STD-1WF-SG12-HONDA-CRX-91-84-/200335656679?cmd=ViewItem&pt=Motors_Car_Truck_Parts_Accessories&hash=item2ea4ef86e7

there's another kind that has a uncontrolled heater that is still narrowband but gives accurate measurement faster

you can get a wideband for about 40$
this is a Bosch LSU 4.2
it's a good sensor but it doesn't like high pressures

http://cgi.ebay.ca/Bosch-057-Wideband-Oxygen-Sensor-17014-Innovate-3737-/120585859399?cmd=ViewItem&pt=Motors_Car_Truck_Parts_Accessories&hash=item1c137a3147

a Bosch LSU 4.9 costs about 60$ I'm not sure if it's better a getting high pressure gas blown on it, there's another one called LC-1 that apparently you can put right after the turbo for the best response, I think they cost 140$ I can't find a link right now

there's a company called innovate motorsports and they make overpriced aftermarket automotives gauges and supposedly they use LC-1 sensors

the thing with wideband O² sensors is that to be accurate they have to be temperature controlled so that have a builting heater that you have to control and some sort of temperature, probably a K type thermocouple

to get an accurate reading you either keep the temperature at a stable temperature (I haven't found the celcius value yet) and the reading you get you run through a formula that takes into account the sensor response curve and that gives you the air/fuel ratio, but sometime the heater is not powerful enough to keep the temperature off so you have to compensate for it in the formula, also if the engine is heavily loaded the sensor temperature can go higher than the desired temperature even with the heater completely off. you have to compensate for that too

there is more information on how to make a wideband o² controller
http://www.megamanual.com/PWC/index.htm

but crucial details have probably been left out to impede DIY development of wideband o² controllers so information from the megasquirt project should be considered suspect until proven otherwise (megasquirt is a partially open ECU system that is getting more secretive as the community is no longer needed by the development team except for marketing purposes)

but still, there is a lot of good information on the megasquirt forum so that's a good source, just be wary





oh and I thought maybe it would be a good thing to have a break point between the datalogging and sensor interface backend and the display and user interface front end


maybe the backend could be a good start for making a truly open ECU

and a break point like this would allow someone to develop a separate front end , maybe some user want to re-use their cluster gauge, or use stepper motor dial gauges or even 7-segment, or those nice 3" cell phone graphical LCD but don't want to mess with the back end ?

what do you think ? makes sense ?
27  Forum 2005-2010 (read only) / Exhibition / Re: hexapod walking robot, delta robot on: July 25, 2010, 01:27:52 am
that is awesome

I wonder how big we can make them with cheap servos
28  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Open Source Data Logger Project Using the Arduino? on: July 18, 2010, 06:35:46 pm
instead of trying to make a "one size fits unknown" datalogger
I think the first thing would be to list all the sensor types likely to be hooked to this datalogger and from that determine what input conditionning will be required at minimum for more kinds of sensors
so at least it's known which input conditionning facilities should be on a standard datalogger and which type can be left off a add-on adapter board

also someone should do an inventory of all open source datalogger project that can be found and enumarate their features and scan them for "good ideas" to incorporate in this design


datalogger are often needed but they come in so many brands and model and industries because the people who measure temperatures over weeks don't know about the people who measure fuel/oxygen ratios during minutes and they don't know about the people who measure viscosity over months but they can all benefits from a single common datalogging core with just add-on for their specific application

datalogging for most is an expensive and R&D intensive affair that has no re-use value that's why people pay 500/1000/2000$ for a datalogger that have specs all over the place and there's a reason for that , there's big money to be made in keeping each project unique and personnalised and impossible to compare/shop around for

and lastly the most important of all, this project needs a good name that clearly indicate what it does to people who need it yet don't know what it is yet and it should be easy to find so that the next time someone needs to log the humidity of their bathroom over the next year they don't re-invent the wheel again !!!
29  Forum 2005-2010 (read only) / Bar Sport / Re: Are they cooking something new for us? on: September 10, 2010, 02:48:07 am
it's an xmega arduino with dma and external DRAM ! wooo !
30  Forum 2005-2010 (read only) / Bar Sport / designing a MC34063 SMPS with eevblog's dave on: September 09, 2010, 09:49:30 pm
Hi,

I just saw this awesome video at eevblog

http://www.eevblog.com/2010/09/10/eevblog-110-lets-design-a-dc-to-dc-switchmode-converter/

it clearly details how to make a very flexible (3V to 40V 1.5 amps inverting 60 to 70% efficient) power supply using a generic MC34063 chip
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