Very excited to see the progress on the flex fuel sensor. Any recommendations/requirements as to which pin to use? I know it has to be configured as open drain with a pull-up.
Re: E85 / Flex fuel logic
Posted: Wed Jan 13, 2021 4:33 am
by AndreyB
Do we have a sample tune and sample log of the sensor actually working? Do we actually log flex fuel?
Do we have a sample tune and sample log of the sensor actually working? Do we actually log flex fuel?
We log it, the channel is called "flex ethanol %" or something like that. You can watch the impact of target afr changing even as target lambda stays constant.
I tested on the bench with a function generator, but to my knowledge nobody has plugged it in to a real sensor yet.
Very excited to see the progress on the flex fuel sensor. Any recommendations/requirements as to which pin to use? I know it has to be configured as open drain with a pull-up.
On proteus any digital input will work. On MRE, you should be able to use the analog temp inputs or the cam input. Analog volt inputs should work too, but will require an external pullup resistor.
Very excited to see the progress on the flex fuel sensor. Any recommendations/requirements as to which pin to use? I know it has to be configured as open drain with a pull-up.
On proteus any digital input will work. On MRE, you should be able to use the analog temp inputs or the cam input. Analog volt inputs should work too, but will require an external pullup resistor.
I am setting up a Frankenso 0.5.6 board at this time. Anything special about that board?
Question: does any rusEFI user have a real flex sensor on a real rusEFI vehicle already wired into a real rusEFI ECU?
I just wired one in. Proteus .4 and continental sensor. Car is currently apart for clutch/trans swap. I should have it back together later this week. I could do some testing then.
Re: E85 / Flex fuel logic
Posted: Mon Sep 13, 2021 7:10 pm
by YuMe3D
Hi All.
Unfortunately not being a coder (Smacks self in the face )
In regards to the Flex input from the Sensor.
I am sure that most are aware that the Flex Sensors have the ability to measure the Ethanol % AS WELL as the Temperatureof the fuel flowing through it.
The first, as we know is the Ethanol Content/concentration %, is done by measuring the Frequency from the Sensor. Being a Range from 50Hz to 150Hz (equating to 0% to 100%)...
A frequency output of 200Hz dictates a Fault condition (Which is primarily indicating Methanol Contamination/Damage)
Now regarding the Temperature measurement aspects of the Flex Sensor is where it now gets interesting, And please verify/validate the ability for RUSEFI to do the following on the Sensor Reading input lines.
Temperature is read from exactly the same input signal as Ethanol Content % (remember this is a 50Hz to 150Hz frequency signal) output from the sensor via a PWM (Pulse Width Modulation) of the output signal.
With the following Curve characteristics.
So to be able to Read both aspects of the Flex sensor RUSEFI would need to be able to Read the incoming Frequency (which it already is able to do) as well as measure the Pulse Width of the Frequency input..
To the coding Gurus out there... Nudge Nudge Wink Wink...
Question: does any rusEFI user have a real flex sensor on a real rusEFI vehicle already wired into a real rusEFI ECU?
I have one in a vehicle, and could easily connect the signal to RusEFI. Engine is destroyed, but I could still run fuel through the sensor and check it.
Those sensors do they report only ethanol content or is there another data point reported by duty cycle?
As mentioned above, the frequency indicates E content, and the duty cycle indicates fuel temperature. We ignore the temperature right now and only look at the E content, but could add fuel temperature sensing & compensation.
Were you actually changing something to change the E content, or is there a bunch of noise somehow?
As mentioned on slack, not changing fuel at all, just low fuel level and multiple key on/key offs (see battery voltage switching between 5-12v). So it may have seen some air bubbles and voltage swings causing some funkiness. In any case it seems the sensor is reading.
Re: E85 / Flex fuel logic
Posted: Wed Nov 01, 2023 4:32 am
by AndreyB
vodka sensor at least two issues?
Re: E85 / Flex fuel logic
Posted: Wed Nov 01, 2023 5:24 am
by mck1117
Unfortunately it's an ethanol vs. hydrocarbon sensor, not an ethanol vs. water sensor. Water or methanol contamination make it read off scale.
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Still have the second problem