E85 Gauge w/ output for under $100
#166
EvoM Community Team Leader
anyone try a low pass filter on the input?
#168
EvoM Guru
iTrader: (2)
Milled out a bracket and finished wiring everything yesterday. Got it all running today. Everything is wired so that it is completely plug and play, no splicing into factory harnesses and is key hot so no switches needed to turn the system on or off. The bracket mounts on the back of the intake manifold using existing holes and can use the factory return line, also gets rid of the return hard line that runs over the top of the fuel rail, just had to get some hose to connect the sensor to the FPR. Now the only thing left to do is figure out why the temp is displaying wrong.
Would anyone be interest in a bracket if I had a small batch made?
Would anyone be interest in a bracket if I had a small batch made?
#175
Does your ethanol content bounce all over the place? Mine will go from 6% to 99%. I checked the output side with a muiltimeter and the wild values are being sent to the ecu. This isn't good for those of us who are trying to go flex fuel.
#176
EvoM Community Team Leader
try buying a quality DC-DC power supply for the arduino and see if that helps clean up the input power. Automotive electrical is crazy noisy with massive transients that the arduino is simply not designed to handle. A good power supply should clean that up.
#177
What is also weird, is that I bench tested the unit and it worked fine aside of the temperature value.
#178
EvoM Community Team Leader
The gauge was designed to work in an automotive environment, it likely has internal circuitry to deal with the problems i was talking about.
#179
EvoM Guru
iTrader: (2)
I still haven't been able to get the temp or ethanol content to work correctly. My ethanol content continues to bounce all over the place. I moved the ground to a closer location and still have the ethanol content reading crazy. I have checked the input side of the arduino and the it is getting a consistent input. It seems that this is an issue within the arduino.
Does your ethanol content bounce all over the place? Mine will go from 6% to 99%. I checked the output side with a muiltimeter and the wild values are being sent to the ecu. This isn't good for those of us who are trying to go flex fuel.
Does your ethanol content bounce all over the place? Mine will go from 6% to 99%. I checked the output side with a muiltimeter and the wild values are being sent to the ecu. This isn't good for those of us who are trying to go flex fuel.
I don't have mine hooked into the ECU for flex fuel as I'd rather have manual control over map switching. Not sure if that would cause any issues. Both my sensor and ardiuno are powered off an add a circuit on the interior fuse box. They're also both grounded in the driver's footwell area behind the fuse box.
I don't have any experience dealing with noise in electrical circuits although I have built shielded wire circuits, I'm not sure it'd be necessary for something like this. Another thing to consider is that my car has next to no electronics in it except for what is required to make it run and some lights so your issue could be from something that's no longer in my car.
#180
Don't have an EVO, but I used this to build my own little gauge for my truck so thanks to the OP for the information.
I did a little bit of testing and found the same problem with the temperature. So I read some more about the sensor and how it outputs the temperature reading and looked at the code and didn't think the code made any sense for what I found.
So I coded up my own way to get the temperature and it seems to be correlating correctly with the coolant temp and intake air temp of my truck while in the garage.
Here is just the portion of the code that gets the temperature:
I did a little bit of testing and found the same problem with the temperature. So I read some more about the sensor and how it outputs the temperature reading and looked at the code and didn't think the code made any sense for what I found.
So I coded up my own way to get the temperature and it seems to be correlating correctly with the coolant temp and intake air temp of my truck while in the garage.
Here is just the portion of the code that gets the temperature:
Code:
void getfueltemp(int inpPin) { //read fuel temp tempPulse = pulseIn(inpPin, LOW, 25000); // Measure the low pulse time (timeout after 25ms if no pulse is detected) if (tempPulse > 0) { // If we get a pulse then update the temperature measurement lowTime = tempPulse; float celsius = ((41.25 * (float(lowTime) / 1000)) - 81.25); // Calculate temp in celsius from lowTime pulse float fahrenheit = ((celsius * 1.8) + 32); // Convert to fahrenheit temperature = fahrenheit; // Update temperature with specified unit } }
The following 2 users liked this post by bubba2533:
Ayoustin (Dec 28, 2017),
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