Carbibbles
New Member
Hello all, I have a basic understanding of electronics. I have built circuits and designed a couple simple schematics for myself in the past. But I have come across something that is a little above my knowledge and I was wondering if I could get some help with it.
I am reprogramming a Subaru ECU to take input from an ethanol content sensor and use it to adjust fuel trims and ignition timing. I have an available port on the ECU that takes a 0v-5v input, but the problem is the ethanol sensor outputs in square wave frequency. The output of the sensor is 50hertz for 0% ethanol and 150hertz for 100% ethanol. So I need to build a small circuit to convert this into 0v-5v so that the ECU can read it. I did some searching and found a handful of people talking about various schematics but I couldn't find anything close enough to my exact situation that I could build from or tweak. So I was hoping somebody here might be able to give some insight to a schematic or at least get me pointed in the right direction.
Here is a link to info about the sensor (about halfway down the page under "Fuel Composition Sensor Description" https://www.megamanual.com/flexfuel.htm
Thank you
Jason
I am reprogramming a Subaru ECU to take input from an ethanol content sensor and use it to adjust fuel trims and ignition timing. I have an available port on the ECU that takes a 0v-5v input, but the problem is the ethanol sensor outputs in square wave frequency. The output of the sensor is 50hertz for 0% ethanol and 150hertz for 100% ethanol. So I need to build a small circuit to convert this into 0v-5v so that the ECU can read it. I did some searching and found a handful of people talking about various schematics but I couldn't find anything close enough to my exact situation that I could build from or tweak. So I was hoping somebody here might be able to give some insight to a schematic or at least get me pointed in the right direction.
Here is a link to info about the sensor (about halfway down the page under "Fuel Composition Sensor Description" https://www.megamanual.com/flexfuel.htm
Thank you
Jason
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