Thread: Flex-fuel sensor output

I'm very interested in your results. Please post them.

are you possibly interested in making up a few sets (inc GM EC sensor) with the code on the board to send to Australia?
The sensors are on the expensive side here for us, and the only other real ECA is the Zeitronix unit and it costs us around $300AUD if not more

I'm asking around if anybody is interested....

@ebinkerd After putting two tanks of E70 thru the system, the LCD shows an ethanol content of 67%, which seems well reasonable.

@342Four If I were to make a plug n play kit, I would only include a pre-soldered Arudino+LCD with code. Sourcing the GM-sensor is easy enough, and you can use whatever sensor you can get your hands on. They all output the same frequencies, some people might be able to source a cheap sensor via a dealership, for others there is always china ebay...

I will continue to improve the code this weekend, the temperature readout is coming along great thanks to D-unit

The GM sensor is easy enough to source yes...unfortunately not so much in Australia...I will get in contact with some dealers here to find a price though. eBay has the 'basic' sensor PNo 13577429 for $100AUD shipped from the US - which is a lot more then you can get them for by the looks of things.
What's your estimated price for a 'plug and play' kit? anything is certainly a lot cheaper then $500AUD for a Zeitronix display kit ECA with sensor

All that somebody would need to supply themselves would be a 5v source, a sensor, a sensor plug and some wiring to connect it all up?

Search for the 13577379 , it's available for 55€ from china with free shipping (that is $76AUD)

-Sensor plug is optional, you can crimp spade connectors or solder wires directly to the sensor if you trust yourself

-5V source can be a cigarette USB adapter" for 1-5$

-Arduino is $5AUD, with a $7AUD LCD

-Capacitor and resistor can be had from local electronicsstore, at around 1-3$ (since you always buy bulk) This goes for wiring aswell, a few $.

Total:
-20€ (28 AUD) = Arduino LCD + 5V supply + Wiring + Cap&Res
-75€(104 AUD) = Arduino LCD + 5V supply + Wiring + Cap&Res + GM Sensor

If no one is up to building them on a large scale I could probably get them done at my shop for a pretty good deal. I already make other automotive type gauges at work for the track guys so it wouldn't be to big of a deal to whip them out.

unfortunately no
that GM sensor is $150AUD shipped from the US on eBay, we have no other source other then the dealer
Thus my interest in a complete kit inc sensor

@Y2KG20 I briefly considered putting together a kit using just the basics. But the cost of everything needed is so cheap. Even with my own circuit printing equipment, these arduinos are still made cheaper than the copper clad board I use. But, if you want to pursue it further, I would like to help in any capacity

I got everything in the car. I have Daniel's code on two different gauges from work. For some reason the temp didn't seem to work right and it was probably because I deleted the HZ out for more display space. I'll work on that later. Also I have Johan's Open ECA with Bluetooth running next to it so we can see how close they are to each other. I had my brother run a scanner on his buddy's truck that has built in flex-fuel tuning and the content between all three match up within 1%-2%. I'll test the voltage output next and see if they line up.

Took a quick video

Good stuff man!

Temperature calculation is still work in progress. Some variables aren't stored accurately enough, and the accuracy is +-15 degrees wrong. I will solve this soon.

Regarding screen space, I had a chat with D-unit, and we came to the conclusion that it would be best to remove the xxxxmV for more space on screen. It doesn't match up with the voltage output anyway, so it's gone in the next revision. The voltage output depends on what RC-filter you are running (4.7kOhm + 10uF recommended), and what PWM output frequency you run (35kHz works alot better than standard 489Hz).

The output voltage isn't perfectly linear, but with the above setup, I get 4.5V @ 75% ethanol (It bottoms out at 80% ethanol, not very common to find so high content anyway)

I just finished school, and will have some spare time to finetune the setup and application.