Anything not specifically related to the Speeduino hardware. Eg sensors, bluetooth, displays etc
By wassis67
#42259
Hello guys, I'm new here and I need help with the wiring to connect an flex fluel sensor to the V. 0.4.3b board. I did not find anything in the documentation explaining which board specific inputs and pins I should use with the flex fuel sensor.
Thanks for any help.
By stum
#42309
Directly from the Doc's -- Speeduino Manual 04/08/20

---------------------------------------------------------------------------------------------------------------------------------
Wiring
All units are wired identically and have markings on the housing indicating what each pin is for (12v,
ground and signal) Speeduino boards v0.3.5+ and v0.4.3+ have an input location on their proto areas
that the signal wire can be directly connected to. 43

On boards earlier to these, you will need to add a pullup resistor of between 2k and 3.5k Ohm. Recommended value is 3.3k, however any resistor in this range will work. Note that this is a relatively strict
range, more generic values such as 1k or 10k DO NOT WORK with these sensors.
------------------------------------------------------------------------------------------------------------------------------------

So in on pin 14 to IDC connector. Pull up resistor in prototype area (id assume to +5V). And you should be good to go

I have not gone any further my self yet..... another job on the list. good luck
#42399
My card is V. 0.4.3b.
If I got it right I should connect pin 43 of the proto area to pin 14 of the IDC and then connect the signal from the flex sensor to pin 14 (as well as supplying it with 12v), correct?
Doing this, TunerStudio will read the flex sensor automatically and make corrections based on the values ​​in "Fuel Sensor Setings", correct?

The current version of the manual does not inform the proto area pin that receives the signal from the flex sensor, look (page 42):
......................................................................................................................................................................................
Wiring
All units are wired identically and have markings on the housing indicating what each pin is for (12v,
ground and signal) Speeduino boards v0.3.5+ and v0.4.3+ have an input location on their proto areas
that the signal wire can be directly connected to.
.......................................................................................................................................................................................
Thanks for the tips! :)
By stum
#42400
Ive been using the on line PDF.

https://speeduino.com/Speeduino_manual.pdf

Yes pages 42 for flex fuel. And pages 103-105 for V0.4.X boards. These are general purpose, and in your case you are going to use IDC pin 14 --> mega pin 43. You could use a number of others as you can change the configuration. But default is mega pin 43, which is beside pin 14 in prototype area. Hope that has made sense.

And yes you are on to it. but don't forget the pull up resistor.......

Yes sensor will need its own +12V and 0V (ground) supplied to it.

Signal will come back to IDC Pin 14 (default). And out into the prototype are beside that pin. You will need to put a jumper across to where it say 43 (default arduino mega pin) it will also need a pull up resistor to the +5V is my understanding.

Tuner Studio will display the flex fuel information that speedie has read.......

good luck. keep us updated.
#42415
Thanks for the tips, Stum, but now I have more questions... :-)
I'm using this version of the manual you linked at https://speeduino.com/Speeduino_manual.pdf and it doesn't say which pin I should use, how did you find out that it is on pin 43?
Why should I use the pull-up resistor on the V.0.4.3b board?
How to assign another board pin to the flex sensor in TunerStudio or directly in the code?
By stum
#42423
Ok, i'll start with the pull up resistor. I have not done this my self yet. but im assuming the Flex fuel sensor signal is a pull low in the device. and you will need the pull up resistor to get a +5V signal into the Mega pin. And the flex fuel will pull it down to 0V. You need to size the upll up correctly (give or take) so not to over power the flex fuel sensor, or create a voltage divider circuit. and by the looks.

FROM MANUAL:
On boards earlier to these, you will need to add a pullup resistor of between 2k and 3.5k Ohm. Recommended value is 3.3k, however any resistor in this range will work. Note that this is a relatively strict
range, more generic values such as 1k or 10k DO NOT WORK with these sensors.

If you do a google search on "flex fuel arduino" you will see other examples of projects using a flex fuel and arduinos, all using a pull up resistor to 5V. Hope this clarifies this bit.

Ok, Ive just started up Tuner Studio. and you can only Turn it on/off. I thought you could change pin configurations. The pin allocation is in the code........... some time latter......

Bit out of the code where it allocates the V0.4 pin's
----------------------------------------------------------------------------------
case 3:
//Pin mappings as per the v0.4 shield
pinInjector1 = 8; //Output pin injector 1 is on
pinInjector2 = 9; //Output pin injector 2 is on
pinInjector3 = 10; //Output pin injector 3 is on
pinInjector4 = 11; //Output pin injector 4 is on
pinInjector5 = 12; //Output pin injector 5 is on
pinInjector6 = 50; //CAUTION: Uses the same as Coil 4 below.
pinCoil1 = 40; //Pin for coil 1
pinCoil2 = 38; //Pin for coil 2
pinCoil3 = 52; //Pin for coil 3
pinCoil4 = 50; //Pin for coil 4
pinCoil5 = 34; //Pin for coil 5 PLACEHOLDER value for now
pinTrigger = 19; //The CAS pin
pinTrigger2 = 18; //The Cam Sensor pin
pinTPS = A2;//TPS input pin
pinMAP = A3; //MAP sensor pin
pinIAT = A0; //IAT sensor pin
pinCLT = A1; //CLS sensor pin
pinO2 = A8; //O2 Sensor pin
pinBat = A4; //Battery reference voltage pin
pinDisplayReset = 48; // OLED reset pin
pinTachOut = 49; //Tacho output pin (Goes to ULN2803)
pinIdle1 = 5; //Single wire idle control
pinIdle2 = 6; //2 wire idle control
pinBoost = 7; //Boost control
pinVVT_1 = 4; //Default VVT output
pinFuelPump = 45; //Fuel pump output (Goes to ULN2803)
pinStepperDir = 16; //Direction pin for DRV8825 driver
pinStepperStep = 17; //Step pin for DRV8825 driver
pinStepperEnable = 24; //Enable pin for DRV8825
pinFan = 47; //Pin for the fan output (Goes to ULN2803)
pinLaunch = 51; //Can be overwritten below
pinFlex = 2; // Flex sensor (Must be external interrupt enabled)
pinResetControl = 43; //Reset control output
----------------------------------------------------------------------------------------------------------------------------------

To me this looks like the Flex Fuel is on Dightal Pin 2.......

With my multi meter, Mega pin 2 is connected to Speedie board V0.4.4 (the Board I have here) development area -- Labeled "Eth"

Phew...... Hope this shines some more light on it for your.......

Cheers
#42430
Yes Stum, your tips were of great help.

The manual is omitted on several important points like this, so I am checking all inputs and outputs with the board electrical diagram and the multimeter before mounting on the vehicle.
I checked now and the "Eth" hole in the proto area is actually connected to the PWM 2 output of the Mega 2560 board.
As for the pull-up resistor it already exists, it is the R61 of 2.49K and 1% tolerance.
I just hope the Flex Fuel feature works well, since the appropriate sensor costs more than USD 50 here.

My sincere thanks! :D
By stum
#42432
All good.

Yes pin 2. By directional. can be input or output. I think as an input it it has an interrupt for accurate timing. why it is used.

Only $50 US. I wish... Prices range here from $180-$400(nz) plus plug so like $108-$240US off the shelf.........

Yes I failed to see the bit about the boards earlier than V0.4. 3 needing the pull up.

It is another job to do for me, as Im running Pump E85 in my toy, but the % content can vary between 50-85%, depending on season......... Down here in New Zealand. So can make a huge difference on tune.

In my sport there have been a few instances where they seem to think the change in ethonal % has killed a few motors. combination of mixture and knock........

I believe there are a number of speedie installs running flex fuel successfully. So you should be fine.

The biggest thing I have found on E85 is cold starts, but that is well documented in other topics on here.

keep us updated in the rest of your journey......

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