• Link 10K Resistor between +5V & D10 pins.
• Attach +12v source to VIN pin & Flex fuel Sensor.
• Attach ground to GND Pin & Fled fuel Sensor.
• Attach Flex Fuel vOut (signal wire) to D10 pin.

• Link 10K Resistor between +5V & D10 pins.
• Attach +12v source to VIN pin & Flex fuel Sensor.
• Attach ground to GND Pin & Fled fuel Sensor.
• Attach Flex Fuel vOut (signal wire) to D10 pin.
• Attach OLED GND pin to Arduino GND pin.
• Attach OLED VCC pin to Arduino +5V pin.
• Attach OLED SCL pin to Arduino A5 pin.
• Attach OLED SDA pin to Arduino A4 pin.

DAC or PWM Analog Out

There are two methods of sending analog flex-fuel signal to a device that requires it:
D9 pin will output a 0-5V (or 0.5-4.5V) PWM voltage, which is a pulsed signal.
Leverage a DAC chipset to send a 0-5V(or 0.5-4.5V) smooth signal.
You may use one or both.
See DAC FAQ for detailed information.

Additional Input

If you’d like to monitor a 0-5volt sensor on your vehicle (for example a MAP), you may tap it into the A1 pin and it’ll show as a bar graph/triangle slider on the OLED (bar graph only on Andriod app). By default the code has this feature disabled, so you’ll have to set the featureAnalogInA1 to 1 and flash your board. DO NOT ATTACH A1 TO ANYTHING GREATER THAN 5 VOLTS!!! The Arduino can only handle 5 volts max on all D & A pins. If you’d like to monitor a resistive circuit (like an IAT or ECT sensor), read the Unity Gain Buffer/Voltage Follower section.

Unity Gain Buffer / Voltage Follower

If you’d like to monitor a resistive type of sensor (i.e. IAT or ECT), you need to set up a voltage follower circuit. The reason is if you try to measure the circuit directly, by the act of measuring it via Arduino will alter the sensor values. A true rail-to-rail in/out Amp is needed for the full range, such as the LMV932MA chip. It’s recommended any dual amp style chips to fully close the unused amp, so in this case we are telling both to do the same otherwise “wonky” things may happen.

Chip Schematic

• Link pins 1&2 on LMV932.
• Link pins 3&5 on LMV932.
• Link pint 6&7 on LMV932.
• Attach LMV932 pin 8 to Arduino +5V pin.
• Attach LMV932 pin 4 to Arduino GND pin.
• Attach LMV932 pin 1 to Arduino A1 pin.
• Attach IAT/ECT sensor to LMV932 Pin 3.

About the code

If you choose to flash your own custom code through Arduino IDE, or create.arduino.cc, at the top of the main program code you’ll see a bunch of flags, change them as you see fit. For example if you intend to use the unit with a DAC chipset connected to Cobb AP3 using a 0.5-4.5v range, you should make sure the first and third flags are set to 1.

Note: If you enable featureAnalogInA1 without anything attached to the A1 input pin, the bottom triangle gauge/bar graph will be bouncy and could be annoying. If you want to keep it enabled for future use, to prevent the bouncy, temporarily tie the A1 pin to ground.

Another note: If you enable featureDAC without the MCP4725 chipset, it doesn’t have any adverse effects; same with enabling featurePWMout without anything attached.

///////// Features can be enabled or disabled below ///////
int featureDAC = 1; //DAC analog output (MCP4725 required) default=1 (enabled)
int featurePWMout = 1; //PWM Analog output (pin D9) default=1 (enabled)
int voltOUTRange = 0; //PWM&DAC Output Range (0=0-5v , 1=0.5-4.5v) default=0 (0-5v) Setting to 1 will output 0.5v-4.5v and also enable Cobb error conditions
int featureAnalogInA1 = 0; //0-5v Analog Input(Pin A1) for bar graph default=0 (disabled) (setting this to zero essentially