I am working on another motorcycle project, adding fuel injection. I searched this section and read a few posts about pressure sensors, but did not find exactly what I want to know.
I am using an Arduino Uno.
Here is my project concept:
I have a fuel pump that draws at most 10A on 12V. Instead of using a mechanical regulator, which adds heat to the fuel and requires a return line, I want to use a pressure sensor in the fuel rail to control the pump, which will also use less power (a factor due to the application having limited amps available). The pressure sensor uses 5V reference voltage, has a range is -14.7 to 60 PSI, and the output is .5 to 4.5V. I want to keep fuel pressure around 40 PSI.
I plan on outputting PWM through a Solid State Relay (SSR) since the motor is too large for the Arduino to control. I estimate a duty cycle of perhaps 50% will be sufficient, thereby saving power.
I have a table and formula to convert the sensor output to/from volts and PSI for any given value. The sensor also measures negative pressure, so .5 volt = -14.7 PSI. Of course, 4.5V= 60 PSI. My fuel rail will never see negative pressure. It seems like it would be best to have the Arduino's resolution only where needed, i.e. 0 to say 45 PSI. Maybe I am over-thinking this.
I have read about analogRead and analogWrite, and my question is what about analogReference? Is it necessary to use this function since my sensor is not 0-5V?
Thank you for any help or advice, I am better with wrenches than volts and amps, but I enjoy learning about how to use the Arduino for projects such as this.