Phidgets Forums

Hello
I need to measure the amount of fuel used in a race car. I already have the flow meter. This has a reed switch output for a given flow, which is 200 pulses = 1 litre.

I have these requirements:
- Measure up to 100 litres, so need to count 20,000 pulses.
- Display the current consumption total on an in car display to 1 decimal place.
- When refuelling, I need to be able to reset the total by a push button held down for approx. 3 seconds.
- The count needs to be non-volatile if power is lost.
- If possible, upload the total to an FTP site / HTTP POST site with a configurable frequency (approx. 1-10 times per minute)

I am looking to use the VINT hub as a device for input/output. I’m not sure what to do regarding the device to use?

Would I be best to use an Android device with an on-the-go cable or go Raspberry Pi or some other route?

I like the idea of Android as this has built in screen / power so this takes care of display/battery backup.

Does anyone have any experience/pointers?

Thanks in advance!

Your system could look like this:

- Graphic LCD Phidget (or LED Phidget with 7-segment LEDs) to display fuel consumption
- Versatile Input Phidget to read flow meter using FrequencyCounter mode
- A VINT Hub to control the above boards
- Any pushbutton, connected to one of the ports on the VINT Hub using DigitalInput mode

You could use a Raspberry Pi (I recommend using a powered USB hub in this case, since the USB ports on the Pi often do not have enough power), or you could use a Phidget SBC4. If you use the SBC4, you don't need to buy the VINT Hub mentioned earlier because the SBC4 already has six VINT ports built-in.

As for your other requirements (non-volatility and data upload), they will be fulfilled by the program you write. (For example, your program could periodically write flow data to a file so that it could pick up from where it left off in case of a power outage).