Liquid Flow Sensor and RPI
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Liquid Flow Sensor and RPI

by ebharding on Fri Oct 11, 2013 4:00 pm

I tried following the kegbot lesson, but there was no info on how the flow meter is hooked up to the breadboard. I Guessed based on the photo, but got it wrong.

I already did the thermometer lesson and that worked fine. It was still plugged into the breadboard when I hooked up the flow meter, is that a problem?

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Re: Liquid Flow Sensor and RPI

by adafruit_support_rick on Fri Oct 11, 2013 6:26 pm

You want to use GPIO 22, as indicated on this pinout diagram
http://pi.gadgetoid.com/pinout
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Re: Liquid Flow Sensor and RPI

by ebharding on Sat Oct 12, 2013 1:59 am

Thanks, since I am a total novice on the h/w side, can you recommend a good book or tutorial to get up to speed on the GPIO or a basic electronics primer?

Thanks

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Re: Liquid Flow Sensor and RPI

by adafruit_support_rick on Sat Oct 12, 2013 8:13 am

We vet all the items in our Books section before stocking them, so they're all good. Browse through it and see if something strikes you:
http://www.adafruit.com/category/40
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Re: Liquid Flow Sensor and RPI

by fl0 on Mon Mar 31, 2014 2:13 pm

You want to use GPIO 22, as indicated on this pinout diagram


Is there a reason to use GPIO 22 rather than 17?

I'm using the prototyping plate http://www.adafruit.com/products/801 and confirmed my python code works with a push button, but fails when using the sensor.

Is a voltage divider circuit necessary to bring signal down to 3.3V for RPi?
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Re: Liquid Flow Sensor and RPI

by fl0 on Mon Mar 31, 2014 2:36 pm

The pictures in the article imply the sensor is wired directly, however when I do this, it doesn't detect a state change either. My python code only detects a 1 when wired like this and I believe it's not good for the RPi?

http://learn.adafruit.com/adafruit-keg-bot/prototype-circuit
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Re: Liquid Flow Sensor and RPI

by adafruit_support_rick on Mon Mar 31, 2014 5:50 pm

fl0 wrote:Is there a reason to use GPIO 22 rather than 17?

No reason. It's just the way the code was written
fl0 wrote:The pictures in the article imply the sensor is wired directly, however when I do this, it doesn't detect a state change either. My python code only detects a 1 when wired like this and I believe it's not good for the RPi?

So, you're running the flow meter off 5V, right? Yes, that does seem odd. I guess I'd set up a voltage divider on it.

Even so, it should detect the state change, if you're running it on 5V.
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