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  • Author Author: dang74
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Blog #10 - The Final Push

dang74

Wow, where did all the time go.  It seemed to evaporate.  I tried to stay disciplined with my time management but sometimes life gets in the way.

 

I woke up on Saturday morning with the realization that a whole lot of work still needed to be done.

 

After my coffee I crouched over my kitchen table to solder the remaining components on the carrier board.

 

image

 

 

The first module installed on the carrier was the PROFET 2+ Shield.

image

 

 

Then I installed the DPS368 Pressure2Go module.  He's a cute little guy... smaller than a stick of gum.

image

 

 

And finally, on top of the stack, we have the XMC4700 Relax Kit board.

Wow, I was so impressed with how everything looked together.

image

 

 

So although I was very pleased with the electronic integration there was some disappointment ahead.

 

I was completely defeated by the plumbing. LOL.

 

This is one area that I totally underestimated.  I had a lot of difficulty sourcing the appropriate adapters and plumbing fixtures so I used rubber tubing to attach the solenoid valve.

Unfortunately the smallest amount of pressure would cause the rubber tubing to fail, in turn sending the solenoid into the puddle that was quickly forming in my garden.

 

Things weren't looking too safe so I had to abandon this goal.  For the sake of posterity I've included an image capturing this failed attempt.

 

Please do not try at home:

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I had greater success with the data logging function.  On Sunday night, I 'left the Relax Kit to its own devices'.

After 3 hours or so I checked to see what data was logged.  The results are shown below:

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So, yeah, its kind of cool that it can run autonomously, record data and make decisions based on that data.

And once I befriend a qualified plumber I have no doubt that it will be able to control a water valve. image

 

For the time being my project sits on my TV stand.  He runs autonomously collecting data.

image

 

 

And he's in good company too, being watched over by two of the best friends I ever had.

 

I want to thank Newark Element14 and Infineon for putting together this design challenge.  It provided a good introduction to technologies I wasn't too familiar with like ARM Cortex M4, the XMC series of microcontrollers and the DAVE IDE.  More importantly though, it provided that rare opportunity in life, where you are challenged and given an opportunity to solve problems in creative ways.  For this I am truly grateful.

  • in reply to ralphjy

    Thanks Ralph,

     

    I think I will try your solenoid.

  • in reply to dang74

    Here is the link to Amazon https://www.amazon.com/gp/product/B00K0TKJCU/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

    I think that you can get it directly from Adafruit but I was in a hurry.

     

    The product description says it works down to 3psi but I never tested pressure - I'm sure I was well over that.  I purchased it 3 years ago and used it during late summer and fall for a sprayer irrigation system for a raised bed.  I haven't used it since because I rearranged the raised bed - so I can't vouch for it's longevity.  It is a reasonably inexpensive valve.

     

    Product Description:

    "Control the flow of fluid using the flow of electrons! This liquid valve would make a great addition to your robotic gardening project. There are two 1/2\" (Nominal NPS) outlets. Normally, the valve is closed. When 12VDC is applied to the two terminals, the valve opens and water can push through. The valve has a gasket arrangement inside, so there is a minimum pressure requirement of 0.02 Mpa (3 PSI). Also, liquid can only flow one direction. We tried this solenoid at various DC voltages and found we could actuate it down at 6VDC (although it was a little slower to open). Here is the current draw table for various voltages. We suggest a TIP120 or N-Channel power FET with a 1N4001 kickback diode to drive this from a microcontroller pin. For a power supply, our 9V 1A or 12V 1A power adapters will do the job. These solenoids are not rated for food safety or use with anything but water. Voltage Current 6V 160 mA 7V 190 mA 8V 220 mA 9V 240 mA 10V 270 mA 11V 300 mA 12V 320 mA."

     

     

    Ralph

  • in reply to ralphjy

    Thanks Ralph,

     

    Would you happen to know the model number for the valve you purchased?  The one I purchased is indeed 0.75".  I've done some further experiments since my blog 10 post and what I have found is that the valve requires considerable water pressure to stay open.  I am interested in sourcing an alternative valve that doesn't require so much pressure.  Do you remember if your valve required crazy amounts of pressure... if not I will purchase it along with the Amazon adapter.

     

    Thanks again for the advice,

     

    Dan

  • I did a similar project a few years ago and used a similar solenoid valve from Adafruit that has 1/2" pipe fittings.  The Sparkfun solenoid says that it is 3/4" but the spec and picture look like it is 1/2".

     

    Here is the adapter that I used to connect the solenoid to the faucet - Gilmour Double Female Brass Swivel Connector Thread Size 1/2" NPT (F) to 3/4" NH (F) 805574-1001,  https://www.amazon.com/gp/product/B000FJZYR0/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 .

     

    If your unit is really 3/4", Amazon also has similar fittings in 3/4".

  • in reply to rati89

    I'll be honest, there were a number of times when it rained and the barometric measurements didn't predict it in advance.

     

    So I am definitely leaning towards your friend's concept of using actual data from weather forecasts.  I imagine there would be a way to tap into this data by means of some IoT method.

    Time permitting, I would definitely like to look into this as I believe that water conservation is a worth while goal.