Measurement Velocity at Weir With Distance Sensor




Introduction: Measurement Velocity at Weir With Distance Sensor

We made a device what calculated the water velocity over a weir. This is measured by two distance sensors.

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Tools, Materials and Skills

You will need the following materials

  • Photon kit
  • 6 long electric wires
  • 10 small electric wires with pins
  • 2 sharp distance measuring sensor unit
  • Wooden plank at 10 cm more than the width of the weir
  • Wooden plank at 15-20 cm
  • 10 screws
  • sheet of plastic

You will need the following tools:

  • screwdriver
  • soldering iron
  • Ducttape
  • measuring tape

You will need the following skills

  • Soldering
  • using a screwdriver
  • Programming on Photon (

Step 2: Building Your Measuring Device

First we will make the framework for the sensors and the Photon.

Take two wooden planks and connect those two onto each other with screws like you see on the picture. After you done this you can put the distance sensors on one of the wooden planks. Make sure the sensors are 12 cm away from each other from the middle to the middle. Turn the wooden planks over and connect your photon frame to the other plank with duct tape.

Hang the sheet of plastic in the water stream to make the top visible to the sensor.

Step 3: Connect the Wires With the Sensors and Photon

Now we are going to connect the photon properly with the sensors. First take 6 small electric wires and cut them in half. Now strip some of the plastic at the end of the wires. Remove the plastic at the end of the long electric wires.

Turn on your soldering iron and connect the small electric wires with the long electric wires. You should get now 6 long wires with pins on one end. Solder the open end of the long wires to the wires of the distance sensors. Put some tin on the wire ends you made so it will be connected properly and finish it with some duct tape to prevent short circuiting . Close to the sensor you should have 3 different colours normally red, black and yellow. Put the red wires end on the + part of the photon frame and the black wires on the - part of the photon frame. now take one small red wire and connect this one with the 3v3 input and the + part of the photon. Take also a black wire and put this one from GND to the - part of the photon. The last thing you have to do is to put the yellow wires to the A0 and the A4. On the picture you can also see where which wire should be.

Step 4: Writing the Code

To get the information out of the sensors we use

Use a code similar to the code given above to get the best results!

Be the First to Share


    • Backyard Contest

      Backyard Contest
    • Silly Hats Speed Challenge

      Silly Hats Speed Challenge
    • Finish It Already Speed Challenge

      Finish It Already Speed Challenge



    2 years ago

    That's a neat setup :)