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KdUINO Turbidity Monitor

Sensor Testing/QC

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Turbidity Challenges

Commercial equipment is expensive
No reliable, cheap, automated makerspace sensors

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The KdUINO Concept

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Wiring Review

TCS34725 (light sensor)

Last Class: soldering headers to light sensors so they could be wired to the mux switches.

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Quality Control Testing

Done Since We Met

Tested each light sensor
Re-soldered a couple that failed the test
Ran them all through the ultrasonic cleaner
Hand-cleaned a few that still had some flux residue

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Today’s Challenge:

Replicate Mr. O’Fo’s Testing

Recheck sensors since cleaning: WHY?

Double-check Mr. O’Fo’s work
Check sensors/soldering post-cleaning
Learn the process for future use in the project

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TODAY’S PLAN

Gather Test Materials (Slide 8)
Set Up for Testing (Slides 9-13)
Run the Test (Slides 14-15)
Determine Test Results (16-17)

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Gather Test Materials

Component	Qty
Arduino UNO + solderless breadboard	1
TCS34725 Light Sensor	1-3
Dupont Jumper Wires M x M	5
Computer with Arduino IDE software	1
USB cable to connect UNO to Computer	1
Test Sketch -> Test_TCS34725_ForrestTech.ino	1
Procedures Cheat Sheet	1

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Set Up for Testing

VIN (17)

GND

(18)

SCL (20)

SDA (21)

LED (23)

Mount the Sensor into the breadboard using the header pins.
Place it so breadboard spots adjacent to the header pins are available.
Note that the PIN names are now hidden.

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Set Up for Testing (cont.)

4. Cross-connect the UNO (MCU = microcontroller) pins to the Sensor pins using dupont terminated wires per the wiring plan 1st 4 pins only!

Wiring Plan
MCU	Sensor
5V	VIN
GND	GND
SDA	SDA
SCL	SCL
GND	LED

Don’t connect this one yet!!!!!!!!

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Set Up for Testing (cont.)

Ready for software upload…

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Set Up for Testing (cont.)

5. Open the Arduino IDE.

6. Open the Test Sketch: Test_TCS34725_ForrestTech.ino

7. Connect the USB between PC and the UNO – you should see lights on your UNO and a light on the sensor.

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Set Up for Testing (cont.)

8. Ensure your settings are correct in the Arduino IDE:

See top menu…TOOLS…
Board: Arduino AVR Boards“Arduino UNO”
Port: <select the port with UNO>

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Run the Test

9. Open the serial monitor

10. Upload the sketch!

Set baud rate to 115200

Select Autoscroll

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Run the Test (cont.)

11. Cross-connect the last pin: GND to LED

You should see the LED go out
You should see the LUX (and other) values in the serial monitor change – they should be much lower

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Determine Test Results

PASS		FAIL
LED illuminates steadily – prior to connecting LED to ground – the light does not flicker		The LED does not stay illuminated steadily - it flickers
The serial monitor reports that the sensor is found		The serial monitor reports no sensor found
LUX values are reported by the serial monitor		No lux values reported in the serial monitor
LED goes off once connected to Ground		LED remains lit when connected to ground
Lower LUX values are reported by the serial monitor when the LED is connected to ground		Lux values don’t change when the LED is not lit

A sensor must pass ALL tests in order to PASS

Please alert us to any sensor you find that fails ANY of these tests.

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Determine Test Results (cont.)

Place Sensors in Boxes

PASS		FAIL
Sensors that pass testing will go on to the next step in the building process. Mr. O’Fo will attach wiring and encapsulate them in the potting resin.		Sensors that fail testing will be returned to Mr. O’Fo for troubleshooting. He will probably resolder and try again.

A sensor must pass ALL tests in order to PASS

Please alert us to any sensor you find that fails ANY of these tests.

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Overall Build Plan

✅ Assemble a solderless breadboard test of all the components

Install the light sensors in epoxy resin
Retest the light sensors!!!
Test fit of the PVC pipe structure
Install & connect the wiring between the sensors and MCU
Retest!!!
Assemble the PVC pipes and fittings; make final connections
Live Test!!!