Group Project: Water Group Project: Water Turbidity MeterTurbidity Meter

Group BGroup B

OutlineOutline

Project Statement: “Design and construct a turbidity measuring and displaying device based on the HC08QY4 microcontroller”

Integral components are the microcontroller mentioned above, an LDR, an LED, and the 7 segment display

What is turbidity?What is turbidity?

Turbidity is a “measure of the collective optical properties of a water sample that cause light to be scattered and absorbed rather than transmitted in straight lines (USGS 04/96).”

The quantity of suspended solids in a water sample

Indicates how potentially polluted a water sample is

Our design:Our design:

LED functions as constant light sourceLED functions as constant light source LDR at set distance from LED measures light intensityLDR at set distance from LED measures light intensity Resistance of LDR varies according to intensity of light, Resistance of LDR varies according to intensity of light,

providing an indication of water clarityproviding an indication of water clarity Microcontroller records voltage drop over LDR every 15 Microcontroller records voltage drop over LDR every 15

secondsseconds Above measurement converted to a percentage of Above measurement converted to a percentage of

turbidity, displayed on 7 segment displayturbidity, displayed on 7 segment display 0% indicates perfect transparency (clean water); 100% is 0% indicates perfect transparency (clean water); 100% is

total light dispersion (very dirty water)total light dispersion (very dirty water)

Basic CircuitBasic Circuit

Basic processBasic process

System is calibrated prior to first useSystem is calibrated prior to first use Turn LED onTurn LED on Measure voltage over LDRMeasure voltage over LDR Convert voltage to percentage based on calibrationConvert voltage to percentage based on calibration Output percentage to display, hold until next readingOutput percentage to display, hold until next reading Wait 15 secondsWait 15 seconds Start process againStart process again

To the futureTo the future

Find more information on turbidity meter design in Find more information on turbidity meter design in generalgeneral

Adjust focus to now incorporate the specific software Adjust focus to now incorporate the specific software coding required for turbidity meter to function correctlycoding required for turbidity meter to function correctly

Develop code and produce functioning prototype circuitDevelop code and produce functioning prototype circuit

Test and adjust, trial and errorTest and adjust, trial and error

Questions?Questions?