Bluetooth Connected Turbidity Meter

Hold handle and lower sensor into water without overflowing  into the coupler

Background

I needed turbidity values for a project I was working on so I decided to make an instrument that I could use universally.

BOM

The meter consists of:

• A turbidity sensor and sensor interface board from DFROBOT. There are links on this site to more technical information. A data sheet on the turbidity sensor.
• A Feather 32U4 Bluefruit LE module.

Packaging

The sensor waterproof housing and base

Sensor mounted to base which is glued to coupler

Electronics acrylic covering and wiring

The handle

The photos shows the approach which was to house the sensor down in a waterproof cylinder that is lowered into the water. The acrylic handle houses the electronics. 

• A PVC coupler is the housing.
• A circular acrylic base was cut and is glued to the bottom of the coupler with "Plumbers Goop (PG)" (my favorite glue :)).
• The base has hole drilled that fits the sensor and the sensor has an Oring fitted and then is screwed with sheet metal screws to the base. The screws are sealed with PG as well.
• The base is glued to a 90 degree acrylic bracket with acrylic cement.
• The housing is glued to the bracket with PG.
• The bracket is fitted with an acrylic cover to provide a handle and some protection for the electronics.
• The acrylic peices were bent on my "acrylic bender".

Hookup

The analog output of the turbidity sensor board is connected to the Feathers A0 analog input pin.

Power to the turbidity sensor board is provided by the VBUS power on the Feather.

Code

I used the code that Adafruit provided on the tutorial site using the blueart_cmdmode sketch.

Phone app

I used the Adafruit Bluefruit LE Connect mobile application.

Assy and test

I simply followed the Adafruit tutorial for reading analog values using the mobile app and had no problems getting a continuous reading to my phone from the turbidity sensor.
Make sure that you have the switch on the sensor interface board in the analog position.
Enjoy:
Maker Don