Build Instructions

The sensor is designed to be as easy to build as possible, you'll only need a craft knife and a screwdriver to complete the housing.

Bill of Materials

Board and sensor

Housing

Junction Box with Grommets Waterproof IP56 - £7.55
American Marine Pinpoint ORP / REDOX Calibration Fluid - £7.99
M3 A2 Stainless Steel Pozi Countersunk Machine Pozi CSK Screws Bolts - £5.44
USB A Jack to Micro USB B Jack Round Panel Mount Adapter - £5.50
BNC Coupler Adapter Insulated Female To Female Panel Mount - £3.99
Micro USB Type B Male To Micro B Male 5Pin OTG Adapter Converter Lead Data Cable - £2.99
BNC male to BNC male pigtail coax cable RG316 30cm 089 - £4.45
USB 2.0 A Male to A Male Cable, 5m Grey - £2.50
3 Pin Plug USB Mains Charger Adapter, 1AMP - £7.79

Cost of sensor & housing = £145.

The lowest cost equivalent I could find was Atlas Scientific Pool Kit at $280 USD, but that is IP64 rated and has a PH sensor as well.

Assemble the sensor:

Attach the ORP sensor to the Seeduino using a Grove cable (into A1)
Push the shield into the haders onto the Seeduino, taking care to feed the grove cable for the ORP sensor between the sheild and board
Use a craft knife to cut holes into the rubber grommits for the USB panel adaptor and BNC adaptor and thread in the adaptors into the holes
Connect the USB panel adaptor and BNC adaptor using the micro usb cable and the BNC cable to the respective boards
Screw the arduino to the case

Job done.

## Build Notes

At time of purchase, I would rather have bought a Mirco-USB panel adaptor, but they were sold out. Get one of these if they are in stock and then you can use a sealed Micro-usb power supply to the unit. Micro USB panel adaptor.
The ORP sensor board has a tiny screww hole, so it's not fastened in the box as I couldn't find a screw to accomodate it.
The Wifi shield is expensive, a better choice is probably Seeed UART Wifi V2.
Similarly a Pi Pico and Grove shield might be a better board choice.