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DFRobot

· MPN: KIT0131

$540.90 |
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Build a DIY water quality monitor for field studies, teaching or environmental projects with the KnowFlow Basic Kit. This Arduino-based kit measures two key ...

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Build a DIY water quality monitor for field studies, teaching or environmental projects with the KnowFlow Basic Kit. This Arduino-based kit measures two key water parameters: pH and electrical conductivity (EC).

Data can be recorded automatically to a micro-SD card for later analysis, and the Bluno controller provides built-in Bluetooth so readings can be viewed from a smartphone. The kit is based around the DFRobot Gravity sensor ecosystem, making it easy to modify or expand with additional modules.

This basic version includes pH and EC sensing only. For temperature measurement, add a compatible waterproof DS18B20 sensor kit separately. DFRobot recommends using a 200mmx150mmx75mm waterproof case and an acrylic plate to mount the KnowFlow sensors.

Included: Bluno (DFR0267) x1; Gravity: Analog pH Sensor / Meter Kit For Arduino (SEN0161-V2) x1; Gravity: Analog Electrical Conductivity Sensor / Meter For Arduino (DFR0300) x1; Gravity: IO Expansion Shield for Arduino V7.1 (DFR0265) x1; Gravity: I2C SD2405 RTC Module (DFR0469) x1; MicroSD card module for Arduino (DFR0229) x1; Gravity: Analog Signal Isolator (DFR0504) x1; SD/MicroSD Memory Card (16GB Class10 SDHC with Adapter) (FIT0394) x1; Analog sensor cable x2; Digital sensor cable x1.

Features:

  • pH, EC auto record
  • Micro-SD Local storage
  • Extensible design
  • plug and play
  • Bluetooth built-in

Specifications:

  • Bluno Microcontroller: Included
  • On-board BLE chip: TI CC2540
  • Wireless Programming: via BLE
  • BLE configuration: Support AT command to config the BLE
  • Serial communication: Transparent communication through Serial
  • BLE firmware: Upgrade BLE firmware easily
  • DC Supply: USB Powered or External 7V~12V DC
  • Microcontroller: Atmega328p
  • Bootloader: Arduino Uno (disconnect any BLE device before uploading a new sketch)
  • Pin mapping: Compatible with the Arduino Uno pin mapping
  • Size: 60mm * 53mm (2.36"*2.08")
  • Weight: 30g
  • pH sensor: Included
  • Module Power: 5.00V
  • Module Size: 43 x 32mm (1.69x1.26")
  • Measuring Range: 0 - 14PH
  • Accuracy: ± 0.1pH (25 ℃)
  • Response Time: ≤ 1min
  • pH Sensor: with BNC Connector
  • Interface: pH2.0 Interface (3 foot patch )
  • Adjustment: Gain Adjustment Potentiometer
  • Indicator: Power Indicator LED
  • EC sensor: Included
  • Operating Voltage: +5.00 V
  • PCB Size: 45 × 32mm(1.77x1.26")
  • Measuring Range: 1ms/cm -- 20ms/cm
  • Operating Temperature: 5 - 40 ℃
  • Accuracy: ±10% F.S (using Arduino 10 bits ADC)
  • Interface: PH2.0 Interface (3-pin SMD)
  • Conductivity Electrode: Electrode Constant K = 1,BNC connector
  • Cable Length of the Electrode: about 60cm(23.62")
  • Indicator: Power Indicator
  • Analog Signal Isolator: Included
  • Operating Voltage: 5.0V
  • Response Time: 4 seconds (Typ)
  • Analog Error (both ends): ± 20mV (Typ)
  • Interface Type: PH2.0-3P
  • No load Current: 75mA
  • Dimension: 42 * 32mm / 1.65 * 1.26 inch
  • Non-isolated Terminal: Arduino Side
  • Supply Voltage: 5.0 ± 0.1V
  • Analog Output: 0 ~ 5.0V
  • Isolated Terminal: Sensor Side
  • Output Voltage: 5.0 ± 0.2V
  • Analog Input: 0 ~ 5.0V

A good fit for water quality investigation, pollution sourcing, environmental education and open science projects using Arduino-compatible hardware.

Jargon buster

Plain-language definitions for the technical terms used above.

ADC
An analogue-to-digital converter reads a changing voltage and turns it into a number the microcontroller can use. It matters when connecting analogue sensors such as light, sound, or variable-resistor sensors.
Analog signal isolator
A circuit module that passes an analog reading while electrically separating the sensor side from the microcontroller side. This can matter in water monitoring because probes in the same liquid can interfere with each other or create ground-loop errors.
ATmega328P
An 8-bit microcontroller chip used on many Arduino Uno-compatible boards. Knowing the controller uses an ATmega328P helps you understand its memory, speed, pin compatibility, and the Arduino sketches it can run.
BLE
BLE stands for Bluetooth Low Energy, a Bluetooth mode designed for low power use and broad compatibility with modern phones and computers. It connects well to battery-powered and mobile devices, including Apple hardware, though it behaves differently from Bluetooth Classic and its serial-style profiles.
BNC connector
A twist-lock connector commonly used for probes, test equipment, and shielded signal cables. For pH and conductivity sensors, a BNC connector makes it easier to attach or replace electrodes without soldering.
Bootloader
Small starter software on a microcontroller that lets new code be uploaded before the main program runs. Knowing how to enter bootloader mode matters when you need to program the board or recover it after a faulty sketch.
DC
DC means direct current, where electricity flows in one constant direction, as supplied by batteries, USB ports and many plug-pack power supplies. When a product specifies DC, it runs from a DC supply rather than mains AC, so you need to provide the correct voltage and polarity.
DS18B20
The DS18B20 is a common digital temperature sensor, often supplied in a waterproof stainless-steel probe, that sends its readings to a microcontroller over a 1-Wire connection. It is a typical choice for adding temperature data to environmental or water-monitoring projects.
Electrical conductivity (EC)
A measure of how easily water conducts electricity, usually related to the amount of dissolved salts or minerals in it. EC matters for water quality projects because it helps indicate contamination, salinity, or nutrient levels, but it does not identify the specific substances present.
Gravity
Gravity is DFRobot’s plug-in connector system for sensors, motors and modules, using standard cables to reduce loose jumper wiring. It matters because Gravity-compatible parts can connect directly to these ports, while non-Gravity parts may need adapters or manual wiring.
I2C
I2C is a two-wire communication bus used by many sensors and small modules. It matters because several I2C devices can share the same two wires, but each device needs a compatible address and your controller must support I2C.
LED
A light-emitting diode (LED) is a small electronic component that emits light when current flows through it in the correct direction. Because it only conducts one way, its polarity matters, and a through-hole LED must be soldered the correct way around to light up.
microcontroller
A microcontroller is a small computer on a single chip that runs a stored program and controls connected inputs and outputs such as buttons, sensors, displays and communication interfaces. In a device built around one, it is the part that executes the code and coordinates the device's behaviour.
microSD card
A microSD card is a small removable flash memory card used to store data such as audio, images, logs or program files. Its capacity and formatting (often FAT32 or exFAT) affect how much can be stored and whether the card needs preparing before use.
PCB
A printed circuit board (PCB) is a board, usually rigid, with etched copper tracks that connect electronic components together without loose wiring. Components are mounted on the board and signals route between them through the copper layout.
pH
A measure of how acidic or alkaline a liquid is, on a scale where 7 is neutral. For a water monitoring kit, pH tells you about water chemistry and whether the included probe matches the range and accuracy your project needs.
potentiometer
A variable resistor usually turned with a knob or shaft to create an adjustable electrical signal. It is often used for inputs such as volume, brightness or position, so it helps beginners learn how a microcontroller reads changing values.
RTC
A Real-Time Clock keeps track of time even when the main processor is asleep or powered down, usually with a small backup battery. It matters for data logging and tracking projects that need accurate timestamps.
SD2405
A real-time clock chip used to keep track of date and time even when the main controller is not actively running. In a data-logging kit, it helps timestamp measurements so readings on the memory card can be matched to when they were taken.
Shield
An add-on board that plugs into a main controller board to give it extra features such as sensing, motor control or communication. Knowing a product supports shields helps you judge whether it can connect neatly into an existing maker-board setup.
SMD
SMD means surface-mount device, a component style designed to be soldered directly onto the surface of a circuit board rather than through holes. SMD parts are compact and mounted flat on the board, which suits smaller and mass-produced designs.
TI CC2540
The TI CC2540 is a Texas Instruments system-on-chip that combines an 8051 microcontroller core with a Bluetooth Low Energy (BLE) radio, used to add short-range wireless communication to embedded projects. It lets a device connect to a phone or another BLE device to exchange data or be configured wirelessly.
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