Gravity: Analog pH Sensor/Meter Kit

This tiny little board features two chips from Maxim Integrated: MAX32664 and MAX30101. The 30101 Oximetry module  is the sensor on board responding for both oximetry and heart rate sesnsing. The MAX32664 is equipped with a Cortex M4 handling algorithimc calculations, digital filtering and automatic gain control. The board comes with I2C and SparkFun has provided to it Qwiic connectors for ease of use.

The module has two outputs: analog A0 and digital D0.
digital output D0 - signal 0 or 1 appears depending on the configuration of threshold.
The threshold is fixed with the potentiometer. Characteristic: - Operating voltage: 3.3V -5 V - Sensitivity adjustable by potentiometer
- Dual output mode: analog and digital
- Red LED - power indicator
- Green LED - digital switching output indicator
- Measurements PCB: 3 x 1.5 cm
- Sensor measurements: 5.4 x 3.9 cm

Encapsulated with water resistant stainless steel with sensor dimensions 5,5 * 50mm, cable length 100 cm.
DS18B20 Submersible Probe Sensor Temperature features:
- Based on the DS18B20 chip
- Supply voltage: 3 ~ 5.5V
- Consumption <5mA
- Measuring Range: -55 °C to 125 °C
- Accuracy: +/- 0,5ºC
- Outputs: - GND black
      - Red Vcc
      - Yellow digital output
- Inocidable steel
- Cable length: 1m

High sensitivity to Ammonia (NH3), Nitrogen oxides (NOx), Alcohol, Sulphides, Benzene (C6H6), CO2, smoke and other harmful gases.  The MQ-135 sensor is to sensible for other gasses in the air so that is not possible to get good values for CO2 from it.
MQ-135 Air Quality Sensor features:
- Main chip: MQ-135 natural gas sensor and comparator LM393
- Working voltage: 5V
- Current: 150mA
- Digital output: TTL 0/1
- Analog output: analog voltage sensing value
- Quick response features:
- Detection concentration:
   10ppm - 300ppm NH3
   10ppm - 1000ppm Benzene
   10ppm - 300ppm Alcohol
- Adjustable sensitivity with the potentiometer
- Size: 32mm x 20mmx 18mm

Imagine the simplicity of the Arduino One connected to the communication module. Seems too good to be true, right? That's Arduino One WiFi. Arduino Uno WiFi REV2 (ABX00021) with its integrated IMU (Inertial Measurement Unit) and WiFi is the ideal board to start making your first Internet application from scratch, or to use in the educational field. It has 14 digital input / output pins (5 of which are PWM outputs), 6 analog inputs, a 16 MHz ceramic resonator, an accelerometer, an RGB LED, a power connector and an ICSP header.

This detection module that allows you to detect your heart rate and blood oxygen level from your Arduino project. You can monitor your blood oxygen level yourself to avoid going to the doctor or pharmacy on purpose. Simply press the sensor with your finger and wait for the reading of hemoglobin (Spo2), heart rate and Perfusion Index (PI%). It is a solution as an integrated heart rate sensor and pulse oximetry, which includes two LEDs, a photodetector and is optimized for analog low noise optics.

This module includes the BMP280 component that converts atmospheric pressure, temperature and humidity with high precision into a digital signal.
The equipment uses the two I2C and SPI interfaces. The very good measurements made by the BMP280 allows the module to be used as an altimeter.
Its 5-pin straight connector allows easy connection to other electronic boards. BMP280 Temperature Barometric Pressure Sensor Module/SPI features:
- Interfaces:
       -I2C (up to 3.4 MHz)
       -SPI (up to 10 MHz)
- Supply voltage: 1.8-5VDC
- Module operating range:
       - Temperature: -40ºC to + 85ºC
0-100%
       - Pressure: 300-1100 hPa
- Resolution of the measures:
       - Temperature: 0.01ºC