Gravity: IO Expansion Shield for Arduino V7.1

The SparkFun micro:Climate kit is a complete weather station kit that builds on the weather:bit carrier board with weather and soil moisture sensors, all powered by the micro:bit. board.

MS01 works with SONOFF TH10/16 to accurately measure soil moisture and send data to your mobile phone. MS01 can regularly water and check soil moisture anytime and anywhere to make your flowers grow healthier. This is an accessory used in SONOFF TH10 / TH16.

Level sensor for liquids with float. The liquid level sensor acts as a switch. Liquid level float sensors are used when constant control and regulation of the liquid level (water, oil and other fluids) is required such as extraction pumps. The sensor is equipped with a float with a magnet which, acting by the buoyancy force of the fluid, moves along the tube, shortening or opening the reed switch. It can be used to detect liquid levels that are too high or too low. Ideal for all those applications where the level of non-corrosive liquids such as water tanks or aquariums needs to be monitored. It is made of stainless steel.

Level sensor for liquids with float. The liquid level sensor acts as a switch. Liquid level float sensors are used when constant control and regulation of the liquid level (water, oil and other fluids) is required such as extraction pumps. The sensor is equipped with a float with a magnet which, acting by the buoyancy force of the fluid, moves along the tube, shortening or opening the reed switch. It can be used to detect liquid levels that are too high or too low. Ideal for all those applications where the level of non-corrosive liquids such as water tanks or aquariums needs to be monitored. It is made of stainless steel.

MQ-8 Hydrogen Gas Sensor Module features:
- Main chip: MQ-8 methane 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:
  100ppm- 10000ppm hydrogen H2
- Adjustable sensitivity with the potentiometer
- Size: 32mm x 20mmx 18mm

Velostat or Linqstat film of pressure sensitive material ideal for DIY projects on Arduino, Raspberry or other platforms. When folded or creased it reduces its resistance allowing for flexible sensors.

NTC thermistor - with a negative temperature coefficient, i.e. an increase in temperature causes a decrease in resistance.   Thermistor NTC 10.0K 5% MF52A epoxy resin coating resistor features:

Size: 3mm
Rated resistance: R25 = 10.0k
B value 25/85 = 3950°K
Rated power: ‰¤ 50mW
Tolerance:± 5%
Operating temperature: from -40°C to +125°C  Tinned steel wire 25mm

The MAX9812 is a sound amplifier specially designed to treat the signal coming from microphones.
We can use it together with Arduino to measure sound from a processor like Arduino.
When we saw the modules with microphone we commented that, in general, the signal generated is too low to be registered correctly.
If we want to be able to measure sounds, we will have to amplify the signal. The MAX9812L has single / dual inputs, fixed gain of 20dB, bandwidth of 400 kHz, low noise and low signal distortion 0.015% THD.
There are two models, its supply voltage is 2.7V to 3.6V.
We can use the sensors with MAX9812 for applications that require measuring the intensity or frequency of the sound.

The accelerometer sensor is an add-on for your RedBot that provides shock and motion detection. The sensor works by measuring acceleration forces on the x, y and z axes. By measuring the amount of acceleration (or lack thereof), your robot can better understand its movements.

Precision Temperature Sensor TO-92 LM335 LM335Z-ST features:
- Power supply from 5 to 30 Vdc
- Connection through analog input
- Temperature range from -40ºC to 100ºC
- Linearity +10 mV / ºK
- Accuracy of measurement: ± 2 ° C
- Manufacturer: Texas Instruments