DS3231 Precision RTC Real Time Clock Module AVR ARM

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.

This module is used to extend the Raspberry's 40 GPIO pins to another set of 2x20 male pins and 8 parallel pins accessible on the terminal blocks in the that test leads are pushed. The electronic board offers great reliability with the Raspberry and is very easy to connect thanks to its existing suitable accessories but not included.
The module offers a set of mini jumpers to configure the GPIO.
The press to release the two terminal blocks of 20 connections is very easy to use. Raspberry Pi 2-3 Model B Multifunction Expansion GPIO Module features:
- Communication connections: 1 TXD0 (emission) and 1 RXD0 (reception)
- Power connections: 5 of 3.3V, 2 of 5V and 5 of GND
- Connections for pulse width modulation ( PWM): 2
- GPIO connections: 11

Sense HAT is your absolute classic used for a well-known and popular Astro Pi projects. It features set of sensors (Pressure, humidity, IMU and temperature) and a great 8x8 LED screen. It is a full set for your Raspberry - you can both measure your projects environment, display it on the screen as well as manouver and input data with joystick and buttons included on the HAT.

16 servo motors with one board seems impossible? With this board not only it isn´t impossible, but it even seems easy. Additionally, you won´t need to sacrifice any of your valuable GPIOs as the HAT connects directly via I2C. Additionally, you have a serial terminal connection at your disposal.

You can supply the power to the board through your Pi or directly if you are going for larger servos and would need a separate source of power. Simply scrap a small blob of solder on the isolation jumper.

This touch HAT for Raspberry Pi will inspire your next interactive project with up to 12 capacitive touch sensors, from fruit keyboards to interactive lighting.

Pimeroni Display-O-Tron is one of the most popular and at the same time easiest to use HATs in Pimoroni offering. It is featured with 16x3 character LCD supporting a complete ASCII character set. The shield is powered directly through the Pi board. The board comes with multiple capactive touch pads on top of that. All functions of the shield are accessible in a really straight forward way and supported by a range of Python libraries available on github and officially issued by Pimoroni. The hat is compatible with all Raspbery boards given its universal 40 GPIO pinout

Pimeroni Unicorn HAT is one of the most popular and at the same time easiest to use Raspberry HATs in Pimoroni offering. It is featured with a matrix of 64 RGB LEDs powered directly through the Pi board. The applications of the HAT spread from just a simple games in the classroom up to color indications in your robot. All of this accessible in a really straight forward way and supported by a range of Python libraries available on github and officially issued by Pimeroni. The hat is compatible with all Raspbery boards given its universal 40 GPIO pinout

Raspberry Pi Pico HAT Expansion is an input/output expansion board designed for Raspberry Pi Pico, which provides a set of 2x20 pin headers in the form of Raspberry Pi header along with a set of 2 x 20 pins. It allows any HAT designed for Raspberry Pi to be connected to Raspberry Pi Pico.

The Qwiic HAT is an absolute basic of Qwiic system for Raspberry. It enables a quick and efficient connection of an sensor to your Raspberry over I2C bus (GND, 3.3 V, SDA and SCL). As Qwiic enables daisy chaining of components, you can pretty much install as many sensors on the Qwiic HAT as you want. On top of that it fits perfectly Pi Tin enclosure from SparkFun enabling connection while in case.

This Serial Expansion HAT provides a 2-channel I2C and UART interface with 8 programmable GPIO Pins where you can connect more accessories and add-ons.