SparkFun Pi Servo HAT - Obsolete

This fingeprint scanner from ADH-Tech combines a highly precise fingerprint sensor module with an onboard MCU and UART interface enabling trivially very connection to any project.

The scanner independently reads and analyses the fingerprint thanks to an MCU algorithm that can send a converted digital signal to a peripheral serial interface for a data read. The onboard MCU algorithm enables operations such as for example a fingerprint enroll.

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.

QWIIC is a connection standard developed by Sparkfun enabling a quick an easy connection of peripherals without a need to solder pins, without any mismatches due to polarized connector. And on top of that you can "daisy chain" them! 

This hat pretty much opens the whole QWIIC universe in front of your Pi. It features 4 QWIIC ports all on the same I2C bus (GND, 3.3V, SDA, and SCL).

A universal  2x20 GPIO makes it compatible with all Raspberry Pi boards, as well as Google Coral and Jetson Nano.

Note:  For a secure connection in some applications, you'll need to add a pair of 1x20 stackable headers to extend the pins to your cart.

Expansion Board GPIO Shield 40 Raspberry Pi B+ Pin features:
- Shield module for Raspberry Pi 2 and Pi 3, B and B +

The kit includes 40 basic sensors, which will help you to easily kick-start any project. The sensors are featured with a proprietary Seeed Grove connectors enabling easy connection without soldering and a comprehensive guide book with exemplary classes.

If you are into prototyping with your Raspberry (which you should be given that is what the board is for), Pimeroni Explorer HAT Pro is a great solution for you. Board is equipped with a range of inputs and outpu, which enables it to achieve range of potential applications from controlling motors, to analog sensors and 5V systems. As any Pimeroni accessory it is well compatible with all Raspberry boards and comes in with a range of Pythong libraries on github issued by Pimeroni team themselves

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.

This starter kit aims to quickly get you connected to Seeed Studio BeagleBone® Green. It contains 10 Grove modules and we provide you with 3 step-by-step projects to get you started quickly with all modules. The set comes in a handy box and is attractively priced!

DS3231 Precision RTC Real Time Clock Module AVR ARM features:
- Can be used in projects of Arduino, Raspberry Pi, PIC, AVR
- Function compatible with the DS 3231
- Power supply voltage: +2.3 V to +5.5 V
- Temperature range: -40 ° C to + 85 ° C
- Low energy consumption
- Full clock calendar functions that include seconds, minutes, hours, date, month and year and valid until leap year compensation
- Two alarm calendar
- Interface: I2C

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.