Connectors

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It used to be that in order to add sensors or components to your project you had to use a breadboard or do soldering. However in the past decade companies have begun to offer connectors which let you easily connect / disconnect components to your project without a breadboard or soldering.

A major benefit of these connectors is that it makes it much more accessible for beginners. And experienced people can also benefit since it becomes much easier and quicker to prototype and build interesting projects.

On this page we describe some of the more popular connectors in use today.

Grove

Introduced by Seeed Studio in 2010, Grove uses a proprietary 4-pin 2.0mm pin pitch connector for its range of boards and boards made in partnership with Arduino. The Grove connector can be used with analog, PWM, digital IO and I2C.

While almost the same as a JST PH connector, Grove unfortunately is not compatible - they are physically too different for JST PH and Grove to be inter-changeable.

Additional References on comparision of Grove to JST PH

As Grove has been around the longest, there are a large number of components available.

Many Grove components can be used with Adafruit hardware.

Grove is is only compatible with STEMMA I2C components.
Analog, PWM and digital IO are not compatible.
If a component has SDA / SCL pins, then it is an I2C device.

Seeed Studio makes a Grove - QWIIC Hub to support interoperability with Sparkfun QWIIC and Adafruit STEMMA QT.

Description

Different from our Grove system, QWIIC is an I2C interface system initiated by Sparkfun around 2017, using a 4pin JST SH 1.0mm connector. STEMMA QT initiated by Adafruit is cross-compatible with QWIIC, as they use the same connector/cable. To better support different types of interface systems, we provide Grove - QWIIC Hub, which enables you easily connect the I2C devices with Grove/QWIIC/STEMMA QT interface, get the best use of your devices/controller of different interfaces.

Additional References

Youtube: Grove 10th Anniversary Documentary 12/31/2020

JST

JST is an acronym for the company Japanese Solderless Terminals. They pioneered the first solderless connectors.

From_the_archive

J.S.T. = Japanese Solderless Terminals As our company name implies, Solderless Terminal, has real significance. When JST was established in 1957, we were Japan's first manufacturer and distributor of Solderless Terminals.

There are many types of JST connectors, but the two most commonly used by Adafruit are:

JST Series "PH" 2.00mm pin-to-pin pitch
- Used with STEMMA
JST Series "SH" 1.00 mm pin-to-pin pitch
- Used with QWIIC and STEMMA QT

Here's a great video from Jan 5, 2021 where Lady Ada talks about JST SH and PH Connectors:

The Great Search: JST Connectors SH and PH
- 0:57 JST PH great for power - Sparkfun originally started LiPo Battery JST PH connectors and it became a Maker standard.
- 2:34 JST SH - Sparkfun also originated QWIIC for breakout boards (STEMMA QT compatible with QWIIC)
  - Used for I2C (I2C has become the standard for sensors - rarely see sensors over SPI anymore)

QWIIC

QWIIC is an I2C interface system introduced by Sparkfun in 2017, using a 4pin JST SH 1.0mm connector.

STEMMA QT was introduced by Adafruit in 2018. STEMMA QT is cross-compatible with QWIIC because they use the same connector/cable.

The I2C protocol enables components to be daisy chained together.

QWIIC connectors can be found on many of SparkFun’s boards such as the MicroMod ATP carrier board which uses an M.2 slot, the MicroMod standard, for interchangeable processor boards such as the ESP32, Artemis and the new RP2040. There are also adapters for using QWIIC components on the Raspberry Pi via a HAT and pHAT and for the Arduino range of boards. With SparkFun’s QWIIC connector we can easily connect sensors such as the HC-SR04 ultrasonic sensor, soil moisture sensor and even a NEO-M9N GPS breakout.

STEMMA

STEMMA standard is not plug-compatible with STEMMA-QT

STEMMA

JST PH 3 and 4 pin connectors (2.0mm pitch connectors)
- 4 pins - I2C
  - Enable the use of multiple sensors / devices on a single bus thanks to devices having an address
- 3 pins - PWM/Analog/Digital
  - Control Neopixels
  - Read analog sensors
  - Use digital IO devices such as LEDs and buttons
Connector is keyed so that it cannot be inserted incorrectly
STEMMA is seen on larger boards such as PyPortal
Aims to be compatible with Grove/Gravity

** Additional References **

Adafruit STEMMA info page

STEMMA is a plug-and-play board and sensor system that lets you quickly plug together various devices and accessories, without any soldering! STEMMA uses 3-pin cables for simple analog and digital devices, like relays and buttons. For more complex sensors and displays, we use a 4-wire I2C connection. For larger boards and devices we use a Grove-compatible connector, for smaller ones we use a QWIIC-compatible connector called STEMMA QT.

As all STEMMA sensors have level shifting and voltage regulation, you can use them safely with any 3 to 5V power and logic device - from microcontrollers like Arduino-compatibles, to full Linux single board computers like the Raspberry Pi. We even have USB to I2C adapters that let you connect STEMMA devices directly to a computer without any microcontroller programming required! Then, use our Arduino or CircuitPython/Python libraries and examples to easily get your electronics project working on any platform with STEMMA and STEMMA QT.
Adafruit Learn Guide: What is STEMMA?
Awesome list for STEMMA and STEMMA QT

STEMMA QT

STEMMA is not plug-compatible with STEMMA-QT

STEMMA QT (‘cutie’)

JST SH (1.0mm pitch connectors)
4 pins - I2C only
About half the size of STEMMA
- great for smaller boards such as Adafruit QT Py
Cross-compatible with SparkFun QWIIC

Examples of STEMMA QT boards

Additional References

Adafruit STEMMA info page

STEMMA is a plug-and-play board and sensor system that lets you quickly plug together various devices and accessories, without any soldering! STEMMA uses 3-pin cables for simple analog and digital devices, like relays and buttons. For more complex sensors and displays, we use a 4-wire I2C connection. For larger boards and devices we use a Grove-compatible connector, for smaller ones we use a QWIIC-compatible connector called STEMMA QT.

As all STEMMA sensors have level shifting and voltage regulation, you can use them safely with any 3 to 5V power and logic device - from microcontrollers like Arduino-compatibles, to full Linux single board computers like the Raspberry Pi. We even have USB to I2C adapters that let you connect STEMMA devices directly to a computer without any microcontroller programming required! Then, use our Arduino or CircuitPython/Python libraries and examples to easily get your electronics project working on any platform with STEMMA and STEMMA QT.
Adafruit Learn Guide: What is STEMMA QT?

We like the JST PH 2.0mm pitch cables because they are cross-compatible with Grove/Gravity. But they're a bit large for smaller breakout boards and wearables. So, for smaller I2C devices, we'll use the JST SH that SparkFun QWIIC uses, so that QWIIC & STEMMA QT sensors are cross-compatible!
https://www.youtube.com/watch?v=6GXRRuFuFy0
From the Adafruit STEMMA & STEMMA QT Plug & play connectivity - STEMMA Sunday video 7/28/2019 description

STEMMA started in 2014, intended to be compatible with Grove (cause Grove is all that existed at the time - since 2010) QWIIC started in 2017, STEMMA-QT added so that could use the smaller connectors. In addition - on the comparison page it states that Grove is a proprietary 4 pin 2.0mm pitch connector. STEMMA attempts to be as cross-compatible as possible with both Grove and Gravity (compatible connectors & 3-5V power/logic). STEMMA QT is cross-compatible with QWIIC - STEMMA QT connector/cable is same as QWIIC. You can use STEMMA QT devices with QWIIC devices/controllers. There is also a table which outlines the compatability matrix.

Also explains the differences to Grove and QWIIC
Adafruit Learn Guide: What is STEMMA QT?
Awesome list for STEMMA and STEMMA QT

STEMMA, QWIIC and Grove Connectors: Which is Right for You?

Depends on what boards you already have

Adafruit boards usualy have some form of STEMMA / STEMMA QT connector
- STEMMA QT is completely cross-compatible with Sparkfun QWIIC
- STEMMA is different from STEMMA QT/QWIIC, aims to be compatible with Grove I2C
Seeed Grove connectors work with multiple platforms
- Arduino
- Raspberry Pi
- Raspberry Pi Pico

Connector Comparison

Device	Manufacturer	Connector	Voltage / Logic	Protocols	Year Introduced	Compatible
Grove	Seeed Studio	Proprietary 4 pin 2.0mm pin pitch	3-5V DC	4 Pin I2C / Analog / Digital / PWM	2010	Compatible with STEMMA I2C only
QWIIC	Sparkfun	JST SH 4 pin 1.0mm pin pitch	3V DC	I2C	2017	N/A
STEMMA	Adafruit	JST PH 3 Pin or JST PH 4 Pin 2.0mm pin pitch	3-5V DC	4 Pin I2C or 3 Pin Analog / Digital / PWM	2014	Only STEMMA I2C (JST PH 4 Pin) compatible with Grove
STEMMA QT	Adafruit	JST SH 4 pin 1.0mm pin pitch	3-5V DC	I2C	2018	intended to be compatible with QWIIC

Reference: Toms Hardware STEMMA vs QWIIC vs Grove Connectors 4/24/2021

Note

An Adafruit Learn Guide has a table which outlines the cross-compatability matrix.

Additional References

https://blog.adafruit.com/2023/12/12/the-electronic-connector-book-and-online-reference/

This page was last updated on 2023-12-13 15:45:07 -0500.