Hc Sr04 – Hardware details

Pinout

Click here for a high resolution image of the pinout.

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Pin details

Pin Marking	Pin Name	Description
VCC	Power	Supply voltage (5V)
GND	Ground	Common ground for power and signals.
ECHO	Echo	Pin that receives the reflected wave
TRIG	Trigger	Pin that emits the start pulse
3V3	Power	Supply voltage for the UPDI
UPDI	UPDI	Communication pin for UPDI

⚠️

UPDI stands for Unified Program and Debug Interface. It is used to program and debug Atmel devices. The atmel chip on this board is used for the easyC I2C communication only. DO NOT try to use this for sensor communication!

ℹ️

This sensor is made to work specifically with the Qwiic connector; the echo and trigger pins are pre-connected.

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Qwiic (formerly easyC)

ℹ️

This board is fully Qwiic-compatible! Just plug it into your board using a Qwiic/easyC/STEMMA QT cable and start coding!

Qwiic (formerly easyC) details and specifications

Learn about hardware specifications, compatibility, and usage of the Qwiic connector.

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Dimensions

• Board Dimensions: 45 x 22 mm (1.8 x 0.9 inch)

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Address selection (Qwiic version)

This board contains hardware address switches. See below for instructions on changing the breakout board's address:

Address	SW3	SW2	SW1
0x30	0	0	0
0x31	0	0	1
0x32	0	1	0
0x33	0	1	1
0x34	1	0	0
0x35	1	0	1
0x36	1	1	0
0x37	1	1	1

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Hardware repository

Schematics, KiCad files, Gerber files and more can be found in the GitHub repository:

Ultrasonic sensor with easyC Hardware design

GitHub hardware repository for this product

The hardware repository contains everything you need to understand, modify, or manufacture the board. The different output folders are versioned. You can determine your board version by checking the version mark on the PCB.

Below is an overview of the available files.

CAD files

We use KiCad, an open-source PCB design tool. You can open and edit the .kicad_pro project file, which includes both the schematic and PCB layout.

The PANEL files are used internally for production.

Schematic

The OUTPUTS folder contains the schematic in .pdf format, exported from KiCad.

BOM (Bill of Materials)

The bill of materials (BOM) is provided in two formats:

• A standard .csv table, listing all components, part numbers, and values.
• An interactive BOM (.html) that visually highlights each component on the PCB, making it easy to locate and reference parts.

3D files

A 3D model of the PCB is available in .step format, allowing you to inspect the board design in CAD software.

Gerber files

Gerber files are essential for PCB manufacturing, as they contain precise instructions for each layer of the board. The repository includes standard Gerber outputs in a .zip file, such as:

• Copper layers (.Cu.gbr) – Defines the traces and pads on the board.
• Solder mask layers (.Mask.gbr) – Specifies the protective solder mask.
• Silkscreen layers (.Silkscreen.gbr) – Contains text and component markings.
• Paste layers (.Paste.gbr) – Used for stencil fabrication in SMD assembly.
• Drill files (.drl) – Provides drilling coordinates for vias and holes.
• Board outline (.Edge_Cuts.gbr) – Defines the shape of the PCB.
• Gerber job file (.gbrjob) – Describes the set of Gerber files used for production.

These files are ready for fabrication and can be used in PCB manufacturing.

Compliance

The Compliance section includes important regulatory and safety documentation for this product. These files ensure compliance with relevant industry standards and legal requirements.

• CE – Certification document confirming compliance with EU safety, health, and environmental requirements.
• UKCA – UKCA (UK Conformity Assessed) certification for the UK market.
• Safety Instructions – Safety guidelines and precautions in English and in German.
• Info.txt – Contains product details such as SKU, country of origin, HS tariff code, and barcode.