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EP-0257

Level-Shift Shield for Arduino UNO Q

SKU: EP-0257 EP-0257-01.jpg

Description

The Level-Shift Shield for Arduino UNO Q is a bidirectional level translation shield purpose-built for the Arduino UNO Q platform. Featuring a standard Shield plug-and-play form factor, it stacks directly onto the mainboard. The core employs the Texas Instruments (TI) TXS0108EPWR auto-direction sensing bidirectional voltage-level translator. This shield is intended for bidirectional level translation between the Arduino UNO Q's 3.3V IO and 5V devices/modules, suitable for interfacing with 5V sensors, communication modules (such as I2C, SPI, and UART devices), and other GPIO peripherals, helping reduce risks of communication failures and device damage caused by logic level mismatches under recommended conditions. Special Design: The board features a rectangular central cutout positioned above the Arduino UNO Q onboard LED Matrix, preserving visibility of LED status indicators during Shield operation.

IMPORTANT NOTE: Do not connect 5V signal lines to VIN, AREF, IOREF, BOOT, or GND — these pins are direct pass-through to the Arduino UNO Q (Green color headers). Incorrect wiring may permanently damage or destroy the Arduino UNO Q. Please exercise extreme caution. EP-0257-04.jpg

Features

  • Standard Arduino UNO Q Shield form factor, stacks directly with zero additional wiring
  • Rectangular central cutout preserves visibility of Arduino UNO Q mainboard LED Matrix
  • 8-bit parallel conversion with fully independent per-channel operation
  • Supports Partial Power-Down mode with automatic high-impedance I/O state
  • Color-coded headers (red/yellow/blue/black/white) for quick identification and wiring
EP-0257-09.jpg ===Electrical Specifications===
Parameterl Value
Product Name Level-Shift Shield for Arduino UNO Q
Version V1.1 (2026/3/26)
Core IC Texas Instruments TXS0108EPWR (TSSOP-20)
ESD Protection IEC 61000-4-2 ESD
Operating Temperature -40 °C to +85 °C

Level-Shift Shield Pin Conversion Status Summary

Pin / Area Color Conversion Status Direction Description
D0 (RX) Blue ✅ Converted Bidirectional 3.3V ↔ 5V auto-direction
D1 (TX) Blue ✅ Converted Bidirectional 3.3V ↔ 5V auto-direction
D2–D9 Blue ✅ Converted Bidirectional 3.3V ↔ 5V digital I/O
D10 (SS) Blue ✅ Converted Bidirectional SPI Chip Select
D11 (MOSI) Blue ✅ Converted Bidirectional SPI Master Out Slave In
D12 (MISO) Blue ✅ Converted Bidirectional SPI Master In Slave Out
D13 (SCK) Blue ✅ Converted Bidirectional SPI Clock
D20–D21 Blue ✅ Converted Bidirectional 3.3V ↔ 5V digital I/O
A0 White ✅ Converted Bidirectional 3.3V ↔ 5V digital I/O
A1 White ✅ Converted Bidirectional 3.3V ↔ 5V digital I/O
A2 White ✅ Converted Bidirectional 3.3V ↔ 5V digital I/O
A3 White ✅ Converted Bidirectional 3.3V ↔ 5V digital I/O
A4 (SDA) White ✅ Converted Bidirectional I2C Data, 3.3V ↔ 5V
A5 (SCL) White ✅ Converted Bidirectional I2C Clock, 3.3V ↔ 5V
VIN Green ❌ Not Converted (Pass-through) — Arduino UNO Q external voltage input pass-through
AREF Green ❌ Not Converted (Pass-through) — Voltage reference pass-through
RESET Green ❌ Not Converted (Pass-through) — System reset pass-through
IOREF Green ❌ Not Converted (Pass-through) — I/O reference voltage pass-through
BOOT Green ❌ Not Converted (Pass-through) — Boot mode select pass-through
GND (System Area) Black ❌ Not Converted (Pass-through) — System ground pass-through
5V (Power Rail) Red ❌ Not Converted (Power Output) — Arduino UNO Q regulated 5V output for external use
3V3 (Power Rail) Yellow ❌ Not Converted (Power Output) — Arduino UNO Q regulated 3.3V output for external use
GND (Left Side / Power Rail) Black ❌ Not Converted (Power Ground) — Common ground reference

Interface Layout

  • Pinout:
EP-0257-10.jpg Based on the physical board design, the interface layout is organized as follows:

Left Side — Digital Level-Shift Area

Pin Label Color Function
GND Black Ground reference
3V3 Yellow 3.3V power output
5V Red 5V power output
D0–D13/D20-D21 Blue Digital I/O level-shifted channels (Arduino UNO Q D0–D13/D20-D21 mapped to 3.3V-compatible signals) 
NOTE: Three TXS0108EPWR devices provide level translation for all digital pins D0 through D13, D20 and D21, with color-coded headers for quick identification and wiring.

Right Side — System & Analog Area

  • Upper Section (Green/Black Headers)
Pin Label Color Function
VIN Green Arduino UNO Q external voltage input (pass-through)
AREF Green Voltage reference (pass-through)
RESET Green System reset (pass-through)
IOREF Green I/O reference voltage (pass-through)
BOOT Green Boot mode select (pass-through)
GND Black Ground reference (pass-through) 
NOTE: System control pins are routed through via pass-through headers, maintaining full compatibility with Arduino UNO Q standard pinout.
  • Middle Section (Power Rails)
Pin Label Color Voltage Current Capability
5V Red 5.0V Sourced from Arduino UNO Q regulated 5V rail
3V3 Yellow 3.3V Sourced from Arduino UNO Q onboard 3.3V regulator 
Note: Dedicated power rail headers provide easy access for external 5V peripherals and modules.
  • Lower Section (White Headers)

NOTE：Using A0-A5 as Digital Pins

Pin Label Color Function
A0 White Using A0 as Digital Pin
A1 White Using A1 as Digital Pin
A2 White Using A2 as Digital Pin
A3 White Using A3 as Digital Pin
A4(SDA) White Using A4 as Digital Pin
A5(SCL) White Using A5 as Digital Pin
  • Central Cutout
Feature Description
Rectangular opening Strategic cutout positioned directly above the Arduino UNO Q onboard LED Matrix
Purpose Preserves full visual access to LED Matrix status indicators during Shield operation
Benefit Eliminates need to remove Shield for visual debugging or status monitoring

Color Code Reference

Color Category
Black Ground (GND)
Yellow 3.3V power / low-voltage side reference
Red 5V power / high-voltage side reference
Blue Digital I/O signals
Green System control pass-through
White Analog input signals
EP-0257-11.jpg

Installation Guide

Step 1: Pre-Installation Check

Before installing the Level-Shift Shield, verify the following:

  • Ensure the Arduino UNO Q mainboard is powered off and disconnected from USB or external power.
  • Confirm all pins on the Shield are straight and properly aligned—no bent pins.
  • Check that the central cutout orientation matches the LED Matrix position on the Arduino UNO Q.

Step 2: Physical Installation

  • Align the Shield's female headers with the male pin headers on the Arduino UNO Q.
  • The USB connector side of the Shield faces the same direction as the Arduino UNO Q USB port.
  • Gently press the Shield down evenly until all pins are fully seated and the boards are parallel.
  • The central cutout should sit directly above the LED Matrix with no obstruction.
EP-0257-08.jpg ----

I2C Bus Connection

The Arduino UNO Q uses A4 (SDA) and A5 (SCL) on the Shield:

Signal Shield Pin Connect To
SDA A4 (white) SDA of 5V I2C sensor/module
SCL A5 (white) SCL of 5V I2C sensor/module
GND GND (black) GND of sensor/module
5V 5V(red) VCC of sensor/module
EP-0257-06.jpg Example: Connect a LCD1602 Display Module:
  • LCD1602 VCC → Shield 5V (Red)
  • LCD1602 GND → Shield GND (black)
  • LCD1602 SDA → Shield A4 (white)
  • LCD1602 SCL → Shield A5 (white)

Use the standard Arduino Wire.h library. The Shield handles all level translation automatically.

SPI Bus Connection

SPI pins D10–D13:

Signal Shield Pin Connect To
SS D10 (blue) CS of 5V SPI device
MOSI D11 (blue) DIN/SDI of 5V SPI device
MISO D12 (blue) DOUT/SDO of 5V SPI device
SCK D13 (blue) CLK of 5V SPI device
EP-0257-05.jpg Example: Connect a Max7219 LED matrix module:
  • LED Matrix VCC → Shield 5V (red)
  • LED Matrix GND → Shield GND (black)
  • LED Matrix CS → Shield D10 (blue)
  • LED Matrix DI → Shield D11 (blue)
  • LED Matrix DO → Shield D12 (blue)
  • LED Matrix CLK → Shield D13 (blue)

Use the standard Arduino SPI.h library to communicate with SPI peripherals.

UART Serial Connection

Digital pins D0 (RX) and D1 (TX):

Signal Shield Pin Connect To
RX D0 (blue) TX of 5V UART module
TX D1 (blue) RX of 5V UART module

Example: If you want to connect to the shield via the serial port of an Arduino UNO board, you can simply follow the connection method shown in the figure above without worrying about the voltage level:

  • Arduino UNO VCC → Shield 5 (red)
  • Arduino UNO GND → Shield GND (black)
  • Arduino UNO TX → Shield D0 (blue)
  • Arduino UNO RX → Shield D1 (blue)

Use Serial.begin(115200) or higher baud rates. The Shield automatically translates both directions.

Power Output Usage

The power rail headers supply regulated voltage for external peripherals:

Rail Color Voltage Typical Use
5V Red 5.0V 5V sensors, relay modules, servos
3V3 Yellow 3.3V 3.3V sensors, wireless modules, displays
GND Black 0V Common ground reference 
NOTE: Current Budget: Do not exceed the Arduino UNO Q onboard regulator current limits (typically 150 mA for 3.3V rail, 500 mA total via USB). For high-current loads, use external power with common ground.

LED Matrix Monitoring

With the Shield installed:

  • The central cutout provides unobstructed view of the Arduino UNO Q LED Matrix.
  • Use the LED Matrix for runtime status indication, error codes, or animation feedback.
  • No disassembly required for visual debugging.

Disassembly

  • 1. Power off and disconnect all cables from the Arduino UNO Q.
  • 2. Grasp the edges of the Level-Shift Shield firmly.
  • 3. Pull straight up evenly to avoid bending pins.
  • 4. Store in anti-static packaging if not in immediate use.

Gallery

  • Product Outlook
EP-0257-02.jpg \* Product dimension information EP-0257-03.jpg

Package Includes

  • 1 x Level-Shift Shield for Arduino UNO Q Pack