modulino

name	modulino
description	Arduino Modulino nodes — plug-and-play I²C sensors and actuators that connect to the Qwiic connector on the Uno Q. Read this when the user mentions a Modulino by name (Buzzer, Distance, Knob, Movement, Pixels, Thermo, Touch) or says "I have a Qwiic-connected sensor". Each Modulino has a known I²C address and a published Arduino library.

Modulino — Plug-and-play sensors for the Uno Q

Modulino is Arduino's plug-and-play sensor ecosystem. Each Modulino is a small board with a JST-SH Qwiic connector. Plug one (or a chain of several) into the Qwiic connector on the Uno Q — no breadboard, no soldering, no resistor calculations.

The Qwiic connector on the Uno Q is I²C4 on the MCU side, at 3.3 V:

Qwiic pin	MCU pin	Function
GND	GND	Ground
3V3	PWR_3P3V	3.3 V power
SDA	PD13	I²C4 data
SCL	PD12	I²C4 clock

In an Arduino sketch this is accessed via Wire.h (the default Wire instance maps to I²C4 when the Modulino library is loaded), or via the dedicated Modulino library.

The Modulino catalog

Modulino	What it does	I²C address	Library class
Modulino Buzzer	Piezo buzzer for tones	0x3C	ModulinoBuzzer
Modulino Distance	Time-of-flight distance sensor (VL53L4CD, ~4 m range)	0x29	ModulinoDistance
Modulino Knob	Rotary encoder with push button	0x76	ModulinoKnob
Modulino Movement	6-DoF IMU (accelerometer + gyro)	0x6A	ModulinoMovement
Modulino Pixels	8 RGB LEDs in a row	0x6C	ModulinoPixels
Modulino Thermo	Temperature + humidity (HS3003)	0x44	ModulinoThermo
Modulino Touch	4 capacitive touch pads	0x5A	ModulinoTouch

Canonical sketch — read a Modulino

#include <Modulino.h>

ModulinoDistance distance;

void setup() {
    Serial.begin(115200);
    Modulino.begin();        // initializes Wire on I²C4
    distance.begin();
}

void loop() {
    if (distance.available()) {
        int mm = distance.get();
        Serial.print("Distance: ");
        Serial.print(mm);
        Serial.println(" mm");
    }
    delay(100);
}

Canonical sketch — combine multiple Modulinos

You can plug several Modulinos into a Qwiic daisy-chain (each has two connectors so they pass through). The library handles multiple devices by I²C address:

#include <Modulino.h>

ModulinoBuzzer buzzer;
ModulinoDistance distance;
ModulinoPixels pixels;

void setup() {
    Modulino.begin();
    buzzer.begin();
    distance.begin();
    pixels.begin();
}

void loop() {
    int mm = 0;
    if (distance.available()) mm = distance.get();

    if (mm > 0 && mm < 100) {
        // Object close: beep + red LEDs
        buzzer.tone(1000, 100);
        pixels.set(0, ModulinoColor(255, 0, 0));
    } else {
        pixels.set(0, ModulinoColor(0, 64, 0));
    }
    pixels.show();
    delay(50);
}

Pitfalls

• Forgetting Modulino.begin(). Without it, Wire is not initialized for I²C4 and all Modulino reads return silence.
• Two Modulinos at the same address. You can't have two of the same type on the bus simultaneously (e.g., two ModulinoDistance), because both report at 0x29. Use a third-party I²C multiplexer if you need duplicates.
• Power-hungry combo. A full chain of Modulinos can draw 100+ mA from the Qwiic 3.3 V. The on-board 3.3 V rail has a budget — see uno-q-hardware/references/power.md.
• Confusing Qwiic with the Arduino Wire headers on D20/D21. Those are I²C2, a separate bus from I²C4. Modulino library targets I²C4. A regular I²C sensor on D20/D21 uses Wire directly without Modulino.begin().

See also

• uno-q-hardware/references/connectors.md — Qwiic pinout.
• bridge/SKILL.md — combine a Modulino reading with Python on the Linux side.
• sketch-patterns/SKILL.md — for general sketch scaffolding.