Pixlpal - Interactive AIoT Display

What is Pixlpal?

PIXLPAL is a smart AIoT desktop companion with an interactive LED display. It delivers real-time information—such as time, calendar events, weather, stocks/crypto tickers and sports updates—and offers features like AI-powered conversational assistant, HiFi audio playback from USB flash drives, and internet audio streaming.

Featuring a 128x64 RGB LED Panel (2mm pitch) and an ESP32-S3 SoC, the Pixlpal is completely hackable and extensible via it's USB-OTG interface/peripheral.

Why it was made

It all began in 2021, when a DIY digital clock built with a 64×32 RGB LED panel was discovered on the AliExpress online store.

The design looked impressive, and the idea of creating a custom version from scratch was too tempting to pass up. I already had prior experience in programming nine (9) P5 RGB 64×32 LED panels — arranged in a 3×3 grid — using the Atmel ATmega2560 microcontroller back in 2020 during a previous project.

The goal quickly shifted toward enhancing the concept by designing a custom enclosure, adding a diffuser, light and motion sensors, and an embedded battery backup system. Initial prototypes used an STM32-F1 microcontroller paired with an ESP-01 Wi-Fi module for communication, but the design later transitioned to the ESP32 Wi-Fi/Bluetooth module for its versatility and performance.

After several months of weekend work — while balancing a full-time day job — a stable prototype was completed by mid-2022: the METERBIT FRAME 1

This was a 64×32 RGB LED display powered by an ESP32 Wi-Fi/Bluetooth module, designed to be mounted on a desk, hung on a wall, or suspended from the ceiling.

The Meterbit Frame 1 looked perfect, and just when I thought I had made the coolest LED Panel Display, I found an even better display panel and Microcontroller module i.e. the 128x64 P2 RGB LED Matrix Display, and the ESP32-S3 Microcontroller/SoC.

The P2 panel offered four times the display capacity of the Meterbit Frame 1, while the ESP32-S3 added AI capabilities and USB-OTG support. This powerful combination gave birth to the PIXLPAL-M1.

Design work on the Pixlpal-M1 began in mid-2023 with the following goals in mind:1. Versatile - capable of running multiple apps for different scenarios.2. Compact - portable and suitable for desk or wall mounting.2. Power Efficient - operable via a standard 5V USB power source.3. Programmable & Extensible - through the USB-OTG interface.4. Customisable - fully controllable via a mobile app.By September 2023, a stable prototype of the Pixlpal-M1 was in hand. The design of operating system, user apps and mobile app (Android and iOS) followed in concurrency. Presently, about 15 apps ready for use on the Pixlpal and more in rapid development.

How does the Pixlpal Work?

Pixlpal fetches relevant information from the internet and displays it on the 128×64 RGB LED matrix. Using the Pixlpal mobile app, users can select and customise the app to display — such as a clock, calendar, weather updates, stock/crypto tickers, ChatGPT conversational assistant, live sports updates, or internet radio.

The Pixlpal AIoT display also includes:

• An embedded microphone for audio input.
• A 3.5 mm audio jack for audio output to external speakers.
• A multifunctional rotary encoder for manual control — allowing brightness adjustment, volume control, parameter changes, and more.

New apps and features are delivered via Over-The-Air (OTA) updates. Through the USB-OTG interface, Pixlpal can be expanded with USB peripherals such as cameras, mice, keyboards, flash drives, and speakers for added functionality.

Photos of the Pixlpal-M1