# Olimex ESP32-P4-PC gets Arduino LTE demo and ESP-IDF hardware test suite

> **Key takeaway:** Olimex released two open-source demos for its ESP32-P4-PC board: an Arduino sketch for 4G LTE modem connectivity and an ESP-IDF application that interactively tests all major onboard peripherals.

**Published:** 2026-10-20T10:45:13+00:00 
**Source:** Olimex Blog 
**Category:** open-hardware 
**Canonical URL:** https://fosswire.org/news/olimex-esp32-p4-pc-gets-arduino-lte-demo-and-esp-idf-hardwar.html 

## Summary
Olimex added two software demos to the ESP32-P4-PC GitHub repository. The first is an Arduino demo connecting the board to Olimex's USB-LTE4G-EU LTE Cat 1 bis modem over UART, requiring the new UEXT-LVL-SHIFT board to bridge 1.8 V and 3.3 V logic levels. The second is an ESP-IDF application that tests HDMI output, microSD, USB host, audio, and Ethernet without needing a PC or test fixture, producing a PASS/WARN/FAIL/SKIP summary.

## What the two demos cover
- **LTE demo**: Arduino-based, communicates with Quectel EG800K-EU modem via UART at 1.8 V; probes modem info, SIM status, signal quality; supports interactive AT commands through Serial Monitor
- **Level shifter required**: UEXT-LVL-SHIFT board (4.95 EUR) bridges 1.8 V modem logic to 3.3 V UEXT; handles UART, SPI, I2C up to 420 Mbps
- **Hardware test demo**: ESP-IDF v5.5.5, outputs 1280×720 @ 60 Hz via LT8912B DSI-to-HDMI bridge
- **Five automated tests**: microSD 4-bit SDMMC at 20 MHz, USB host on any of four ports, ES8311 audio loopback, IP101 Ethernet with DHCP/ping
- **No PC software needed**: BOOT button controls test flow; results display on HDMI and serial console

## Why it matters
The ESP-IDF hardware test suite lowers the barrier for verifying board functionality during bring-up or manufacturing, while the LTE demo extends the ESP32-P4-PC into cellular IoT applications where Wi-Fi and Ethernet are unavailable.