Relay APK Setup

The U300 Relay APK is an Android app that runs on a tablet at the venue. It acts as a bridge between the Chainway U300 RFID reader (on the local network) and the Parlevel cloud app.

How it works

Chainway U300 ──(LAN)──► Android Tablet (Relay APK) ──(HTTPS)──► Parlevel App

The relay:

1. Connects to the U300 reader's built-in HTTP API
2. Polls for live tag inventory on a configurable interval
3. POSTs new tag reads to Parlevel's /api/rfid/u300/ingest endpoint

Requirements

• Android tablet on the same local network as the U300 reader
• U300 reader's IP address and port (default port: 5000)
• The Parlevel ingest endpoint URL and key

Installation

1. Download the latest .apk file from the Parlevel releases page
2. Enable Install from unknown sources on the tablet (Settings → Security)
3. Install the APK
4. Open the app and enter the configuration:

Starting and stopping ingest

Once the relay is running, you control it from the Parlevel UI:

• Locations → [Location Name] → RFID tab → Start RFID — starts polling and forwarding
• Stop RFID — pauses ingest without closing the relay app

The relay app itself must remain open on the tablet. If the tablet screen locks or the app is closed, ingest stops.

APK versions

The relay API evolves with new APK builds. Key endpoint differences:

Always use the latest APK build. The Parlevel API degrades gracefully when a relay endpoint returns 404.

Network considerations

• The tablet must have a stable LAN connection to the U300 reader
• The Parlevel ingest endpoint must be reachable from the tablet (HTTPS)
• For local development, use an ngrok tunnel: ngrok http 3000 and set U300_INGEST_ENDPOINT_URL to the ngrok HTTPS URL

Troubleshooting