Custom RFID Software Development & Edge Middleware

package com.rfidsoftwares.handheld.service

import android.app.Service
import android.content.Intent
import android.os.Handler
import android.os.HandlerThread
import com.rscja.deviceapi.RFIDWithUHFUART
import com.rscja.deviceapi.entity.UHFTAGInfo
import kotlinx.coroutines.flow.MutableSharedFlow

class ChainwayRfidForegroundService : Service() {
    private var uhfReader: RFIDWithUHFUART? = null
    private var workerThread: HandlerThread? = null
    private var workerHandler: Handler? = null
    private var isInventoryRunning = false

    // Throttled reactive tag event bus (prevents Android ANRs)
    val tagStream = MutableSharedFlow<UHFTAGInfo>(replay = 0, extraBufferCapacity = 1000)

    override fun onCreate() {
        super.onCreate()
        // 1. Isolate serial UART /dev/ttyMT2 on background HandlerThread
        workerThread = HandlerThread("RFID-UART-Worker", android.os.Process.THREAD_PRIORITY_URGENT_AUDIO)
        workerThread?.start()
        workerHandler = Handler(workerThread!!.looper)

        workerHandler?.post {
            uhfReader = RFIDWithUHFUART.getInstance()
            uhfReader?.init()
            uhfReader?.setPower(30) // 30 dBm transmit power
            uhfReader?.gen2Session = 1 // Gen2 Session 1
        }
    }

    fun startContinuousInventory() {
        if (isInventoryRunning) return
        isInventoryRunning = true
        workerHandler?.post {
            uhfReader?.startInventoryTag()
            while (isInventoryRunning) {
                val tagInfo = uhfReader?.readTagFromBuffer()
                if (tagInfo != null && tagInfo.epc.isNotEmpty()) {
                    tagStream.tryEmit(tagInfo)
                }
            }
        }
    }

    override fun onDestroy() {
        isInventoryRunning = false
        // 2. CRITICAL: Free hardware UART port to prevent Linux serial lockup
        workerHandler?.post {
            uhfReader?.stopInventory()
            uhfReader?.free()
            workerThread?.quitSafely()
        }
        super.onDestroy()
    }
}