Chainway C72 UHF RFID Android SDK & Guide

android {
    defaultConfig {
        // Essential: Forces 32-bit ARM runtime to match Chainway JNI drivers
        ndk {
            abiFilters.addAll(listOf("armeabi-v7a"))
        }
    }

    dependencies {
        // Link all JAR files in the libs directory
        implementation(fileTree(mapOf("dir" to "libs", "include" to listOf("*.jar"))))
        
        // Recommended: Kotlin Coroutines for asynchronous tag dispatching
        implementation("org.jetbrains.kotlinx:kotlinx-coroutines-android:1.8.0")
    }
}

package com.rfidsoftwares.demo.chainway

import android.os.Bundle
import android.os.Handler
import android.os.Looper
import android.util.Log
import android.view.KeyEvent
import androidx.appcompat.app.AppCompatActivity
import com.rscja.deviceapi.RFIDWithUHFUART
import com.rscja.deviceapi.entity.UHFTAGInfo

class ChainwayInventoryActivity : AppCompatActivity() {

    private var mReader: RFIDWithUHFUART? = null
    private var isInventoryRunning = false
    private val mainHandler = Handler(Looper.getMainLooper())

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        initHardwareReader()
    }

    private fun initHardwareReader() {
        // ALWAYS initialize hardware on a worker thread to prevent UI freezing
        Thread {
            try {
                mReader = RFIDWithUHFUART.getInstance()
                val success = mReader?.init() ?: false
                if (success) {
                    Log.i("Chainway", "UHF Reader powered on successfully.")
                    // Set RF transmission power (5 to 30 dBm; 30 = Max distance)
                    mReader?.setPower(30)
                    // Set Indian WPC Frequency Hopping (865 - 867 MHz)
                    mReader?.setFrequencyMode(3)
                } else {
                    Log.e("Chainway", "Failed to power on UART serial port /dev/ttyMT2")
                }
            } catch (e: Exception) {
                Log.e("Chainway", "Hardware init exception", e)
            }
        }.start()
    }

    fun startInventory() {
        if (isInventoryRunning || mReader == null) return
        val started = mReader?.startInventoryTag() ?: false
        if (started) {
            isInventoryRunning = true
            startReadThread()
        }
    }

    fun stopInventory() {
        if (!isInventoryRunning) return
        mReader?.stopInventory()
        isInventoryRunning = false
    }

    private fun startReadThread() {
        Thread {
            while (isInventoryRunning && mReader != null) {
                // Read from internal hardware circular buffer
                val tagInfo: UHFTAGInfo? = mReader?.readTagFromBuffer()
                if (tagInfo != null) {
                    val epc = tagInfo.epc
                    val rssi = tagInfo.rssi
                    mainHandler.post {
                        onTagScanned(epc, rssi)
                    }
                } else {
                    Thread.sleep(10) // Yield CPU to avoid thread starvation
                }
            }
        }.start()
    }

    private fun onTagScanned(epc: String, rssi: String?) {
        Log.d("Chainway", "Tag Read: EPC=$epc | RSSI=$rssi dBm")
        // Route to SQLite outbox, ViewModel StateFlow, or ERP sync
    }

    // Intercept physical pistol grip trigger keycode
    override fun onKeyDown(keyCode: Int, event: KeyEvent?): Boolean {
        if (keyCode == 139 || keyCode == KeyEvent.KEYCODE_F4) {
            if (event?.repeatCount == 0 && !isInventoryRunning) {
                startInventory()
                return true
            }
        }
        return super.onKeyDown(keyCode, event)
    }

    override fun onKeyUp(keyCode: Int, event: KeyEvent?): Boolean {
        if (keyCode == 139 || keyCode == KeyEvent.KEYCODE_F4) {
            stopInventory()
            return true
        }
        return super.onKeyUp(keyCode, event)
    }

    override fun onDestroy() {
        super.onDestroy()
        stopInventory()
        // CRUCIAL: Release UART serial port and cut RF module battery power
        mReader?.free()
        mReader = null
    }
}