WIP

app/src/main/java/com/geeksville/mesh/service/SerialInterfaceService.kt

@@ -0,0 +1,79 @@
+package com.geeksville.mesh.service
+
+import com.google.android.things.pio.PeripheralManager
+import com.google.android.things.pio.UartDevice
+import com.google.android.things.pio.UartDeviceCallback
+
+class SerialInterfaceService : InterfaceService() {
+    companion object {
+        fun findPorts(): List<String> {
+            val manager = PeripheralManager.getInstance()
+            return manager.uartDeviceList
+        }
+
+        private val START1 = 0x94.toByte()
+        private val START2 = 0xc3.toByte()
+    }
+
+    private var uart: UartDevice? = null
+
+    /** The index of the next byte we are hoping to receive */
+    private var rxPtr = 0
+
+    private val callback = object : UartDeviceCallback {
+        override fun onUartDeviceDataAvailable(p0: UartDevice): Boolean {
+
+            return uart != null // keep reading until our device goes away
+        }
+
+        override fun onUartDeviceError(uart: UartDevice, error: Int) {
+            super.onUartDeviceError(uart, error)
+        }
+    }
+
+    override fun handleSendToRadio(p: ByteArray) {
+        uart?.apply {
+            val header = ByteArray(4)
+            header[0] = START1
+            header[1] = START2
+            header[2] = (p.size shr 8).toByte()
+            header[3] = (p.size and 0xff).toByte()
+            write(header, header.size)
+            write(p, p.size)
+            // flush(UartDevice.FLUSH_OUT) - I don't think we need to stall for htis
+        }
+    }
+
+    /*
+    private fun readerLoop() {
+        val scratch = ByteArray(1)
+        var ptr = 0
+        while (true) { // FIXME wait for someone to ask us to exit, and catch continuation exception
+            uart?.apply {
+                read(scratch, 1)
+                when (ptr) {
+                    0 ->
+                }
+            }
+        }
+    } */
+
+
+    override fun onCreate() {
+        super.onCreate()
+
+        val port = findPorts()[0]
+        val manager = PeripheralManager.getInstance()
+        uart = manager.openUartDevice(port)
+        uart?.apply {
+            setBaudrate(921600)
+            registerUartDeviceCallback(callback)
+        }
+    }
+
+    override fun onDestroy() {
+        uart?.close()
+        uart = null
+        super.onDestroy()
+    }
+}