diff --git a/libs/core/control.cpp b/libs/core/control.cpp
index c291a452..9f0042d5 100644
--- a/libs/core/control.cpp
+++ b/libs/core/control.cpp
@@ -27,4 +27,13 @@ int allocateNotifyEvent() {
 void dmesg(String s) {
     DMESG("# %s", s->data);
 }
+
 }
+
+namespace serial {
+    /** Send DMESG debug buffer over serial. */
+    //%
+    void writeDmesg() {
+        pxt::dumpDmesg();
+    }
+}
\ No newline at end of file
diff --git a/libs/core/core.ts b/libs/core/core.ts
index 4f896f65..b2f78820 100644
--- a/libs/core/core.ts
+++ b/libs/core/core.ts
@@ -27,6 +27,7 @@ const enum LMS {
     DEVICE_TYPE_MINITACHO = 8,
     DEVICE_TYPE_NEWTACHO = 9,
     DEVICE_TYPE_TOUCH = 16,
+    DEVICE_TYPE_IR = 33,
     DEVICE_TYPE_THIRD_PARTY_START = 50,
     DEVICE_TYPE_THIRD_PARTY_END = 99,
     DEVICE_TYPE_IIC_UNKNOWN = 100,
diff --git a/libs/core/dmesg.txt b/libs/core/dmesg.txt
new file mode 100644
index 00000000..319d31f8
--- /dev/null
+++ b/libs/core/dmesg.txt
@@ -0,0 +1,6 @@
+[       1] runtime starting...
+[      53] runtime started [V0.60]
+[      55] mmap /dev/lms_analog len=5172 off=0
+[      56] mmap /dev/lms_uart len=42744 off=0
+[      64] Error: 7 [0]
+[      64] PANIC 42
diff --git a/libs/core/input.ts b/libs/core/input.ts
index 59d40fd3..7c3475c6 100644
--- a/libs/core/input.ts
+++ b/libs/core/input.ts
@@ -80,16 +80,19 @@ namespace input.internal {
             info.connType = newConn
             info.devType = LMS.DEVICE_TYPE_NONE
             if (newConn == LMS.CONN_INPUT_UART) {
+                control.dmesg(`new UART connection at ${info.port}`)
                 setUartMode(info.port, 0)
                 let uinfo = readUartInfo(info.port, 0)
                 info.devType = uinfo[TypesOff.Type]
+                control.dmesg(`UART type ${info.devType}`)
             } else if (newConn == LMS.CONN_INPUT_DUMB) {
+                control.dmesg(`new DUMB connection at ${info.port}`)
                 // TODO? for now assume touch
                 info.devType = LMS.DEVICE_TYPE_TOUCH
-            } else if (newConn == LMS.CONN_NONE) {
-                // OK
+            } else if (newConn == LMS.CONN_NONE || newConn == 0) {
+                control.dmesg(`disconnect at ${info.port}`)
             } else {
-                // ???
+                control.dmesg(`unknown connection type: ${newConn} at ${info.port}`)
             }
         }
 
@@ -106,12 +109,16 @@ namespace input.internal {
 
         for (let info of autos) {
             if (!info.sensor && info.devType != LMS.DEVICE_TYPE_NONE) {
+                let found = false
                 for (let s of autoSensors) {
                     if (s.getPort() == 0 && s._deviceType() == info.devType) {
                         s._setPort(info.port + 1)
+                        found = true
                         break
                     }
                 }
+                if (!found)
+                    control.dmesg(`sensor not found for type=${info.devType} at ${info.port}`)
             }
         }
     }
@@ -133,6 +140,8 @@ namespace input.internal {
         _setPort(port: number, manual = false) {
             port = Math.clamp(0, 4, port | 0) - 1;
             if (port == this.port) return
+            this.port = port
+            control.dmesg(`sensor set port ${port} on devtype=${this._deviceType()}`)
             for (let i = 0; i < sensors.length; ++i) {
                 if (i != this.port && sensors[i].sensor == this) {
                     sensors[i] = null
@@ -190,27 +199,33 @@ namespace input.internal {
 
     export class UartSensor extends Sensor {
         protected mode: number
+        protected realmode: number
 
         constructor() {
             super()
+            this.mode = 0
+            this.realmode = -1
         }
 
         protected _portUpdated() {
-            this.mode = -1
+            this.realmode = -1
             if (this.port > 0) {
                 if (this.isManual()) {
                     uartReset(this.port)
                 } else {
-                    this.mode = 0
+                    this.realmode = 0
                 }
+                this._setMode(this.mode)
             }
         }
 
         protected _setMode(m: number) {
-            if (this.port < 0) return
+            //control.dmesg(`_setMode p=${this.port} m: ${this.realmode} -> ${m}`)
             let v = m | 0
-            if (v != this.mode) {
-                this.mode = v
+            this.mode = v
+            if (this.port < 0) return
+            if (this.realmode != this.mode) {
+                this.realmode = v
                 setUartMode(this.port, v)
             }
         }
@@ -226,6 +241,7 @@ namespace input.internal {
 
     function uartReset(port: number) {
         if (port < 0) return
+        control.dmesg(`UART reset at ${port}`)
         devcon.setNumber(NumberFormat.Int8LE, DevConOff.Connection + port, LMS.CONN_NONE)
         devcon.setNumber(NumberFormat.Int8LE, DevConOff.Type + port, 0)
         devcon.setNumber(NumberFormat.Int8LE, DevConOff.Mode + port, 0)
@@ -272,6 +288,7 @@ namespace input.internal {
         const UART_PORT_CHANGED = 1
         while (true) {
             if (port < 0) return
+            control.dmesg(`UART set mode to ${mode} at ${port}`)
             devcon.setNumber(NumberFormat.Int8LE, DevConOff.Connection + port, LMS.CONN_INPUT_UART)
             devcon.setNumber(NumberFormat.Int8LE, DevConOff.Type + port, 33)
             devcon.setNumber(NumberFormat.Int8LE, DevConOff.Mode + port, mode)
diff --git a/libs/core/ir.ts b/libs/core/ir.ts
index 1ff39308..b9878e93 100644
--- a/libs/core/ir.ts
+++ b/libs/core/ir.ts
@@ -77,6 +77,10 @@ namespace input {
             }
         }
 
+        _deviceType() {
+            return LMS.DEVICE_TYPE_IR
+        }
+
         setRemoteChannel(c: IrRemoteChannel) {
             c = Math.clamp(0, 3, c | 0)
             this.channel = c
diff --git a/libs/core/linux.cpp b/libs/core/linux.cpp
index a7ee17e1..f1af78d2 100644
--- a/libs/core/linux.cpp
+++ b/libs/core/linux.cpp
@@ -52,6 +52,7 @@ static struct Thread *allThreads;
 static struct Event *eventHead, *eventTail;
 static int usbFD;
 static int dmesgPtr;
+static int dmesgSerialPtr;
 static char dmesgBuf[4096];
 
 struct Event {
@@ -366,9 +367,11 @@ uint32_t afterProgramPage() {
     return 0;
 }
 void dumpDmesg() {
-    sendSerial("\nDMESG:\n", 8);
-    sendSerial(dmesgBuf, dmesgPtr);
-    sendSerial("\n\n", 2);
+    auto len = dmesgPtr - dmesgSerialPtr;
+    if (len == 0)
+        return;
+    sendSerial(dmesgBuf + dmesgSerialPtr, len);
+    dmesgSerialPtr = dmesgPtr;
 }
 
 int lmsPid;
@@ -458,6 +461,7 @@ void dmesgRaw(const char *buf, uint32_t len) {
         return;
     if (dmesgPtr + len > sizeof(dmesgBuf)) {
         dmesgPtr = 0;
+        dmesgSerialPtr = 0;
     }
     memcpy(dmesgBuf + dmesgPtr, buf, len);
     dmesgPtr += len;
diff --git a/libs/core/shims.d.ts b/libs/core/shims.d.ts
index d6da5179..00e0e887 100644
--- a/libs/core/shims.d.ts
+++ b/libs/core/shims.d.ts
@@ -56,6 +56,12 @@ declare namespace control {
     //% shim=control::dmesg
     function dmesg(s: string): void;
 }
+declare namespace serial {
+
+    /** Send DMESG debug buffer over serial. */
+    //% shim=serial::writeDmesg
+    function writeDmesg(): void;
+}
 declare namespace input {
 
     /**
diff --git a/libs/core/test.ts b/libs/core/test.ts
index a96989d8..722baf3c 100644
--- a/libs/core/test.ts
+++ b/libs/core/test.ts
@@ -26,12 +26,27 @@ input.buttonUp.onEvent(ButtonEvent.Click, () => {
     screen.scroll(10)
 })
 
-for (let i = 0; i < 3; ++i) {
-    loops.forever(() => {
-        let r = Math.randomRange(0, 100)
-        serial.writeValue("R", r)
-        //screen.drawText(10, 10, `R=${r}`)
-        loops.pause(1000)
-    })
-    loops.pause(300)
-}
+
+let num = 0
+
+input.touch.button.onEvent(ButtonEvent.Click, () => {
+    screen.drawText(10, 60, "Click!  " + num)
+    num++
+})
+
+input.ir.getRemoteCommand()
+
+input.ir.button(IrRemoteButton.TopLeft).onEvent(ButtonEvent.Down, () => {
+    screen.drawText(10, 60, "TOPLEFT " + num)
+    num++
+})
+
+input.ir.button(IrRemoteButton.TopRight).onEvent(ButtonEvent.Down, () => {
+    screen.drawText(10, 60, "TOPRIGH " + num)
+    num++
+})
+
+loops.forever(() => {
+    serial.writeDmesg()
+    loops.pause(400)
+})
diff --git a/libs/core/touch.ts b/libs/core/touch.ts
index dfdf1865..172bb455 100644
--- a/libs/core/touch.ts
+++ b/libs/core/touch.ts
@@ -14,6 +14,10 @@ namespace input {
         _update(prev: number, curr: number) {
             this.button.update(curr > 0)
         }
+
+        _deviceType() {
+            return LMS.DEVICE_TYPE_TOUCH
+        }
     }
 
     //% whenUsed