diff --git a/libs/color-sensor/color.ts b/libs/color-sensor/color.ts
index 007c7064..34fd3f82 100644
--- a/libs/color-sensor/color.ts
+++ b/libs/color-sensor/color.ts
@@ -81,7 +81,7 @@ namespace sensors {
                 else maxModeRange = 100; // ReflectedLightIntensity or AmbientLightIntensity
                 this._setMode(m); // Change mode
                 pause(MODE_SWITCH_DELAY);
-                pauseUntil(() => (this.getStatus() == 8 && (this.mode == ColorSensorMode.RgbRaw ? this._queryArr()[0] : this._query()) <= maxModeRange)); // Pause until mode change
+                pauseUntil(() => (this.getStatus() == 8 && this._query()[0] <= maxModeRange)); // Pause until mode change
             } else {
                 this._setMode(m);
             }
@@ -98,47 +98,33 @@ namespace sensors {
             if (this.mode == ColorSensorMode.Color
                 || this.mode == ColorSensorMode.AmbientLightIntensity
                 || this.mode == ColorSensorMode.ReflectedLightIntensity)
-                return this.getNumber(NumberFormat.UInt8LE, 0)
+                return [this.getNumber(NumberFormat.UInt8LE, 0)];
             else if (this.mode == ColorSensorMode.RefRaw)
-                return this.getNumber(NumberFormat.UInt16LE, 0)
-            return 0
-        }
-
-        _queryArr(): number[] {
-            if (this.mode == ColorSensorMode.RgbRaw) {
+                return [this.getNumber(NumberFormat.UInt16LE, 0)];
+            else if (this.mode == ColorSensorMode.RgbRaw) {
                 return [this.getNumber(NumberFormat.UInt16LE, 0), this.getNumber(NumberFormat.UInt16LE, 2), this.getNumber(NumberFormat.UInt16LE, 4)];
             }
-            return [0, 0, 0];
+            return [0];
         }
 
-        _info(): string {
+        _info() {
             switch (this.mode) {
                 case ColorSensorMode.Color:
-                    return ["none",
+                    return [["none",
                         "black",
                         "blue",
                         "green",
                         "yellow",
                         "red",
                         "white",
-                        "brown"][this._query()];
+                        "brown"][this._query()[0]]];
                 case ColorSensorMode.AmbientLightIntensity:
                 case ColorSensorMode.ReflectedLightIntensity:
-                    return `${this._query()}%`;
-                case ColorSensorMode.RgbRaw:
-                    return "array";
-                default:
-                    return this._query().toString();
-            }
-        }
-
-        _infoArr(): string[] {
-            switch (this.mode) {
+                    return [`${this._query()}%`];
                 case ColorSensorMode.RgbRaw:
-                    const queryArr = this._queryArr().map(number => number.toString());
-                    return queryArr;
+                    return this._query().map(number => number.toString());
                 default:
-                    return ["0", "0", "0"];
+                    return [this._query()[0].toString()];
             }
         }
 
diff --git a/libs/core/buttons.ts b/libs/core/buttons.ts
index 3033d3c0..34c6bca2 100644
--- a/libs/core/buttons.ts
+++ b/libs/core/buttons.ts
@@ -1,30 +1,3 @@
-
-/**
- * Patterns for lights under the buttons.
- */
-const enum StatusLight {
-    //% block=off enumval=0
-    Off = 0,
-    //% block=green enumval=1
-    Green = 1,
-    //% block=red enumval=2
-    Red = 2,
-    //% block=orange enumval=3
-    Orange = 3,
-    //% block="green flash" enumval=4
-    GreenFlash = 4,
-    //% block="red flash" enumval=5
-    RedFlash = 5,
-    //% block="orange flash" enumval=6
-    OrangeFlash = 6,
-    //% block="green pulse" enumval=7
-    GreenPulse = 7,
-    //% block="red pulse" enumval=8
-    RedPulse = 8,
-    //% block="orange pulse" enumval=9
-    OrangePulse = 9,
-}
-
 /**
  * User interaction on buttons
  */
@@ -246,34 +219,4 @@ namespace control {
         }
         return r
     }
-}
-
-namespace brick {
-    // the brick starts with the red color
-    let currPattern: StatusLight = StatusLight.Off;
-
-    /**
-     * Gets the current light pattern.
-     */
-    //% weight=99 group="Buttons"
-    //% help=brick/status-light
-    export function statusLight() {
-        return currPattern;
-    }
-
-    /**
-     * Set lights.
-     * @param pattern the lights pattern to use. eg: StatusLight.Orange
-     */
-    //% blockId=setLights block="set status light to %pattern"
-    //% weight=100 group="Buttons"
-    //% help=brick/set-status-light
-    export function setStatusLight(pattern: StatusLight): void {
-        if (currPattern === pattern)
-            return
-        currPattern = pattern;
-        const cmd = output.createBuffer(2)
-        cmd[0] = pattern + 48
-        brick.internal.getBtnsMM().write(cmd)
-    }
-}
+}
\ No newline at end of file
diff --git a/libs/core/indicator.ts b/libs/core/indicator.ts
new file mode 100644
index 00000000..c327a70b
--- /dev/null
+++ b/libs/core/indicator.ts
@@ -0,0 +1,55 @@
+/**
+ * Patterns for lights under the buttons.
+ */
+const enum StatusLight {
+    //% block=off enumval=0
+    Off = 0,
+    //% block=green enumval=1
+    Green = 1,
+    //% block=red enumval=2
+    Red = 2,
+    //% block=orange enumval=3
+    Orange = 3,
+    //% block="green flash" enumval=4
+    GreenFlash = 4,
+    //% block="red flash" enumval=5
+    RedFlash = 5,
+    //% block="orange flash" enumval=6
+    OrangeFlash = 6,
+    //% block="green pulse" enumval=7
+    GreenPulse = 7,
+    //% block="red pulse" enumval=8
+    RedPulse = 8,
+    //% block="orange pulse" enumval=9
+    OrangePulse = 9,
+}
+
+namespace brick {
+    // the brick starts with the red color
+    let currPattern: StatusLight = StatusLight.Off;
+
+    /**
+     * Gets the current light pattern.
+     */
+    //% weight=99 group="Indicator"
+    //% help=brick/status-light
+    export function statusLight() {
+        return currPattern;
+    }
+
+    /**
+     * Set lights.
+     * @param pattern the lights pattern to use. eg: StatusLight.Orange
+     */
+    //% blockId=setLights block="set status light to %pattern"
+    //% weight=100 group="Indicator"
+    //% help=brick/set-status-light
+    export function setStatusLight(pattern: StatusLight): void {
+        if (currPattern === pattern)
+            return
+        currPattern = pattern;
+        const cmd = output.createBuffer(2)
+        cmd[0] = pattern + 48
+        brick.internal.getBtnsMM().write(cmd)
+    }
+}
diff --git a/libs/core/input.ts b/libs/core/input.ts
index 9e1c5fff..a56cfde7 100644
--- a/libs/core/input.ts
+++ b/libs/core/input.ts
@@ -1,4 +1,8 @@
 namespace sensors.internal {
+
+    const UART_PORT_CHANGED = 1;
+    const UART_DATA_READY = 8;
+
     export class Poller {
         private query: () => number;
         private update: (previous: number, current: number) => void;
@@ -7,7 +11,7 @@ namespace sensors.internal {
         private previousValue: number;
         private currentValue: number;
         private lastQuery: number; // track down the last time we did a query/update cycle
-        private lastPause: number;  // track down the last time we pause in the sensor polling loop
+        private lastPause: number; // track down the last time we pause in the sensor polling loop
 
         constructor(interval: number, query: () => number, update: (previous: number, current: number) => void) {
             this.interval = interval | 0;
@@ -35,6 +39,7 @@ namespace sensors.internal {
 
         private poll() {
             control.runInBackground(() => {
+                pause(this.interval);
                 this.lastQuery = this.lastPause = control.millis();
                 this.previousValue = this.currentValue = this.query();
                 this.update(this.previousValue, this.currentValue);
@@ -55,12 +60,12 @@ namespace sensors.internal {
         return s
     }
 
-    let analogMM: MMap
-    let uartMM: MMap
-    let IICMM: MMap
-    let powerMM: MMap
-    let devcon: Buffer
-    let devPoller: Poller
+    let analogMM: MMap;
+    let uartMM: MMap;
+    let IICMM: MMap;
+    let powerMM: MMap;
+    let devcon: Buffer;
+    let devPoller: Poller;
     let sensorInfos: SensorInfo[];
 
     let batteryInfo: {
@@ -94,7 +99,7 @@ namespace sensors.internal {
         }
 
         private query() {
-            if (this.sensor) return this.sensor._query();
+            if (this.sensor) return this.sensor._query()[0];
             return 0;
         }
 
@@ -120,10 +125,11 @@ namespace sensors.internal {
 
         powerMM = control.mmap("/dev/lms_power", 2, 0)
 
-        devPoller = new Poller(250, () => { return hashDevices(); },
+        devPoller = new Poller(900, () => { return hashDevices(); },
             (prev, curr) => {
                 detectDevices();
-            });
+            }
+        );
     }
 
     export function getActiveSensors(): Sensor[] {
@@ -131,25 +137,6 @@ namespace sensors.internal {
         return sensorInfos.filter(si => si.sensor && si.sensor.isActive()).map(si => si.sensor);
     }
 
-    function readUartInfo(port: number, mode: number) {
-        let buf = output.createBuffer(UartCtlOff.Size)
-        buf[UartCtlOff.Port] = port
-        buf[UartCtlOff.Mode] = mode
-        uartMM.ioctl(IO.UART_READ_MODE_INFO, buf)
-        return buf
-        //let info = `t:${buf[TypesOff.Type]} c:${buf[TypesOff.Connection]} m:${buf[TypesOff.Mode]} n:${buf.slice(0, 12).toHex()}`
-        //serial.writeLine("UART " + port + " / " + mode + " - " + info)
-    }
-
-    export function readIICID(port: number) {
-        const buf = output.createBuffer(IICStr.Size)
-        buf[IICStr.Port] = port
-        IICMM.ioctl(IO.IIC_READ_TYPE_INFO, buf)
-        const manufacturer = bufferToString(buf.slice(IICStr.Manufacturer, 8))
-        const sensorType = bufferToString(buf.slice(IICStr.SensorType, 8))
-        return manufacturer + sensorType;
-    }
-
     const ADC_REF = 5000                  //!< [mV]  maximal value on ADC
     const ADC_RES = 4095                  //!< [CNT] maximal count on ADC
     // see c_ui.c
@@ -220,42 +207,7 @@ namespace sensors.internal {
         const CinCnt = batteryInfo.CinCnt;
         const CoutCnt = batteryInfo.CoutCnt;
         const VinCnt = batteryInfo.VinCnt;
-        /*
-void      cUiUpdatePower(void)
-{
-#ifndef Linux_X86
-  DATAF   CinV;
-  DATAF   CoutV;
-
-  if ((UiInstance.Hw == FINAL) || (UiInstance.Hw == FINALB))
-  {
-    CinV                =  CNT_V(UiInstance.CinCnt) / AMP_CIN;
-    UiInstance.Vbatt    =  (CNT_V(UiInstance.VinCnt) / AMP_VIN) + CinV + VCE;
-
-    UiInstance.Ibatt    =  CinV / SHUNT_IN;
-    CoutV               =  CNT_V(UiInstance.CoutCnt) / AMP_COUT;
-    UiInstance.Imotor   =  CoutV / SHUNT_OUT;
-
-  }
-  else
-  {
-    CinV                =  CNT_V(UiInstance.CinCnt) / EP2_AMP_CIN;
-    UiInstance.Vbatt    =  (CNT_V(UiInstance.VinCnt) / AMP_VIN) + CinV + VCE;
-
-    UiInstance.Ibatt    =  CinV / EP2_SHUNT_IN;
-    UiInstance.Imotor   =  0;
-
-  }
-
-#endif
-#ifdef DEBUG_TEMP_SHUTDOWN
-
-  UiInstance.Vbatt  =  7.0;
-  UiInstance.Ibatt  =  5.0;
-
-#endif
-}        
-        */
+
         const CinV = CNT_V(CinCnt) / AMP_CIN;
         const Vbatt = CNT_V(VinCnt) / AMP_VIN + CinV + VCE;
         const Ibatt = CinV / SHUNT_IN;
@@ -281,82 +233,68 @@ void      cUiUpdatePower(void)
         return r;
     }
 
-    let nonActivated = 0;
     function detectDevices() {
-        control.dmesg(`detect devices (hash ${hashDevices()})`)
-        const conns = analogMM.slice(AnalogOff.InConn, DAL.NUM_INPUTS)
-        let numChanged = 0;
-        const uartSensors: SensorInfo[] = [];
+        control.dmesg(`DETECT DEVICES (hash ${hashDevices()})`);
+        const conns = analogMM.slice(AnalogOff.InConn, DAL.NUM_INPUTS);
 
         for (const sensorInfo of sensorInfos) {
-            const newConn = conns[sensorInfo.port]
-            if (newConn == sensorInfo.connType
-                && sensorInfo.sensor
-                && sensorInfo.sensor.isActive()) {
-                if (newConn == DAL.CONN_INPUT_UART)
-                    uartSensors.push(sensorInfo);
+            const newConn = conns[sensorInfo.port];
+            if (newConn == sensorInfo.connType && sensorInfo.sensor && sensorInfo.sensor.isActive()) {
                 continue;
             }
-            numChanged++
-            sensorInfo.connType = newConn
-            sensorInfo.devType = DAL.DEVICE_TYPE_NONE
+            sensorInfo.connType = newConn;
+            sensorInfo.devType = DAL.DEVICE_TYPE_NONE;
             if (newConn == DAL.CONN_INPUT_UART) {
-                control.dmesg(`new UART connection at ${sensorInfo.port}`)
+                const status = getUartStatus(sensorInfo.port);
+                control.dmesg(`new UART connection at port ${sensorInfo.port} with status ${status}`);
                 updateUartMode(sensorInfo.port, 0);
-                uartSensors.push(sensorInfo);
             } else if (newConn == DAL.CONN_NXT_IIC) {
-                control.dmesg(`new IIC connection at ${sensorInfo.port}`)
-                sensorInfo.devType = DAL.DEVICE_TYPE_IIC_UNKNOWN
-                sensorInfo.iicid = readIICID(sensorInfo.port)
-                control.dmesg(`IIC ID ${sensorInfo.iicid.length}`)
+                sensorInfo.devType = DAL.DEVICE_TYPE_IIC_UNKNOWN;
+                sensorInfo.iicid = readIICID(sensorInfo.port);
+                control.dmesg(`new IIC connection at port ${sensorInfo.port} with ID ${sensorInfo.iicid.length}`);
             } else if (newConn == DAL.CONN_INPUT_DUMB) {
-                control.dmesg(`new DUMB connection at ${sensorInfo.port}`)
-                // TODO? for now assume touch
-                sensorInfo.devType = DAL.DEVICE_TYPE_TOUCH
+                control.dmesg(`new DUMB connection at port ${sensorInfo.port}`);
+                sensorInfo.devType = DAL.DEVICE_TYPE_TOUCH; // TODO? for now assume touch sensor
             } else if (newConn == DAL.CONN_NONE || newConn == 0) {
-                //control.dmesg(`disconnect at port ${sensorInfo.port}`)
+                control.dmesg(`disconnect at port ${sensorInfo.port}`);
             } else {
-                control.dmesg(`unknown connection type: ${newConn} at ${sensorInfo.port}`)
+                control.dmesg(`unknown connection type ${newConn} at port ${sensorInfo.port}`);
             }
         }
 
-        if (uartSensors.length > 0) {
+        const uartSens = sensorInfos.filter(si => si.connType == DAL.CONN_INPUT_UART).length;
+        if (uartSens > 0) {
             setUartModes();
-            for (const sensorInfo of uartSensors) {
-                let uinfo = readUartInfo(sensorInfo.port, 0)
-                sensorInfo.devType = uinfo[TypesOff.Type]
+            for (const sensorInfo of sensorInfos.filter(si => si.connType == DAL.CONN_INPUT_UART && si.devType == DAL.CONN_NONE)) {
+                const uinfo = readUartInfo(sensorInfo.port, 0);
+                sensorInfo.devType = uinfo[TypesOff.Type];
                 const mode = uinfo[TypesOff.Mode];
-                control.dmesg(`UART type ${sensorInfo.devType} mode ${mode}`)
+                control.dmesg(`UART type ${sensorInfo.devType} mode ${mode} at port ${sensorInfo.port}`);
             }
         }
 
-        if (numChanged == 0 && nonActivated == 0)
-            return
-
-        //control.dmesg(`updating sensor status`)
-        nonActivated = 0;
-        for (const sensorInfo of sensorInfos) {
+        control.dmesg(`UPDATE SENSOR STATUS`);
+        for (const sensorInfo of sensorInfos.filter(si => !si.sensor)) {
             if (sensorInfo.devType == DAL.DEVICE_TYPE_IIC_UNKNOWN) {
-                sensorInfo.sensor = sensorInfo.sensors.filter(s => s._IICId() == sensorInfo.iicid)[0]
+                sensorInfo.sensor = sensorInfo.sensors.filter(s => s._IICId() == sensorInfo.iicid)[0];
                 if (!sensorInfo.sensor) {
-                    control.dmesg(`sensor not found for iicid=${sensorInfo.iicid} at ${sensorInfo.port}`)
-                    nonActivated++;
+                    control.dmesg(`sensor not found for iicid=${sensorInfo.iicid} at port ${sensorInfo.port}`);
                 } else {
-                    control.dmesg(`sensor connected iicid=${sensorInfo.iicid} at ${sensorInfo.port}`)
-                    sensorInfo.sensor._activated()
+                    control.dmesg(`sensor connected iicid=${sensorInfo.iicid} at port ${sensorInfo.port}`);
+                    sensorInfo.sensor._activated();
                 }
             } else if (sensorInfo.devType != DAL.DEVICE_TYPE_NONE) {
-                sensorInfo.sensor = sensorInfo.sensors.filter(s => s._deviceType() == sensorInfo.devType)[0]
+                sensorInfo.sensor = sensorInfo.sensors.filter(s => s._deviceType() == sensorInfo.devType)[0];
                 if (!sensorInfo.sensor) {
-                    control.dmesg(`sensor not found for type=${sensorInfo.devType} at ${sensorInfo.port}`)
-                    nonActivated++;
+                    control.dmesg(`sensor not found for type=${sensorInfo.devType} at port ${sensorInfo.port}`);
                 } else {
-                    control.dmesg(`sensor connected type=${sensorInfo.devType} at ${sensorInfo.port}`)
-                    sensorInfo.sensor._activated()
+                    control.dmesg(`sensor connected type=${sensorInfo.devType} at port ${sensorInfo.port}`);
+                    sensorInfo.sensor._activated();
                 }
             }
         }
-        //control.dmesg(`detect devices done`)
+
+        control.dmesg(`DETECT DEVICES DONE`);
     }
 
     export class Sensor extends control.Component {
@@ -392,16 +330,12 @@ void      cUiUpdatePower(void)
             return sensorInfos[this._port].sensor == this
         }
 
-        _query() {
-            return 0
-        }
-
-        _info(): string {
-            return this._query().toString();
+        _query(): number[] {
+            return [0];
         }
 
-        _infoArr(): string[] {
-            return [this._query().toString()];
+        _info(): string[] {
+            return [this._query()[0].toString()];
         }
 
         _update(prev: number, curr: number) {
@@ -520,7 +454,28 @@ void      cUiUpdatePower(void)
         }
     }
 
-    export const iicsensor = new IICSensor(3)
+    export const i2csensor1 = new IICSensor(1);
+    export const i2csensor2 = new IICSensor(2);
+    export const i2csensor3 = new IICSensor(3);
+    export const i2csensor4 = new IICSensor(4);
+
+    function readUartInfo(port: number, mode: number) {
+        let buf = output.createBuffer(UartCtlOff.Size);
+        buf[UartCtlOff.Port] = port;
+        buf[UartCtlOff.Mode] = mode;
+        uartMM.ioctl(IO.UART_READ_MODE_INFO, buf);
+        //control.dmesg(`UART_READ_MODE p:${port} t:${buf[TypesOff.Type]} c:${buf[TypesOff.Connection]} m:${buf[TypesOff.Mode]} n:${buf.slice(0, 12).toHex()}`);
+        return buf;
+    }
+
+    export function readIICID(port: number) {
+        const buf = output.createBuffer(IICStr.Size);
+        buf[IICStr.Port] = port;
+        IICMM.ioctl(IO.IIC_READ_TYPE_INFO, buf);
+        const manufacturer = bufferToString(buf.slice(IICStr.Manufacturer, 8));
+        const sensorType = bufferToString(buf.slice(IICStr.SensorType, 8));
+        return manufacturer + sensorType;
+    }
 
     function uartReset(port: number) {
         if (port < 0) return
@@ -537,16 +492,18 @@ void      cUiUpdatePower(void)
     }
 
     function waitNonZeroUartStatus(port: number) {
-        while (true) {
-            if (port < 0) return 0
-            let s = getUartStatus(port)
-            if (s) return s
-            pause(25)
+        let retry = 20;
+        while (retry-- > 0) {
+            const s = getUartStatus(port);
+            if (s) return s;
+            control.dmesg(`UART status 0 at port ${port}, waiting...`);
+            pause(25);
         }
+        return 0;
     }
 
     function uartClearChange(port: number) {
-        control.dmesg(`UART clear change`);
+        control.dmesg(`UART clear change at port ${port}`);
         while (true) {
             let status = getUartStatus(port)
             if (port < 0) break
@@ -557,18 +514,17 @@ void      cUiUpdatePower(void)
             devcon.setNumber(NumberFormat.Int8LE, DevConOff.Connection + port, DAL.CONN_INPUT_UART)
             devcon.setNumber(NumberFormat.Int8LE, DevConOff.Type + port, 0)
             devcon.setNumber(NumberFormat.Int8LE, DevConOff.Mode + port, 0)
-
+            control.dmesg(`UART_CLEAR_CHANGED status ${status} ${devcon.toHex()}`)
             uartMM.ioctl(IO.UART_CLEAR_CHANGED, devcon)
 
-            uartMM.setNumber(NumberFormat.Int8LE, UartOff.Status + port,
-                getUartStatus(port) & 0xfffe)
+            uartMM.setNumber(NumberFormat.Int8LE, UartOff.Status + port, getUartStatus(port) & 0xfffe)
             pause(10)
         }
     }
 
     function setUartModes() {
-        control.dmesg(`UART set modes 0x${devcon.toHex()}`)
-        uartMM.ioctl(IO.UART_SET_CONN, devcon)
+        control.dmesg(`UART_SET_CONN ${devcon.toHex()}`);
+        uartMM.ioctl(IO.UART_SET_CONN, devcon);
         const ports: number[] = [];
         for (let port = 0; port < DAL.NUM_INPUTS; ++port) {
             if (devcon.getNumber(NumberFormat.Int8LE, DevConOff.Connection + port) == DAL.CONN_INPUT_UART) {
@@ -578,38 +534,36 @@ void      cUiUpdatePower(void)
 
         while (ports.length) {
             const port = ports.pop();
-            const status = waitNonZeroUartStatus(port)
-            control.dmesg(`UART status ${status} at ${port}`);
+            const status = waitNonZeroUartStatus(port);
+            control.dmesg(`UART status ${status} at port ${port}`);
             if (!(status & UART_DATA_READY))
                 setUartMode(port, devcon[DevConOff.Mode + port]);
         }
     }
 
     function updateUartMode(port: number, mode: number) {
-        control.dmesg(`UART update mode to ${mode} at ${port}`)
+        control.dmesg(`UART update mode to ${mode} at port ${port}`);
         devcon.setNumber(NumberFormat.Int8LE, DevConOff.Connection + port, DAL.CONN_INPUT_UART)
         devcon.setNumber(NumberFormat.Int8LE, DevConOff.Type + port, 33)
         devcon.setNumber(NumberFormat.Int8LE, DevConOff.Mode + port, mode)
     }
-
-    const UART_PORT_CHANGED = 1
-    const UART_DATA_READY = 8
+    
     function setUartMode(port: number, mode: number) {
         while (true) {
-            if (port < 0) return
+            if (port < 0) return;
             updateUartMode(port, mode);
-            control.dmesg(`UART set mode 0x${devcon.toHex()}`)
-            uartMM.ioctl(IO.UART_SET_CONN, devcon)
-            let status = waitNonZeroUartStatus(port)
+            control.dmesg(`UART_SET_CONN ${devcon.toHex()}`);
+            uartMM.ioctl(IO.UART_SET_CONN, devcon);
+            let status = waitNonZeroUartStatus(port);
             if (status & UART_PORT_CHANGED) {
-                control.dmesg(`UART clear changed at ${port}`)
-                uartClearChange(port)
+                control.dmesg(`UART clear changed at port ${port}`);
+                uartClearChange(port);
             } else {
-                control.dmesg(`UART status ${status}`);
+                control.dmesg(`UART status ${status} at port ${port}`);
                 if (status & UART_DATA_READY)
                     break;
             }
-            pause(10)
+            pause(10);
         }
     }
 
@@ -638,7 +592,7 @@ void      cUiUpdatePower(void)
 
     export function transactionIIC(port: number, deviceAddress: number, writeBuf: number[], readLen: number) {
         if (port < 0) return;
-        let iicdata = output.createBuffer(IICDat.Size)
+        const iicdata = output.createBuffer(IICDat.Size)
         iicdata.setNumber(NumberFormat.Int8LE, IICDat.Port, port)
         iicdata.setNumber(NumberFormat.Int8LE, IICDat.Repeat, 0)
         iicdata.setNumber(NumberFormat.Int16LE, IICDat.Time, 0)
diff --git a/libs/core/pxt.json b/libs/core/pxt.json
index d2b1a923..b72d6d61 100644
--- a/libs/core/pxt.json
+++ b/libs/core/pxt.json
@@ -13,6 +13,7 @@
         "timer.ts",
         "serialnumber.cpp",
         "buttons.ts",
+        "indicator.ts",
         "screen.cpp",
         "battery.ts",
         "output.cpp",
diff --git a/libs/ev3/brick.ts b/libs/ev3/brick.ts
index 16c073ef..d8c5f10c 100644
--- a/libs/ev3/brick.ts
+++ b/libs/ev3/brick.ts
@@ -6,7 +6,7 @@ namespace brick {
     //% help=reference/brick/exit-program
     //% weight=10
     //% blockGap=8
-    //% group="Buttons"
+    //% group="Program"
     export function exitProgram() {
         control.reset();
     }
diff --git a/libs/ev3/ns.ts b/libs/ev3/ns.ts
index 6a0f436d..812781b8 100644
--- a/libs/ev3/ns.ts
+++ b/libs/ev3/ns.ts
@@ -1,5 +1,5 @@
 //% color="#68C3E2" weight=100 icon="\uf106"
-//% groups='["Buttons", "Screen", "Power"]'
+//% groups='["Buttons", "Indicator", "Screen", "Power", "Program"]'
 //% labelLineWidth=60
 namespace brick {
 }
@@ -7,6 +7,7 @@ namespace brick {
 //% color="#C8509B" weight=95 icon="\uf10f"
 //% labelLineWidth=100
 //% groups='["Touch Sensor", "Color Sensor", "Ultrasonic Sensor", "Gyro Sensor", "Infrared Sensor", "Remote Infrared Beacon", "Calibration"]'
+//% subcategories='["NXT", "HiTechnic"]'
 namespace sensors {
 }
 
diff --git a/libs/gyro-sensor/gyro.ts b/libs/gyro-sensor/gyro.ts
index 208a748f..7e73153e 100644
--- a/libs/gyro-sensor/gyro.ts
+++ b/libs/gyro-sensor/gyro.ts
@@ -23,10 +23,10 @@ namespace sensors {
             return DAL.DEVICE_TYPE_GYRO
         }
 
-        _query(): number {
+        _query() {
             const v = this.getNumber(NumberFormat.Int16LE, 0);
             this._angle.integrate(v - this._drift);
-            return v;
+            return [v];
         }
 
         setMode(m: GyroSensorMode) {
@@ -73,7 +73,7 @@ namespace sensors {
             this.poke();
             if (this._calibrating)
                 pauseUntil(() => !this._calibrating, 2000);
-            return this._query() - this._drift;
+            return this._query()[0] - this._drift;
         }
 
         /**
@@ -253,21 +253,21 @@ namespace sensors {
             const n = 10;
             let d = 0;
             for (let i = 0; i < n; ++i) {
-                d += this._query();
+                d += this._query()[0];
                 pause(20);
             }
             this._drift = d / n;
             this._angle.reset();
         }
 
-        _info(): string {
+        _info() {
             if (this._calibrating)
-                return "cal...";
+                return ["cal..."];
 
-            let r = `${this._query()}r`;
+            let r = `${this._query()[0]}r`;
             if (this._drift != 0)
                 r += `-${this._drift | 0}`;
-            return r;
+            return [r];
         }
     }
 
diff --git a/libs/infrared-sensor/ir.ts b/libs/infrared-sensor/ir.ts
index cadecac7..99763386 100644
--- a/libs/infrared-sensor/ir.ts
+++ b/libs/infrared-sensor/ir.ts
@@ -155,19 +155,19 @@ namespace sensors {
 
         _query() {
             if (this.mode == InfraredSensorMode.RemoteControl)
-                return mapButton(this.getNumber(NumberFormat.UInt8LE, this._channel));
+                return [mapButton(this.getNumber(NumberFormat.UInt8LE, this._channel))];
             else if (this.mode == InfraredSensorMode.Proximity) {
-                return this.getNumber(NumberFormat.UInt16LE, 0) & 0x0fff;
+                return [this.getNumber(NumberFormat.UInt16LE, 0) & 0x0fff];
             }
-            return 0
+            return [0];
         }
 
-        _info(): string {
+        _info() {
             if (this.mode == InfraredSensorMode.RemoteControl)
-                return "remote";
+                return ["remote"];
             else if (this.mode == InfraredSensorMode.Proximity)
-                return `${this._query()}%`;
-            return "";
+                return [`${this._query()}%`];
+            return [""];
         }
 
         _update(prev: number, curr: number) {
diff --git a/libs/screen/targetoverrides.ts b/libs/screen/targetoverrides.ts
index 0d0005a9..d10b7ecf 100644
--- a/libs/screen/targetoverrides.ts
+++ b/libs/screen/targetoverrides.ts
@@ -272,13 +272,13 @@ namespace brick {
             const x = (si.port() - 1) * col + 2;
             const inf = si._info();
             if (screenMode != ScreenMode.Ports) return;
-            if (inf == "array") {
-                let infArr = si._infoArr();
+            if (inf.length > 1) {
+                let infArr = si._info();
                 for (let data = 0, str = Math.min(infArr.length + 1, 4); data < Math.min(infArr.length, 3); data++, str--) {
                     screen.print(infArr[data], x, h - str * lineHeight8, 1, infArr[data].length > 4 ? image.font5 : image.font8);
                 }
-            } else if (inf) {
-                screen.print(inf, x, h - 2 * lineHeight8, 1, inf.length > 4 ? image.font5 : image.font8);
+            } else if (inf[0]) {
+                screen.print(inf[0], x, h - 2 * lineHeight8, 1, inf[0].length > 4 ? image.font5 : image.font8);
             }
         }
     }
diff --git a/libs/touch-sensor/touch.ts b/libs/touch-sensor/touch.ts
index 854220b4..8c3fb979 100644
--- a/libs/touch-sensor/touch.ts
+++ b/libs/touch-sensor/touch.ts
@@ -12,11 +12,11 @@ namespace sensors {
         }
 
         _query() {
-            return this._readPin6() > 2500 ? 1 : 0
+            return this._readPin6() > 2500 ? [1] : [0];
         }
 
-        _info(): string {
-            return this._query() ? "pres" : "rel";
+        _info() {
+            return this._query() ? ["pres"] : ["rel"];
         }
 
         _update(prev: number, curr: number) {
diff --git a/libs/ultrasonic-sensor/ultrasonic.ts b/libs/ultrasonic-sensor/ultrasonic.ts
index 8ed8bc22..a9fe0690 100644
--- a/libs/ultrasonic-sensor/ultrasonic.ts
+++ b/libs/ultrasonic-sensor/ultrasonic.ts
@@ -23,12 +23,12 @@ namespace sensors {
             return DAL.DEVICE_TYPE_ULTRASONIC
         }
 
-        _query(): number {
-            return ((this.getNumber(NumberFormat.UInt16LE, 0) & 0x0fff) / 10) >> 0; // range is 0..2550, in 0.1 cm increments.
+        _query() {
+            return [((this.getNumber(NumberFormat.UInt16LE, 0) & 0x0fff) / 10) >> 0]; // range is 0..2550, in 0.1 cm increments.
         }
 
-        _info(): string {
-            return `${this.distance()}cm`
+        _info() {
+            return [`${this.distance()}cm`];
         }
 
         _update(prev: number, curr: number) {
@@ -87,7 +87,7 @@ namespace sensors {
             this.poke();
             // it supposedly also has an inch mode, but we stick to cm
             this._setMode(0)
-            return this._query();
+            return this._query()[0];
         }
 
 
diff --git a/package.json b/package.json
index b000b91e..8846277c 100644
--- a/package.json
+++ b/package.json
@@ -46,7 +46,7 @@
   },
   "dependencies": {
     "pxt-common-packages": "11.1.2",
-    "pxt-core": "9.1.10"
+    "pxt-core": "9.1.23"
   },
   "scripts": {
     "test": "node node_modules/pxt-core/built/pxt.js travis"
diff --git a/theme/style.less b/theme/style.less
index cd1bcf93..20931df9 100644
--- a/theme/style.less
+++ b/theme/style.less
@@ -76,6 +76,11 @@
     min-width: 2.0rem;
 }
 
+/* lego and microsoft logos separator */
+.menubar .ui.menu .brand:before {
+    border-left: 2px solid #888888;
+}
+
 /* Editor menu toggle */
 #root:not(.hc) #editordropdown {
     padding: 0 1em;
@@ -102,7 +107,7 @@
 }
 
 .menubar .ui.item.editor-menuitem .item.toggle {
-    height: 45px;
+    height: 100%;
 }
 
 .sandboxfooter a:not(.thin) {