diff --git a/robot/cutebot.ts b/robot/cutebot.ts
index f7ee1d20..db43b060 100644
--- a/robot/cutebot.ts
+++ b/robot/cutebot.ts
@@ -23,7 +23,7 @@ namespace microcode {
         } else {
             buf[0] = 0x01
             buf[1] = 0x01
-            buf[2] = lspeed * -1
+            buf[2] = -lspeed
             buf[3] = 0 //补位
         }
         pins.i2cWriteBuffer(STM8_ADDRESSS, buf) //写入左轮
@@ -35,7 +35,7 @@ namespace microcode {
         } else {
             buf[0] = 0x02
             buf[1] = 0x01
-            buf[2] = rspeed * -1
+            buf[2] = rspeed
             buf[3] = 0 //补位
         }
         pins.i2cWriteBuffer(STM8_ADDRESSS, buf) //写入左轮
@@ -73,11 +73,11 @@ namespace microcode {
         constructor() {
             super()
             this.musicVolume = 168
-            this.maxRunSpeed = 35
+            this.maxRunSpeed = 40
             this.maxBackSpeed = 20
-            this.maxTurnSpeed = 30
-            this.maxLineRunSpeed = 25
-            this.maxLineTurnSpeed = 27
+            this.maxTurnSpeed = 60
+            this.maxLineRunSpeed = 28
+            this.maxLineTurnSpeed = 60
 
             pins.setPull(DigitalPin.P8, PinPullMode.PullNone)
             pins.setPull(DigitalPin.P13, PinPullMode.PullNone)
@@ -88,12 +88,6 @@ namespace microcode {
             motors(left, right)
         }
 
-        motorTurn(speed: number) {
-            const op = Math.abs(speed) >> 1
-            if (speed > 0) motors(speed, Math.constrain(this.maxTurnSpeed - speed, 0, op))
-            else motors(Math.constrain(this.maxTurnSpeed + speed, 0, op), -speed)
-        }
-
         headlightsSetColor(red: number, green: number, blue: number) {
             singleheadlights(red, green, blue)
         }
diff --git a/robot/cutebotpro.ts b/robot/cutebotpro.ts
index 0acdea57..70754ecb 100644
--- a/robot/cutebotpro.ts
+++ b/robot/cutebotpro.ts
@@ -230,13 +230,6 @@ namespace microcode {
             pwmCruiseControl(left, right)
         }
 
-        motorTurn(speed: number) {
-            console.log(`speed: ${speed}`)
-            const op = Math.abs(speed) / 3
-            if (speed > 0) pwmCruiseControl(speed, Math.constrain(this.maxTurnSpeed - speed, 0, op))
-            else pwmCruiseControl(Math.constrain(this.maxTurnSpeed + speed, 0, op), -speed)
-        }
-
         headlightsSetColor(red: number, green: number, blue: number) {
             singleHeadlights(CutebotProRGBLight.RGBA, red, green, blue)
         }
diff --git a/robot/keystudiominismartrobot.ts b/robot/keystudiominismartrobot.ts
index af957187..2a75dd21 100644
--- a/robot/keystudiominismartrobot.ts
+++ b/robot/keystudiominismartrobot.ts
@@ -163,15 +163,6 @@ namespace microcode {
             carStop()
         }
 
-        motorTurn(speed: number) {
-            if (speed === 0) {
-                this.motorStop()
-            } else {
-                const dir = speed >= 0 ? DIR.TurnRight : DIR.TurnLeft
-                run(dir, Math.abs(speed))
-            }
-        }
-
         ultrasonicDistance(): number {
             //send trig pulse
             pins.digitalWritePin(TRIG_PIN, 0)
diff --git a/robot/pxt.json b/robot/pxt.json
index 8f0d69de..4ab50d1b 100644
--- a/robot/pxt.json
+++ b/robot/pxt.json
@@ -22,7 +22,7 @@
         "test.ts"
     ],
     "targetVersions": {
-        "target": "6.0.18",
+        "target": "6.0.19",
         "targetId": "microbit"
     },
     "supportedTargets": [
diff --git a/robot/robot.ts b/robot/robot.ts
index 2d69bb49..cc80354a 100644
--- a/robot/robot.ts
+++ b/robot/robot.ts
@@ -19,14 +19,6 @@ namespace microcode.robots {
 
         }
 
-
-        /**
-         * Makes the robot turn at % `speed`. Positive turns clock-wize/right, negative turns counter-clockwize/left.
-         */
-        motorTurn(speed: number): void {
-
-        }
-
         /**
          * Optional: sets the color on the LED array as a 24bit RGB color
          */
diff --git a/robot/robotdriver.ts b/robot/robotdriver.ts
index 6b01bfb6..fd1d7e6e 100644
--- a/robot/robotdriver.ts
+++ b/robot/robotdriver.ts
@@ -136,6 +136,11 @@ namespace microcode {
         }
 
         private updateSpeed() {
+            console.log(`tmode: ${this.targetSpeedMode}`)
+            console.log(`tspeed: ${this.targetSpeed}`)
+            console.log(`cmode: ${this.currentSpeedMode}`)
+            console.log(`cspeed: ${this.currentSpeed}`)
+
             // transition from one mode to the other, robot should stop
             if (this.currentSpeedMode !== this.targetSpeedMode) {
                 const alpha = MODE_TRANSITION_ALPHA
@@ -174,25 +179,32 @@ namespace microcode {
                         }
                     }
                 }
-                console.log(`left: ${left}`)
-                console.log(`right: ${right}`)
-                this.robot.motorRun(left, right)
-                this.showMotorState(left, right)
+                this.setMotorState(left, right)
             } else {
                 let s = this.currentSpeed
                 if (lines)
-                    s = s * Math.min(Math.abs(s), this.robot.maxLineTurnSpeed)
-                console.log(`speed: ${s}`)
-                this.robot.motorTurn(s)
-                this.showMotorState(
-                    s > 0 ? s : 0,
-                    s <= 0 ? 0 : -s
-                )
+                    s = Math.sign(s) * Math.min(Math.abs(s), this.robot.maxLineTurnSpeed)
+                let left = 0
+                let right = 0
+                const op = Math.abs(s) / 3
+                if (s > 0) {
+                    right = Math.constrain(this.robot.maxTurnSpeed + s, 0, op)
+                    left = s
+                } else {
+                    right = -s
+                    left = Math.constrain(this.robot.maxTurnSpeed - s, 0, op)
+                }
+                this.setMotorState(left, right)
             }
         }
 
-        private showMotorState(left: number, right: number) {
+        private setMotorState(left: number, right: number) {
+            left = Math.round(left)
+            right = Math.round(right)
+            this.robot.motorRun(left, right)
             if (this.showConfiguration) return
+            console.log(`left: ${left}`)
+            console.log(`right: ${right}`)
             this.showSingleMotorState(3, left)
             this.showSingleMotorState(1, right)
         }
@@ -269,9 +281,11 @@ namespace microcode {
                 speed > 0
                     ? Math.min(this.robot.maxRunSpeed, speed)
                     : Math.max(-this.robot.maxBackSpeed, speed)
-            this.setHeadlingSpeedColor(speed)
-            this.targetSpeedMode = RobotSpeedMode.Run
-            this.targetSpeed = speed
+            if (this.targetSpeedMode !== RobotSpeedMode.Run || this.targetSpeed !== speed) {
+                this.setHeadlingSpeedColor(speed)
+                this.targetSpeedMode = RobotSpeedMode.Run
+                this.targetSpeed = speed
+            }
         }
 
         motorTurn(speed: number) {
@@ -281,10 +295,11 @@ namespace microcode {
                 speed > 0
                     ? Math.min(this.robot.maxTurnSpeed, speed)
                     : Math.max(-this.robot.maxTurnSpeed, speed)
-            this.setHeadlingSpeedColor(speed)
-            this.targetSpeedMode = RobotSpeedMode.Turn
-            this.targetSpeed = speed
-            this.currentSpeed = 0
+            if (this.targetSpeedMode !== RobotSpeedMode.Turn || this.targetSpeed !== speed) {
+                this.setHeadlingSpeedColor(speed)
+                this.targetSpeedMode = RobotSpeedMode.Turn
+                this.targetSpeed = speed
+            }
         }
 
         motorStop() {
diff --git a/robot/test.ts b/robot/test.ts
index 4c22937a..4f9e7178 100644
--- a/robot/test.ts
+++ b/robot/test.ts
@@ -1,17 +1,23 @@
-//microcode.elecfreaksCuteBot.start()
-microcode.elecfreaksCuteBotPro.start()
+microcode.elecfreaksCuteBot.start()
+//microcode.elecfreaksCuteBotPro.start()
 //microcode.yahboomTinyBit.start()
 //microcode.keyStudioMiniSmartRobot.start()
 //microcode.setMotorDrift(6)
 
 microcode.robotDriver.motorRun(100)
 
+let i = 0
 basic.forever(() => {
     const lines = microcode.robotDriver.currentLineState
-    if (lines === microcode.robots.RobotLineState.Left)
+    console.log(`lines: ${lines}`)
+    if (lines === microcode.robots.RobotLineState.Left) {
         microcode.robotDriver.motorTurn(-100)
-    else if (lines === microcode.robots.RobotLineState.Right)
+    }
+    else if (lines === microcode.robots.RobotLineState.Right) {
         microcode.robotDriver.motorTurn(100)
+    }
+    else if (lines === microcode.robots.RobotLineState.None)
+        microcode.robotDriver.motorTurn(50)
     else
         microcode.robotDriver.motorRun(100)
 })
diff --git a/robot/yahboomtinybit.ts b/robot/yahboomtinybit.ts
index e3ffaad3..8733666c 100644
--- a/robot/yahboomtinybit.ts
+++ b/robot/yahboomtinybit.ts
@@ -140,6 +140,7 @@ namespace microcode {
                 Car_back(-speed, -speed)
         }
 
+        /*
         motorTurn(speed: number): void {
             console.log(`turn: ${speed}`)
             if (speed === 0)
@@ -149,6 +150,7 @@ namespace microcode {
             else
                 Car_left(-speed / 2, -speed)
         }
+        */
 
         headlightsSetColor(red: number, green: number, blue: number) {
             setPwmRGB(red, green, blue)