diff --git a/src/esc.py b/src/esc.py
index 530d6a3..2d29e36 100644
--- a/src/esc.py
+++ b/src/esc.py
@@ -3,7 +3,7 @@ from time import sleep
 
 DELTA = 10
 DELTA_TURN = 5
-DELTA_MAX = 30
+DELTA_TURN_MAX = 60
 
 class Esc:
     def __init__(self, pin_m1_ena, pin_m1_in1, pin_m1_in2,
@@ -11,66 +11,76 @@ class Esc:
         self.m1 = Motor("m1", pin_m1_ena, pin_m1_in1, pin_m1_in2)
         self.m2 = Motor("m2", pin_m2_ena, pin_m2_in1, pin_m2_in2)
 
-    def fwd(self):
+    ## regular movement
+    def accel(self):
         speed = min((self.m1.speed + self.m2.speed)/2 + DELTA, 100)
         self.m1.set_speed(speed)
         self.m2.set_speed(speed)
 
-    def rev(self):
+    def decel(self):
         speed = max((self.m1.speed + self.m2.speed)/2 - DELTA, -100)
         self.m1.set_speed(speed)
         self.m2.set_speed(speed)
 
+    # m1: left, m2: right
     def left(self):
         s1 = self.m1.speed
         s2 = self.m2.speed
         avg = (s1 + s2)/2
         delta = s2 - s1
 
-        if delta <= (DELTA_MAX - 2*DELTA_TURN):
+        if delta <= (DELTA_TURN_MAX - 2*DELTA_TURN):
             self.m1.dec(DELTA_TURN)
             self.m2.inc(DELTA_TURN)
-        elif delta == DELTA_MAX:
-            print("delta reached, not changing")
-        elif delta > (DELTA_MAX):
-            print("delta exceeded, resetting")
+        elif delta > (DELTA_TURN_MAX):
+            # print("delta exceeded, resetting")
             self.m1.set_speed(avg - DELTA_TURN)
             self.m2.set_speed(avg + DELTA_TURN)
+        # elif delta == DELTA_TURN_MAX:
+        #     print("delta reached, not changing")
 
     def right(self):
         s1 = self.m1.speed
         s2 = self.m2.speed
         avg = (s1 + s2)/2
         delta = s1 - s2
-        if delta <= (DELTA_MAX - 2*DELTA_TURN):
+        if delta <= (DELTA_TURN_MAX - 2*DELTA_TURN):
             self.m1.inc(DELTA_TURN)
             self.m2.dec(DELTA_TURN)
-        elif delta == DELTA_MAX:
-            print("delta reached, not changing")
-        elif delta > (DELTA_MAX):
-            print("delta exceeded, resetting")
+        elif delta > (DELTA_TURN_MAX):
+            # print("delta exceeded, resetting")
             self.m1.set_speed(avg + DELTA_TURN)
             self.m2.set_speed(avg - DELTA_TURN)
+        # elif delta == DELTA_TURN_MAX:
+        #     print("delta reached, not changing")
 
-    # stop
-    def b1(self):
+    ## extra
+    def neutral(self):
+        speed = (self.m1.speed + self.m2.speed)/2
+        self.m1.set_speed(speed)
+        self.m2.set_speed(speed)
+
+    def stop(self):
         self.m1.set_speed(0)
         self.m2.set_speed(0)
 
-    def b2(self):
+    def rotate(self):
         if self.m1.speed >= 0:
             self.m1.set_speed(0)
             self.m2.set_speed(0)
-            sleep(1)
+            sleep(0.25)
             self.m1.set_speed(-50)
             self.m2.set_speed(50)
+            sleep(0.75)
         else:
             self.m1.set_speed(0)
             self.m2.set_speed(0)
-            sleep(1)
+            sleep(0.25)
             self.m1.set_speed(50)
             self.m2.set_speed(-50)
+            sleep(0.75)
+
 
     def get_status(self):
-        s = (self.m1.get_status(), self.m2.get_status())
+        s = "{}, {}".format(self.m1.get_status(), self.m2.get_status())
         return s
\ No newline at end of file
diff --git a/src/main.py b/src/main.py
index 2d7f3e3..27d9721 100644
--- a/src/main.py
+++ b/src/main.py
@@ -1,69 +1,99 @@
 # main.py
 import machine
 import usocket as socket
-from time import sleep
+import time
 from esc import Esc
-from wifi import WifiAP
-from wifi import WifiSTA
+# local
+from credentials import *
+import wifi
+
 # import web
 
-PIN_M1_ENA = 5 # D1
-PIN_M1_IN1 = 4 # D2
-PIN_M1_IN2 = 0 # D3
-PIN_M2_IN1 = 12 # D6
-PIN_M2_IN2 = 13 # D7
-PIN_M2_ENA = 15 # D8
+## Pins
+## M1: left, M2: right
+# PIN_M1_ENA = 5 # D1
+# PIN_M1_IN1 = 4 # D2
+# PIN_M1_IN2 = 0 # D3
+# PIN_M2_IN1 = 12 # D6
+# PIN_M2_IN2 = 13 # D7
+# PIN_M2_ENA = 15 # D8
+## M1: right, M2: left
+PIN_M1_IN1 = 12 # D6
+PIN_M1_IN2 = 13 # D7
+PIN_M1_ENA = 15 # D8
+PIN_M2_ENA = 5 # D1
+PIN_M2_IN1 = 4 # D2
+PIN_M2_IN2 = 0 # D3
+## Parameters
+T_NEUTRAL=0.5
+T_STATUS=2
 
+## Variables
 esc = None
 
 def main():
     print("main")
     global esc
-    wifi_sta = WifiSTA()
-    # wifi_ap = WifiAP()
+    # wifiSTA = wifi.WifiSTA(SSID, PASS)
+    wifiAP = wifi.WifiAP(SSID, PASS)
+    wifiAP.connect()
     esc = Esc(PIN_M1_ENA, PIN_M1_IN1, PIN_M1_IN2,
               PIN_M2_ENA, PIN_M2_IN1, PIN_M2_IN2)
     s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
     s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR, 1)
+    s.settimeout(0.1)
     s.bind(("", 80))
 
+    ts_cmd = 0
+    ts_status = 0
     while True:
+        # wifiSTA.check()
         request = ""
         try:
             request, addr = s.recvfrom(256)
-            req = request.decode()
-
-            print("data: {}, from: {}".format(req, addr))
-            if len(request) == 0:
-                print("no data")
-                continue
-        except:
-            print("error: no data")
+        except OSError as ex:
             pass
+        except Exception as ex:
+            print("Exception Type:{}, args: {}".format(type(ex).__name__, ex.args))
 
-        if "fwd" in req:
-            print("--> fwd")
-            esc.fwd()
+        if len(request) > 0:
+            print('len > 0')
+            ts_cmd = time.time()
+            req = request.decode()
+            print("data: {}, from: {}".format(req, addr))
 
-        elif "left" in req:
-            print("--> left")
-            esc.left()
+            ## buttons
+            if "accel" in req:
+                esc.accel()
+                print(esc.get_status())
+            elif "left" in req:
+                esc.left()
+                print(esc.get_status())
+            elif "decel" in req:
+                esc.decel()
+                print(esc.get_status())
+            elif "right" in req:
+                esc.right()
+                print(esc.get_status())
+            elif "stop" in req:
+                esc.stop()
+                print(esc.get_status())
+            elif "rotate" in req:
+                esc.rotate()
+            else:
+                print("unknown: {}".format(req))
 
-        elif "rev" in req:
-            print("--> rev")
-            esc.rev()
 
-        elif "right" in req:
-            print("--> right")
-            esc.right()
+        if time.time() > (ts_cmd + T_NEUTRAL):
+            ts_cmd = time.time()
+            # print(" -: neutral")
+            esc.neutral()
+            # print(esc.get_status())
 
-        elif "b1" in req:
-            print("--> b1")
-            esc.b1()
+        if time.time() > (ts_status + T_STATUS):
+            ts_status = time.time()
+            print(esc.get_status())
 
-        elif "b2" in req:
-            print("--> b2")
-            esc.b2()
 
 if __name__ == "__main__":
     main()
diff --git a/src/motor.py b/src/motor.py
index a7192c1..2b9c75e 100644
--- a/src/motor.py
+++ b/src/motor.py
@@ -1,5 +1,5 @@
 import machine
-from time import sleep
+import time
 
 
 class Motor:
@@ -16,27 +16,27 @@ class Motor:
         # state
         self.dir = -1
         self.speed = -1
-        sleep(1)
+        time.sleep(1)
         # initialize motors
         self.set_speed(0)
-        print(self.get_status())
 
     def get_status(self):
-        s = "[{}:status] pins {},{} duty {}".format(self.name, self.pin1.value(), self.pin2.value(), self.pwm.duty())
+        s = "[{}:status] pins {},{} duty {}".format(
+            self.name, self.pin1.value(), self.pin2.value(), self.pwm.duty())
         return s
 
     def set_dir(self, dir):
         if self.dir == dir:
             return
         self.dir = dir
-        v1 = 1 if dir == self.DIR_FWD else 0
-        v2 = 0 if dir == self.DIR_FWD else 1
+        v1 = 1 if self.dir == self.DIR_FWD else 0
+        v2 = 0 if self.dir == self.DIR_FWD else 1
         self.pin1.value(v1)
         self.pin2.value(v2)
 
-    def set_speed(self, speed=100):
-        print("[{}:set_speed] {} [-100:100]".format(self.name, speed))
-        if speed < 0:
+    def set_speed(self, speed):
+        # print("{}:set_speed] {} -100:100".format(self.name, speed))
+        if (speed < 0):
             self.set_dir(self.DIR_REV)
         else:
             self.set_dir(self.DIR_FWD)
@@ -50,4 +50,4 @@ class Motor:
 
     def dec(self, delta):
         speed = max(self.speed - delta, -100)
-        self.set_speed(speed)
\ No newline at end of file
+        self.set_speed(speed)
diff --git a/src/wifi.py b/src/wifi.py
index e3a9c1f..0879718 100644
--- a/src/wifi.py
+++ b/src/wifi.py
@@ -1,4 +1,3 @@
-from credentials import *
 import network
 import time
 
@@ -7,25 +6,43 @@ netmask = "255.255.255.0"
 gateway = "192.168.0.1"
 dns = "192.168.0.1"
 
-if_ap = network.WLAN(network.AP_IF)
-if_sta = network.WLAN(network.STA_IF)
 
 class WifiAP:
-    def __init__(self):
-        global if_ap, if_sta
-        if_sta.active(False)
-        if_ap.active(True)
-        if_ap.ifconfig([address, netmask, gateway, dns])
-        if_ap.config(essid=SSID, password=PASS)
-        print("network config {}".format(if_ap.ifconfig()))
+    def __init__(self, ssid, password):
+        self.ssid = ssid
+        self.password = password
+        # STA: disable
+        self.if_sta = network.WLAN(network.STA_IF)
+        self.if_sta.active(False)
+        # AP: enable
+        self.if_ap = network.WLAN(network.AP_IF)
+
+    def connect(self):
+        self.if_ap.active(True)
+        self.if_ap.ifconfig([address, netmask, gateway, dns])
+        self.if_ap.config(essid=self.ssid, password=self.password)
+        print("network config {}".format(self.if_ap.ifconfig()))
 
 class WifiSTA:
-    def __init__(self):
-        global if_ap, if_sta
-        if_ap.active(False)
-        if_sta.active(True)
-        if_sta.connect(SSID, PASS)
-        while not if_sta.isconnected():
-            pass
+    def __init__(self, ssid, password):
+        self.ssid = ssid
+        self.password = password
+        # AP: disable
+        self.if_ap = network.WLAN(network.AP_IF)
+        self.if_ap.active(False)
+        # STA: enable
+        self.if_sta = network.WLAN(network.STA_IF)
+        self.if_sta.active(True)
+
+    def check(self):
+        if not self.if_sta.isconnected():
+            print("wifi down, reconnecting...")
+            self.connect()
+
+    def connect(self):
+        print("connecting wifi")
+        self.if_sta.active(True)
+        self.if_sta.connect(self.ssid, self.password)
+        while not self.if_sta.isconnected():
             time.sleep(0.1)
-        print("network config {}".format(if_sta.ifconfig()))
\ No newline at end of file
+        print("network config {}".format(self.if_sta.ifconfig()))
\ No newline at end of file