diff --git a/src/main.py b/src/main.py
index f7d1166..8ccfc88 100644
--- a/src/main.py
+++ b/src/main.py
@@ -2,8 +2,9 @@
 import machine
 import socket
 import time
+import ujson as json
 from wifi import WifiSTA
-
+from credentials import *
 
 ## Pins
 PIN_UP = 14 # D5
@@ -15,76 +16,47 @@ PIN_B1 =  0 # D2
 PIN_B2 =  4 # D3
 ## Delay
 DELAY_CMD = 0.1
-DELAY_IRQ = 0.1
 ## HOST
-RX_ADDR = ("192.168.11.220", 80)
-# RX_ADDR = ("192.168.0.1", 80)
+# RX_ADDR = ("192.168.11.220", 80)
+# RX_ADDR = ("192.168.11.217", 8000)
+RX_ADDR = ("192.168.0.1", 8000)
 
-ts_irq = 0
-s = None
+## Runtime
+wifiSTA = None
 
-def handle_btn_up(pin):
-    global ts_irq
-    t = time.time()
-    if t > (ts_irq + DELAY_IRQ):
-        ts_irq = t
-        send_cmd("rotate")
-
-# def handle_btn_b1(pin):
-#     global ts_irq
-#     t = time.time()
-#     if t > (ts_irq + DELAY_IRQ):
-#         ts_irq = t
-#         send_cmd("b1")
-
-# def handle_btn_b2(pin):
-#     global ts_irq
-#     t = time.time()
-#     if t > (ts_irq + DELAY_IRQ):
-#         ts_irq = t
-#         send_cmd("b2")
-
-def send_cmd(cmd):
-    global s
-    print("cmd: {}".format(cmd))
+def send_data(s, data):
+    print("data: {}".format(data))
     try:
-        s.sendto(cmd.encode(), RX_ADDR)
+        s.sendto(data.encode(), RX_ADDR)
     except Exception as ex:
         print("Exception Type:{}, args: {}".format(type(ex).__name__, ex.args))
 
 def main():
-    global s
-    wifiSTA = WifiSTA()
-    ## initialize buttons and IRQs
+    global wifiSTA
+    wifiSTA = WifiSTA(SSID, PASS)
+    # initialize buttons
     btn_up = machine.Pin(PIN_UP, machine.Pin.IN, machine.Pin.PULL_UP)
-    btn_up.irq(trigger=machine.Pin.IRQ_FALLING, handler=handle_btn_up)
     btn_dn = machine.Pin(PIN_DN, machine.Pin.IN, machine.Pin.PULL_UP)
-    # btn_dn.irq(trigger=machine.Pin.IRQ_FALLING, handler=handle_btn_dn)
     btn_le = machine.Pin(PIN_LE, machine.Pin.IN, machine.Pin.PULL_UP)
-    # btn_le.irq(trigger=machine.Pin.IRQ_FALLING, handler=handle_btn_le)
     btn_ri = machine.Pin(PIN_RI, machine.Pin.IN, machine.Pin.PULL_UP)
-    # btn_ri.irq(trigger=machine.Pin.IRQ_FALLING, handler=handle_btn_ri)
     btn_b1 = machine.Pin(PIN_B1, machine.Pin.IN, machine.Pin.PULL_UP)
-    # btn_b1.irq(trigger=machine.Pin.IRQ_FALLING, handler=handle_btn_b1)
     btn_b2 = machine.Pin(PIN_B2, machine.Pin.IN, machine.Pin.PULL_UP)
-    # btn_b2.irq(trigger=machine.Pin.IRQ_FALLING, handler=handle_btn_b2)
+    # initialize socket
     s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
-
+    # runtime
+    buttons = {"btn_up": btn_up, "btn_dn": btn_dn, "btn_le": btn_le,
+               "btn_ri": btn_ri, "btn_b1": btn_b1, "btn_b2": btn_b2}
+    values = {"btn_up": 0, "btn_dn": 0, "btn_le": 0,
+              "btn_ri": 0, "btn_b1": 0, "btn_b2": 0}
+    # loop
     while True:
-        if not btn_le.value():
-            send_cmd("left")
-        elif not btn_ri.value():
-            send_cmd("right")
-        elif not btn_b1.value():
-            send_cmd("accel")
-        elif not btn_b2.value():
-            send_cmd("decel")
-        elif not btn_up.value():
-            send_cmd("rotate")
-        elif not btn_dn.value():
-            send_cmd("stop")
+        wifiSTA.check()
 
+        for name, button in buttons.items():
+            values[name] = not button.value()
+
+        send_data(s, json.dumps(values))
         time.sleep(DELAY_CMD)
 
 if __name__ == "__main__":
-    main()
\ No newline at end of file
+    main()
diff --git a/src/wifi.py b/src/wifi.py
index b7c8d66..0879718 100644
--- a/src/wifi.py
+++ b/src/wifi.py
@@ -1,4 +1,3 @@
-from credentials import *
 import network
 import time
 
@@ -9,35 +8,41 @@ dns = "192.168.0.1"
 
 
 class WifiAP:
-    def __init__(self):
-        self.if_ap = network.WLAN(network.AP_IF)
+    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=SSID, password=PASS)
+        self.if_ap.config(essid=self.ssid, password=self.password)
         print("network config {}".format(self.if_ap.ifconfig()))
 
 class WifiSTA:
-    def __init__(self):
+    def __init__(self, ssid, password):
+        self.ssid = ssid
+        self.password = password
+        # AP: disable
         self.if_ap = network.WLAN(network.AP_IF)
-        self.if_sta = network.WLAN(network.STA_IF)
         self.if_ap.active(False)
+        # STA: enable
+        self.if_sta = network.WLAN(network.STA_IF)
         self.if_sta.active(True)
-        self.if_sta.connect(SSID, PASS)
-        # self.wifi_thread = threading.Thread(target=self.wifi_thread_fn)
+
+    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(self.if_sta.ifconfig()))
-        # self.wifi_thread.start()
-
-    # def wifi_thread_fn(self):
-    #     while True:
-    #         if not self.if_sta.isconnected():
-    #             print("reconnecting...")
-    #             self.if_sta.connect(SSID, PASS)
-    #             while not self.if_sta.isconnected():
-    #                 time.sleep(0.1)
-    #             print("network config {}".format(self.if_sta.ifconfig()))
-    #         else:
-    #             time.sleep(0.1)
\ No newline at end of file
+        print("network config {}".format(self.if_sta.ifconfig()))
\ No newline at end of file