diff --git a/arduino/arduino.ino b/arduino/arduino.ino
index 5fa28c0..5ba69f8 100644
--- a/arduino/arduino.ino
+++ b/arduino/arduino.ino
@@ -18,30 +18,30 @@ void setup() {
   Serial.begin(9600);
 }
 
-int hex;
+uint8_t hex;
+uint8_t stored[3];
+
 int rgb;
 int led;
 
-int stored[3];
-
 void loop() {
   if (Serial.available() > 0) {
     int data;
-    switch (data = Serial.read()) {        
-      case 'n':
-        nextColour();
-        break;
-      case 'l': // end of LED
-        nextLed();
+    switch (data = Serial.read()) {
+      case 'r':
+        resetState();
         break;
       case 'q':
         complete();
         break;
-      case 'r':
-        resetState();
+      case 'l': // end of LED
+        nextLed();
+        break;
+      case 'n':
+        nextColour();
         break;
       default:
-        hex = (hex << 1) + charMap(data);
+        hex = (hex << 4) + charMap(data);
         break;
     }
   }
@@ -54,10 +54,10 @@ void nextColour() {
 
 void nextLed() {
   CRGB color = CRGB(stored[0], stored[1], stored[2]);
-    
+
   int strip = led / NUM_SQUARES_PER_STRIP;
   int start = (led * NUM_LEDS_PER_SQUARE) - (strip * NUM_LEDS_PER_STRIP);
-  
+
   for (int i = start; i < start + NUM_LEDS_PER_SQUARE; i++) {
     leds[strip][i] = color;
   }
@@ -75,8 +75,8 @@ void resetState() {
   led = rgb = hex = 0;
 }
 
-int charMap(char that) {
-  switch (that) {
+uint8_t charMap(char c) {
+  switch (c) {
     case '0':
       return 0;
     case '1':
@@ -109,6 +109,7 @@ int charMap(char that) {
       return 14;
     case 'f':
       return 15;
+    default:
+      return 0;
   }
-  return -1;
 }
diff --git a/python/server.py b/python/server.py
index 93a4c30..805149d 100755
--- a/python/server.py
+++ b/python/server.py
@@ -1,15 +1,48 @@
 #!/usr/bin/python3
 
+from flask import Flask, request
+import threading
 import serial
 
-with serial.Serial('/dev/ttyACM0') as ser:
-    while True:
-        for i in range(30): # selected LED
-            for j in range(30): # LED
-                for k in range(3): # colour
-                    for l in range(2):
-                        ser.write(b'f' if (i==j and k==1) else b'0')
-                    ser.write(b'n')
-                ser.write(b'l')
-            ser.write(b'q')
+app = Flask(__name__)
+
+data = ""
+lock = threading.Lock()
+
+@app.route('/update', methods=['PUT'])
+def update():
+  grid = request.json['data']
+  grid_string = prepare_grid(grid)
+
+  with lock:
+    data = grid_string
+
+  return grid_string
+
+def prepare_grid(grid):
+  # follow down up down down up down
+  HEIGHT = 5
+  WIDTH = 6
+
+  out = ""
+  for x in range(WIDTH):
+    for y in (range(0,HEIGHT,1) if x%3 == 1 else range(HEIGHT-1,-1,-1)):
+      for r in range(3):
+        out += hex(grid[x][y][r])[2:] + 'n'
+      out += 'l'
+  out += 'q'
+  return out
+
+def serial():
+  with serial.Serial('/dev/ttyACM0', 9600, timeout=1) as ser:
+    with lock:
+      if data != '':
+        serial.write(bytes(data, 'ascii'))
+        data = ''
+
+serial_thread = threading.Thread(target=serial)
+serial_thread.start()
+
+if __name__ == '__main__':
+  app.run(host='0.0.0.0')