diff --git a/src/boot.py b/src/boot.py
index 7b00fde..fe411f4 100644
--- a/src/boot.py
+++ b/src/boot.py
@@ -2,4 +2,9 @@
 #import esp
 #esp.osdebug(None)
 import webrepl
+
+def clear_main():
+    import os
+    os.remove('main.py')
+
 webrepl.start()
diff --git a/src/main.py b/src/main.py
index c505a39..108ced9 100644
--- a/src/main.py
+++ b/src/main.py
@@ -1,62 +1,133 @@
+import time
+
 import network
-from mqtt import MQTTClient 
-import machine 
-import time 
- 
-def sub_cb(topic, msg): 
-   print(msg) 
- 
-wlan = network.WLAN(network.STA_IF) 
+from mqtt import MQTTClient
+import machine
+import tsl2591
+import tcs34725
+
+i2c = machine.I2C(-1, machine.Pin(33), machine.Pin(32))
+sensor = tcs34725.TCS34725(i2c)
+
+tsl = tsl2591.Tsl2591(0)
+full, ir = tsl.get_full_luminosity()  # read raw values (full spectrum and ir spectrum)
+lux = tsl.calculate_lux(full, ir)  # convert raw values to lux
+print(lux, full, ir)
+
+running = True
+
+
+def sub_cb(topic, msg):
+    print(msg)
+    global running
+    if msg == b'stop':
+        print('Stopping execution')
+        running = False
+    if msg == b'start' and running is False:
+        print('Resuming execution')
+        running = True
+        main()
+
+
+wlan = network.WLAN(network.STA_IF)
 wlan.active(True)
 
-#wlan.connect("c-base-botnet", auth=(WLAN.WPA2, "wifipassword"), timeout=5000) 
- 
-while not wlan.isconnected():  
-    machine.idle() 
-print("Connected to Wifi\n") 
- 
-client = MQTTClient("windsensor_0", "192.168.178.98",user="", password="", port=1883) 
-#client = MQTTClient("windsensor_0", "mqtt.cbrp3.c-base.org",user="", password="", port=1883) 
-client.set_callback(sub_cb) 
+# wlan.connect("c-base-botnet", auth=(WLAN.WPA2, "wifipassword"), timeout=5000)
+
+while not wlan.isconnected():
+    machine.idle()
+
+print("Connected to Wifi\n")
+
+client = MQTTClient("bioreactor_0", "192.168.178.98", user="", password="", port=1883)
+# client = MQTTClient("windsensor_0", "mqtt.cbrp3.c-base.org",user="", password="", port=1883)
+client.set_callback(sub_cb)
 client.connect()
-client.subscribe(topic="/hackerfleet/sensors/windsensor/control") 
+client.subscribe(topic="/hackerfleet/sensors/bioreactor/control")
+topic_pub = "/hackerfleet/sensors/bioreactor/status"
 
 print("Connected to MQTT")
 
-speedInterrupts = 0
-directionInterrupts = 0
+configuration = {
+    'pin_light': 3,
+    'pin_rotor': 4,
+    'process': [
+        {
+            'action': 'sleep',
+            'duration': 1
+        },
+        {
+            'action': 'start_measurement',
+        },
+        {
+            'action': 'spin_rotor',
+            'duration': 1,
+        },
+        {
+            'action': 'sleep',
+            'duration': 0
+        },
+        {
+            'action': 'stop_measurement',
+        },
+        # {
+        #    'action': 'stop_program'
+        # }
+    ]
+}
 
-speedTicks = 0
-directionTicks = 0
+colour_sensor_address = 0x29
 
-def callbackSpeed(pin):
-    global speedInterrupts
-    speedInterrupts += 1
 
-def callbackDirection(pin):
-    global directionInterrupts
-    directionInterrupts += 1
+def wait(duration):
+    print('Sleeping %s seconds' % duration)
+    time.sleep(duration)
 
-speedPin = machine.Pin(25, machine.Pin.IN, machine.Pin.PULL_UP)
-directionPin = machine.Pin(26, machine.Pin.IN, machine.Pin.PULL_UP)
 
-speedPin.irq(trigger=machine.Pin.IRQ_FALLING, handler=callbackSpeed)
-directionPin.irq(trigger=machine.Pin.IRQ_FALLING, handler=callbackSpeed)
+def switch_pin(pin, state):
+    print('Switching pin %i to %s' % (pin, state))
 
-print("Pin setup done")
 
-while True:
+def start_measurement():
+    print('Starting measurement')
+    data = sensor.read()
+    print(data)
 
-    if speedInterrupts > 0 or directionInterrupts > 0:
-        state = machine.disable_irq()
-        if speedInterrupts > 0:
-            speedTicks += 1
-            speedInterrupts -= 1
-        if directionInterrupts > 0:
-            directionTicks += 1
-            directionInterrupts -= 1
 
-        machine.enable_irq(state)
+def stop_measurement():
+    print('Stopping measurement')
 
-        print("Direction: ", str(directionTicks), " Speed: ", str(speedTicks))
 
+def spin_rotor(duration):
+    print('Stirring')
+    switch_pin(configuration['pin_rotor'], True)
+    wait(duration)
+    print('Stopping')
+    switch_pin(configuration['pin_rotor'], False)
+
+
+def main():
+    global running
+
+    while running:
+        print('Restarting process')
+        client.check_msg()
+        client.publish(topic_pub, "Restarting")
+
+        data = []
+        for item in configuration['process']:
+            client.publish(topic_pub, str(item))
+            if item['action'] == 'sleep':
+                wait(item['duration'])
+            if item['action'] == 'start_measurement':
+                start_measurement()
+            if item['action'] == 'stop_measurement':
+                stop_measurement()
+            if item['action'] == 'spin_rotor':
+                spin_rotor(item['duration'])
+            if item['action'] == 'stop_program':
+                print('Stopping program')
+                running = False
+
+
+main()
diff --git a/src/tcs34725.py b/src/tcs34725.py
new file mode 100644
index 0000000..6374a62
--- /dev/null
+++ b/src/tcs34725.py
@@ -0,0 +1,171 @@
+import time
+import ustruct
+
+#const = lambda x:x
+
+_COMMAND_BIT = const(0x80)
+
+_REGISTER_ENABLE = const(0x00)
+_REGISTER_ATIME = const(0x01)
+
+_REGISTER_AILT = const(0x04)
+_REGISTER_AIHT = const(0x06)
+
+_REGISTER_ID = const(0x12)
+
+_REGISTER_APERS = const(0x0c)
+
+_REGISTER_CONTROL = const(0x0f)
+
+_REGISTER_SENSORID = const(0x12)
+
+_REGISTER_STATUS = const(0x13)
+_REGISTER_CDATA = const(0x14)
+_REGISTER_RDATA = const(0x16)
+_REGISTER_GDATA = const(0x18)
+_REGISTER_BDATA = const(0x1a)
+
+_ENABLE_AIEN = const(0x10)
+_ENABLE_WEN = const(0x08)
+_ENABLE_AEN = const(0x02)
+_ENABLE_PON = const(0x01)
+
+_GAINS = (1, 4, 16, 60)
+_CYCLES = (0, 1, 2, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60)
+
+
+class TCS34725:
+    def __init__(self, i2c, address=0x29):
+        self.i2c = i2c
+        self.address = address
+        self._active = False
+        self.integration_time(2.4)
+        sensor_id = self.sensor_id()
+        if sensor_id not in (0x44, 0x10):
+            raise RuntimeError("wrong sensor id 0x{:x}".format(sensor_id))
+
+    def _register8(self, register, value=None):
+        register |= _COMMAND_BIT
+        if value is None:
+            return self.i2c.readfrom_mem(self.address, register, 1)[0]
+        data = ustruct.pack('<B', value)
+        try:
+            self.i2c.writeto_mem(self.address, register, data)
+        except OSError:
+            print("Could not write to i2c")
+
+    def _register16(self, register, value=None):
+        register |= _COMMAND_BIT
+        if value is None:
+            data = self.i2c.readfrom_mem(self.address, register, 2)
+            return ustruct.unpack('<H', data)[0]
+        data = ustruct.pack('<H', value)
+        self.i2c.writeto_mem(self.address, register, data)
+
+    def active(self, value=None):
+        if value is None:
+            return self._active
+        value = bool(value)
+        if self._active == value:
+            return
+        self._active = value
+        enable = self._register8(_REGISTER_ENABLE)
+        if value:
+            self._register8(_REGISTER_ENABLE, enable | _ENABLE_PON)
+            time.sleep_ms(3)
+            self._register8(_REGISTER_ENABLE,
+                enable | _ENABLE_PON | _ENABLE_AEN)
+        else:
+            self._register8(_REGISTER_ENABLE,
+                enable & ~(_ENABLE_PON | _ENABLE_AEN))
+
+    def sensor_id(self):
+        return self._register8(_REGISTER_SENSORID)
+
+    def integration_time(self, value=None):
+        if value is None:
+            return self._integration_time
+        value = min(614.4, max(2.4, value))
+        cycles = int(value / 2.4)
+        self._integration_time = cycles * 2.4
+        return self._register8(_REGISTER_ATIME, 256 - cycles)
+
+    def gain(self, value):
+        if value is None:
+            return _GAINS[self._register8(_REGISTER_CONTROL)]
+        if value not in _GAINS:
+            raise ValueError("gain must be 1, 4, 16 or 60")
+        return self._register8(_REGISTER_CONTROL, _GAINS.index(value))
+
+    def _valid(self):
+        return bool(self._register8(_REGISTER_STATUS) & 0x01)
+
+    def read(self, raw=False):
+        was_active = self.active()
+        self.active(True)
+        while not self._valid():
+            time.sleep_ms(int(self._integration_time + 0.9))
+        data = tuple(self._register16(register) for register in (
+            _REGISTER_RDATA,
+            _REGISTER_GDATA,
+            _REGISTER_BDATA,
+            _REGISTER_CDATA,
+        ))
+        self.active(was_active)
+        if raw:
+            return data
+        return self._temperature_and_lux(data)
+
+    def _temperature_and_lux(self, data):
+        r, g, b, c = data
+        x = -0.14282 * r + 1.54924 * g + -0.95641 * b
+        y = -0.32466 * r + 1.57837 * g + -0.73191 * b
+        z = -0.68202 * r + 0.77073 * g +  0.56332 * b
+        d = x + y + z
+        n = (x / d - 0.3320) / (0.1858 - y / d)
+        cct = 449.0 * n**3 + 3525.0 * n**2 + 6823.3 * n + 5520.33
+        return cct, y
+
+    def threshold(self, cycles=None, min_value=None, max_value=None):
+        if cycles is None and min_value is None and max_value is None:
+            min_value = self._register16(_REGISTER_AILT)
+            max_value = self._register16(_REGISTER_AILT)
+            if self._register8(_REGISTER_ENABLE) & _ENABLE_AIEN:
+                cycles = _CYCLES[self._register8(_REGISTER_APERS) & 0x0f]
+            else:
+                cycles = -1
+            return cycles, min_value, max_value
+        if min_value is not None:
+            self._register16(_REGISTER_AILT, min_value)
+        if max_value is not None:
+            self._register16(_REGISTER_AIHT, max_value)
+        if cycles is not None:
+            enable = self._register8(_REGISTER_ENABLE)
+            if cycles == -1:
+                self._register8(_REGISTER_ENABLE, enable & ~(_ENABLE_AIEN))
+            else:
+                self._register8(_REGISTER_ENABLE, enable | _ENABLE_AIEN)
+                if cycles not in _CYCLES:
+                    raise ValueError("invalid persistence cycles")
+                self._register8(_REGISTER_APERS, _CYCLES.index(cycles))
+
+    def interrupt(self, value=None):
+        if value is None:
+            return bool(self._register8(_REGISTER_STATUS) & _ENABLE_AIEN)
+        if value:
+            raise ValueError("interrupt can only be cleared")
+        self.i2c.writeto(self.address, b'\xe6')
+
+
+def html_rgb(data):
+    r, g, b, c = data
+    red = pow((int((r/c) * 256) / 255), 2.5) * 255
+    green = pow((int((g/c) * 256) / 255), 2.5) * 255
+    blue = pow((int((b/c) * 256) / 255), 2.5) * 255
+    return red, green, blue
+
+def html_hex(data):
+    r, g, b = html_rgb(data)
+    return "{0:02x}{1:02x}{2:02x}".format(int(r),
+                             int(g),
+                             int(b))
diff --git a/src/tsl2591.py b/src/tsl2591.py
new file mode 100644
index 0000000..9135568
--- /dev/null
+++ b/src/tsl2591.py
@@ -0,0 +1,183 @@
+# tsl2591 lux sensor interface
+import time
+
+VISIBLE = 2
+INFRARED = 1
+FULLSPECTRUM = 0
+
+ADDR = 0x29
+READBIT = 0x01
+COMMAND_BIT = 0xA0
+CLEAR_BIT = 0x40
+WORD_BIT = 0x20
+BLOCK_BIT = 0x10
+ENABLE_POWERON = 0x01
+ENABLE_POWEROFF = 0x00
+ENABLE_AEN = 0x02
+ENABLE_AIEN = 0x10
+CONTROL_RESET = 0x80
+LUX_DF = 408.0
+LUX_COEFB = 1.64
+LUX_COEFC = 0.59
+LUX_COEFD = 0.86
+
+REGISTER_ENABLE = 0x00
+REGISTER_CONTROL = 0x01
+REGISTER_THRESHHOLDL_LOW = 0x02
+REGISTER_THRESHHOLDL_HIGH = 0x03
+REGISTER_THRESHHOLDH_LOW = 0x04
+REGISTER_THRESHHOLDH_HIGH = 0x05
+REGISTER_INTERRUPT = 0x06
+REGISTER_CRC = 0x08
+REGISTER_ID = 0x0A
+REGISTER_CHAN0_LOW = 0x14
+REGISTER_CHAN0_HIGH = 0x15
+REGISTER_CHAN1_LOW = 0x16
+REGISTER_CHAN1_HIGH = 0x17
+INTEGRATIONTIME_100MS = 0x00
+INTEGRATIONTIME_200MS = 0x01
+INTEGRATIONTIME_300MS = 0x02
+INTEGRATIONTIME_400MS = 0x03
+INTEGRATIONTIME_500MS = 0x04
+INTEGRATIONTIME_600MS = 0x05
+
+GAIN_LOW = 0x00
+GAIN_MED = 0x10
+GAIN_HIGH = 0x20
+GAIN_MAX = 0x30
+
+def _bytes_to_int(data):
+    return data[0] + (data[1]<<8)
+
+from machine import I2C, Pin
+class SMBusEmulator:
+    __slots__ = ('i2c',)
+    def __init__(self, scl_pinno=32, sda_pinno=33):
+        self.i2c = I2C(scl=Pin(scl_pinno, Pin.IN),
+                       sda=Pin(sda_pinno, Pin.IN))
+
+    def write_byte_data(self, addr, cmd, val):
+        buf = bytes([cmd, val])
+        self.i2c.writeto(addr, buf)
+
+    def read_word_data(self, addr, cmd):
+        assert cmd < 256
+        buf = bytes([cmd])
+        self.i2c.writeto(addr, buf)
+        data = self.i2c.readfrom(addr, 4)
+        return _bytes_to_int(data)
+
+SENSOR_ADDRESS=0x29
+
+class Tsl2591:
+    def __init__(
+                 self,
+                 sensor_id,
+                 integration=INTEGRATIONTIME_100MS,
+                 gain=GAIN_LOW
+                 ):
+        self.sensor_id = sensor_id
+        self.bus = SMBusEmulator()
+        self.integration_time = integration
+        self.gain = gain
+        self.set_timing(self.integration_time)
+        self.set_gain(self.gain)
+        self.disable()
+
+    def set_timing(self, integration):
+        self.enable()
+        self.integration_time = integration
+        self.bus.write_byte_data(
+                    SENSOR_ADDRESS,
+                    COMMAND_BIT | REGISTER_CONTROL,
+                    self.integration_time | self.gain
+                    )
+        self.disable()
+
+    def set_gain(self, gain):
+        self.enable()
+        self.gain = gain
+        self.bus.write_byte_data(
+                    SENSOR_ADDRESS,
+                    COMMAND_BIT | REGISTER_CONTROL,
+                    self.integration_time | self.gain
+                    )
+        self.disable()
+
+    def calculate_lux(self, full, ir):
+        if (full == 0xFFFF) | (ir == 0xFFFF):
+            return 0
+            
+        case_integ = {
+            INTEGRATIONTIME_100MS: 100.,
+            INTEGRATIONTIME_200MS: 200.,
+            INTEGRATIONTIME_300MS: 300.,
+            INTEGRATIONTIME_400MS: 400.,
+            INTEGRATIONTIME_500MS: 500.,
+            INTEGRATIONTIME_600MS: 600.,
+            }
+        if self.integration_time in case_integ.keys():
+            atime = case_integ[self.integration_time]
+        else:
+            atime = 100.
+
+        case_gain = {
+            GAIN_LOW: 1.,
+            GAIN_MED: 25.,
+            GAIN_HIGH: 428.,
+            GAIN_MAX: 9876.,
+            }
+
+        if self.gain in case_gain.keys():
+            again = case_gain[self.gain]
+        else:
+            again = 1.
+
+        cpl = (atime * again) / LUX_DF
+        lux1 = (full - (LUX_COEFB * ir)) / cpl
+
+        lux2 = ((LUX_COEFC * full) - (LUX_COEFD * ir)) / cpl
+
+        return max([lux1, lux2])
+
+    def enable(self):
+        self.bus.write_byte_data(
+                    SENSOR_ADDRESS,
+                    COMMAND_BIT | REGISTER_ENABLE,
+                    ENABLE_POWERON | ENABLE_AEN | ENABLE_AIEN
+                    )
+
+    def disable(self):
+        self.bus.write_byte_data(
+                    SENSOR_ADDRESS,
+                    COMMAND_BIT | REGISTER_ENABLE,
+                    ENABLE_POWEROFF
+                    )
+
+    def get_full_luminosity(self):
+        self.enable()
+        time.sleep(0.120*self.integration_time+1)
+        full = self.bus.read_word_data(
+                    SENSOR_ADDRESS, COMMAND_BIT | REGISTER_CHAN0_LOW
+                    )
+        ir = self.bus.read_word_data(
+                    SENSOR_ADDRESS, COMMAND_BIT | REGISTER_CHAN1_LOW
+                    )                    
+        self.disable()
+        return full, ir
+
+    def get_luminosity(self, channel):
+        full, ir = self.get_full_luminosity()
+        if channel == FULLSPECTRUM:
+            return full
+        elif channel == INFRARED:
+            return ir
+        elif channel == VISIBLE:
+            return full - ir
+        else:
+            return 0
+
+    def sample(self):
+        full, ir = self.get_full_luminosity()
+        return self.calculate_lux(full, ir)
+