diff --git a/main.py b/main.py
new file mode 100644
index 0000000..154437c
--- /dev/null
+++ b/main.py
@@ -0,0 +1,70 @@
+import uPyConfig
+import init_sample
+
+hw = uPyConfig.esp8266(variant='d1-r2')
+#print family, variant and IP address (using oled, if available on-board)
+init_sample.init_sample(hw)
+
+# Main app
+from uPySensor import LM75A, SHT21
+thsen=SHT21(hw.i2c.bus)
+tsen=LM75A(hw.i2c.bus)
+json={
+    'sht21_t': '{"temperature":"%0.3f"}',
+    'sht21_h': '{"humidity":"%0.3f"}',
+    'sht21':   '{"temperature":"%0.3f","humidity":"%0.3f"}',
+    'lm75a_t': '{"temperature":"%0.1f"}',
+    'lm75a':   '{"temperature":"%0.1f"}',
+}
+json_all='{"sht21":{"temperature":"%0.3f","humidity":"%0.3f"},"lm75a":{"temperature":"%0.1f"}}'
+
+def header():
+    return "HTTP/1.1 200 OK\r\n" \
+           "Content-Type: application/json\r\n" \
+           "Server: horny\r\n" \
+           "\r\n"
+
+def get():
+    return json_all % (thsen.read_tempC(), thsen.read_hum(), tsen.read_tempC())
+
+def get_sht21_t():
+    return json['sht21_t'] % (thsen.read_tempC())
+
+def get_sht21_h():
+    return json['sht21_h'] % (thsen.read_hum())
+
+def get_sht21():
+    return json['sht21'] % (thsen.read_tempC(), thsen.read_hum())
+
+def get_lm75a_t():
+    return json['lm75a_t'] % (tsen.read_tempC())
+
+def get_lm75a():
+    return json['lm75a'] % (tsen.read_tempC())
+
+#begin web
+import socket
+wssock=socket.getaddrinfo("0.0.0.0",80)[0][-1]
+wss=socket.socket()
+wss.bind(wssock)
+wss.listen(1)
+
+print("Server started on 0.0.0.0:80")
+
+#main loop
+while True:
+    wcl, wcsock = wss.accept()
+    print("Client connected")
+    wclfh = wcl.makefile('rwb', 0)
+    jsn=''
+    while True:
+        wcline = wclfh.readline()
+        if not wcline or wcline == b'\r\n': break
+        wcline=wcline.split(b' ')
+        if len(wcline) == 3 and wcline[2].startswith('HTTP'):
+            if wcline[0] != b'GET': wcl.close()
+            elif wcline[1] == b'/': jsn=get()
+            elif wcline[1] == b'/sht21': jsn=get_sht21()
+            elif wcline[1] == b'/lm75a': jsn=get_lm75a()
+    wcl.send(header()+jsn)
+    wcl.close()
diff --git a/ssd1306.py b/ssd1306.py
new file mode 100644
index 0000000..e949137
--- /dev/null
+++ b/ssd1306.py
@@ -0,0 +1,168 @@
+# MicroPython SSD1306 OLED driver, I2C and SPI interfaces
+
+import time
+import framebuf
+
+
+# register definitions
+SET_CONTRAST        = const(0x81)
+SET_ENTIRE_ON       = const(0xa4)
+SET_NORM_INV        = const(0xa6)
+SET_DISP            = const(0xae)
+SET_MEM_ADDR        = const(0x20)
+SET_COL_ADDR        = const(0x21)
+SET_PAGE_ADDR       = const(0x22)
+SET_DISP_START_LINE = const(0x40)
+SET_SEG_REMAP       = const(0xa0)
+SET_MUX_RATIO       = const(0xa8)
+SET_COM_OUT_DIR     = const(0xc0)
+SET_DISP_OFFSET     = const(0xd3)
+SET_COM_PIN_CFG     = const(0xda)
+SET_DISP_CLK_DIV    = const(0xd5)
+SET_PRECHARGE       = const(0xd9)
+SET_VCOM_DESEL      = const(0xdb)
+SET_CHARGE_PUMP     = const(0x8d)
+
+
+class SSD1306:
+    def __init__(self, width, height, external_vcc):
+        self.width = width
+        self.height = height
+        self.external_vcc = external_vcc
+        self.pages = self.height // 8
+        # Note the subclass must initialize self.framebuf to a framebuffer.
+        # This is necessary because the underlying data buffer is different
+        # between I2C and SPI implementations (I2C needs an extra byte).
+        self.poweron()
+        self.init_display()
+
+    def init_display(self):
+        for cmd in (
+            SET_DISP | 0x00, # off
+            # address setting
+            SET_MEM_ADDR, 0x00, # horizontal
+            # resolution and layout
+            SET_DISP_START_LINE | 0x00,
+            SET_SEG_REMAP | 0x01, # column addr 127 mapped to SEG0
+            SET_MUX_RATIO, self.height - 1,
+            SET_COM_OUT_DIR | 0x08, # scan from COM[N] to COM0
+            SET_DISP_OFFSET, 0x00,
+            SET_COM_PIN_CFG, 0x02 if self.height == 32 else 0x12,
+            # timing and driving scheme
+            SET_DISP_CLK_DIV, 0x80,
+            SET_PRECHARGE, 0x22 if self.external_vcc else 0xf1,
+            SET_VCOM_DESEL, 0x30, # 0.83*Vcc
+            # display
+            SET_CONTRAST, 0xff, # maximum
+            SET_ENTIRE_ON, # output follows RAM contents
+            SET_NORM_INV, # not inverted
+            # charge pump
+            SET_CHARGE_PUMP, 0x10 if self.external_vcc else 0x14,
+            SET_DISP | 0x01): # on
+            self.write_cmd(cmd)
+        self.fill(0)
+        self.show()
+
+    def poweroff(self):
+        self.write_cmd(SET_DISP | 0x00)
+
+    def contrast(self, contrast):
+        self.write_cmd(SET_CONTRAST)
+        self.write_cmd(contrast)
+
+    def invert(self, invert):
+        self.write_cmd(SET_NORM_INV | (invert & 1))
+
+    def show(self):
+        x0 = 0
+        x1 = self.width - 1
+        if self.width == 64:
+            # displays with width of 64 pixels are shifted by 32
+            x0 += 32
+            x1 += 32
+        self.write_cmd(SET_COL_ADDR)
+        self.write_cmd(x0)
+        self.write_cmd(x1)
+        self.write_cmd(SET_PAGE_ADDR)
+        self.write_cmd(0)
+        self.write_cmd(self.pages - 1)
+        self.write_framebuf()
+
+    def fill(self, col):
+        self.framebuf.fill(col)
+
+    def pixel(self, x, y, col):
+        self.framebuf.pixel(x, y, col)
+
+    def scroll(self, dx, dy):
+        self.framebuf.scroll(dx, dy)
+
+    def text(self, string, x, y, col=1):
+        self.framebuf.text(string, x, y, col)
+
+
+class SSD1306_I2C(SSD1306):
+    def __init__(self, width, height, i2c, addr=0x3c, external_vcc=False):
+        self.i2c = i2c
+        self.addr = addr
+        self.temp = bytearray(2)
+        # Add an extra byte to the data buffer to hold an I2C data/command byte
+        # to use hardware-compatible I2C transactions.  A memoryview of the
+        # buffer is used to mask this byte from the framebuffer operations
+        # (without a major memory hit as memoryview doesn't copy to a separate
+        # buffer).
+        self.buffer = bytearray(((height // 8) * width) + 1)
+        self.buffer[0] = 0x40  # Set first byte of data buffer to Co=0, D/C=1
+        self.framebuf = framebuf.FrameBuffer1(memoryview(self.buffer)[1:], width, height)
+        super().__init__(width, height, external_vcc)
+
+    def write_cmd(self, cmd):
+        self.temp[0] = 0x80 # Co=1, D/C#=0
+        self.temp[1] = cmd
+        self.i2c.writeto(self.addr, self.temp)
+
+    def write_framebuf(self):
+        # Blast out the frame buffer using a single I2C transaction to support
+        # hardware I2C interfaces.
+        self.i2c.writeto(self.addr, self.buffer)
+
+    def poweron(self):
+        pass
+
+
+class SSD1306_SPI(SSD1306):
+    def __init__(self, width, height, spi, dc, res, cs, external_vcc=False):
+        self.rate = 10 * 1024 * 1024
+        dc.init(dc.OUT, value=0)
+        res.init(res.OUT, value=0)
+        cs.init(cs.OUT, value=1)
+        self.spi = spi
+        self.dc = dc
+        self.res = res
+        self.cs = cs
+        self.buffer = bytearray((height // 8) * width)
+        self.framebuf = framebuf.FrameBuffer1(self.buffer, width, height)
+        super().__init__(width, height, external_vcc)
+
+    def write_cmd(self, cmd):
+        self.spi.init(baudrate=self.rate, polarity=0, phase=0)
+        self.cs.high()
+        self.dc.low()
+        self.cs.low()
+        self.spi.write(bytearray([cmd]))
+        self.cs.high()
+
+    def write_framebuf(self):
+        self.spi.init(baudrate=self.rate, polarity=0, phase=0)
+        self.cs.high()
+        self.dc.high()
+        self.cs.low()
+        self.spi.write(self.buffer)
+        self.cs.high()
+
+    def poweron(self):
+        self.res.high()
+        time.sleep_ms(1)
+        self.res.low()
+        time.sleep_ms(10)
+        self.res.high()
diff --git a/uPyConfig.py b/uPyConfig.py
new file mode 100644
index 0000000..d4aabe4
--- /dev/null
+++ b/uPyConfig.py
@@ -0,0 +1,158 @@
+class uPyConfig:
+    from machine import I2C, Pin
+    class features:
+        class connectivity:
+            wifi = False
+            bluetooth = False
+            bluetooth_le = False
+            lora = False
+
+        class display:
+            oled = False
+
+        class sensor:
+            capacitive = False
+            temperature = False
+            hall_effect = False
+
+    class _i2c:
+        from machine import I2C, Pin
+
+        def load_handle(self):
+            self.bus = self.I2C(scl=self.scl, sda=self.sda)
+            self.bus.init(scl=self.scl, sda=self.sda)
+
+        def __init__(self, scl, sda):
+            self.scl=self.Pin(scl)
+            self.sda=self.Pin(sda)
+            self.load_handle()
+
+    class _oled:
+        from machine import Pin
+        from time import sleep_ms
+        addr = 0x0
+        rst = 0
+        rst_hold = False
+        height = 0
+        width = 0
+
+        def load_handle(self):
+            if self.rst_hold:
+                self.rst = self.Pin(self.rst, self.Pin.OUT)
+                self.rst.value(0)
+                self.sleep_ms(2)
+                self.rst.value(1)
+            from ssd1306 import SSD1306_I2C
+            self.handle = SSD1306_I2C(self.width, self.height, self.i2c.bus)
+
+        def __init__(self, i2c):
+            self.i2c = i2c
+
+    def __init__(self, board_defs):
+        self.i2c = self._i2c(board_defs['i2c_scl'], board_defs['i2c_sda'])
+        if 'has_wifi' in board_defs.keys(): self.features.connectivity.wifi = True
+        if 'has_bluetooth' in board_defs.keys(): self.features.connectivity.bluetooth = True
+        if 'has_bluetooth_le' in board_defs.keys(): self.features.connectivity.bluetooth_le = True
+        if 'sen_capacitive' in board_defs.keys(): self.features.sensor.capacitive = True
+        if 'sen_temperature' in board_defs.keys(): self.features.sensor.temperature = True
+        if 'sen_hall' in board_defs.keys(): self.features.sensor.hall_effect = True
+        if 'has_oled' in board_defs.keys():
+            self.features.display.oled = True
+            self.oled = self._oled(self.i2c)
+            self.oled.addr = board_defs['oled_addr']
+            if 'oled_hold' in board_defs.keys(): self.oled.rst_hold = board_defs['oled_hold']
+            if 'oled_rst' in board_defs.keys(): self.oled.rst = board_defs['oled_rst']
+            self.oled.width = board_defs['oled_width']
+            self.oled.height = board_defs['oled_height']
+            self.oled.load_handle()
+
+class esp8266(uPyConfig):
+    family = 'esp8266'
+
+    defaults = {
+        'has_wifi': True,
+        'i2c_scl': 4,
+        'i2c_sda': 5,
+        'oled_addr': 0x3c,
+    }
+
+    variants = {
+        'generic': {},
+        'lolinv3': {
+            'i2c_scl': 4,
+            'i2c_sda': 5,
+        },
+        'd1-r2': {
+            'i2c_scl': 5,
+            'i2c_sda': 4,
+        },
+        'heltec': {
+            'i2c_scl': 5,
+            'i2c_sda': 4,
+            'oled_rst': 16,
+            'has_oled': True,
+            'oled_hold': True,
+            'oled_height': 32,
+            'oled_width': 128,
+        },
+        'ttgo': {
+            'i2c_scl': 14,
+            'i2c_sda': 2,
+            'oled_rst': 4,
+            'has_oled': True,
+            'oled_hold': True,
+            'oled_height': 32,
+            'oled_width': 128,
+        },
+    }
+
+    def __init__(self, variant='generic'):
+        if variant in self.variants.keys():
+            self.variant = variant
+            defs = self.defaults.copy()
+            defs.update(self.variants[variant])
+            super().__init__(defs)
+        else:
+            raise ValueError("Board variant '%s' is not known" % variant)
+
+class esp32(uPyConfig):
+    family = 'esp32'
+
+    defaults = {
+        'has_wifi': True,
+        'has_bluetooth': True,
+        'has_bluetooth_le': True,
+        'sen_capacitive': True,
+        'sen_temperature': True,
+        'sen_hall': True,
+        'i2c_scl': 4,
+        'i2c_sda': 5,
+        'oled_addr': 0x3c,
+    }
+
+    variants = {
+        'generic': {},
+        'wemos-lolin32': {
+            'has_oled': True,
+            'oled_height': 64,
+            'oled_width': 128,
+        },
+        'heltec': {
+            'i2c_scl': 15,
+            'i2c_sda': 4,
+            'oled_rst': 16,
+            'has_oled': True,
+            'oled_hold': True,
+            'oled_height': 64,
+            'oled_width': 128,
+        },
+    }
+
+    def __init__(self, variant='generic'):
+        if variant in self.variants.keys():
+            self.variant = variant
+            defs = self.defaults.copy()
+            defs.update(self.variants[variant])
+            super().__init__(defs)
+        else:
+            raise ValueError("Board variant '%s' is not known" % variant)
diff --git a/uPySensor.py b/uPySensor.py
new file mode 100644
index 0000000..6b921de
--- /dev/null
+++ b/uPySensor.py
@@ -0,0 +1,80 @@
+class uPySensor:
+    def __init__(self):
+        dummy=''
+
+    def sleep_ms(self, delay):
+        from time import sleep_ms
+        sleep_ms(delay)
+
+
+class LM75A(uPySensor):
+    LM75A_ADDRESS = 0x48
+
+    def __init__(self, i2c):
+        self.i2c = i2c
+
+    def readbyte(self):
+        return self.i2c.readfrom(self.LM75A_ADDRESS, 1)
+
+    def readbytes(self, num):
+        return self.i2c.readfrom(self.LM75A_ADDRESS, num)
+
+    def read_tempC(self):
+        import math
+        data = self.readbytes(2)
+        return float("%d.%d" % (int(data[0]), math.floor(int(data[1])/23)))
+
+class SHT21(uPySensor):
+    SOFT_RESET = 0xfe
+    SHT21_ADDRESS = 0x40
+    TRIG_TEMP_NO_HOLD = 0xf3
+    TRIG_HUM_NO_HOLD = 0xf5
+
+    def writebyte(self, byte):
+        self.i2c.writeto(self.SHT21_ADDRESS, bytearray([byte]))
+
+    def readbyte(self):
+        return self.i2c.readfrom(self.SHT21_ADDRESS, 1)
+
+    def readbytes(self, num):
+        return self.i2c.readfrom(self.SHT21_ADDRESS, num)
+
+    def __init__(self, i2c):
+        self.i2c = i2c
+        self.writebyte(self.SOFT_RESET)
+        self.sleep_ms(15)
+
+    def read_tempC(self):
+        self.writebyte(self.TRIG_TEMP_NO_HOLD)
+        self.sleep_ms(250)
+        data = self.readbytes(2)
+        return self._buffer_to_tempC(data)
+
+    def read_hum(self):
+        self.writebyte(self.TRIG_HUM_NO_HOLD)
+        self.sleep_ms(250)
+        data = self.readbytes(2)
+        return self._buffer_to_hum(data)
+
+    def _buffer_to_tempC(self, buf):
+        unadj = (buf[0] << 8) + buf[1]
+        unadj *= 175.72
+        unadj /= 1 << 16
+        unadj -= 46.85
+        return unadj
+
+    def _buffer_to_hum(self, buf):
+        unadj = (buf[0] << 8) + buf[1]
+        unadj *= 125
+        unadj /= 1 << 16
+        unadj -= 6
+        return unadj
+
+    def close(self):
+        self.i2c.close()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, type, value, traceback):
+        self.close()
diff --git a/webrepl_cfg.py b/webrepl_cfg.py
new file mode 100644
index 0000000..5c0b724
--- /dev/null
+++ b/webrepl_cfg.py
@@ -0,0 +1 @@
+PASS='WebREPLPassword'
\ No newline at end of file