Documentation/pycardium/overview.rst

@@ -33,11 +33,56 @@ systems this device will be called ``/dev/ttyACM0`` or ``/dev/ttyACM1``.
 Choose a terminal-emulator of your liking and open the above mentioned device.
 Baud-rate is 115200.  Some options are:
 
-* **screen**: ``screen /dev/ttyACM0 115200``
-* **picocom**: ``picocom -b 115200 /dev/ttyACM0``
+* **screen**: ``sudo screen /dev/ttyACM0 115200``
+* **picocom**: ``sudo picocom -b 115200 /dev/ttyACM0``
 
-After connecting, reboot card10 and you should see the MicroPython REPL pop up.
+After connecting, reboot reset the card10 via the power button (left upper
+corner) and you should see the output of **menu.py** script (it's located in
+*preload/menu.py*). You can press CTRL-C to interrupt the script and jump into
+the MicroPython prompt.
 
-.. todo::
+To switch on the blue fairy dust you must import the led python module::
 
-   Getting Started Guide for people interested in writing Python code.
+   import leds
+
+and power it on::
+
+   leds.set_rocket(0, 31)
+
+.. note::
+
+   If you're using iOS/Mac then you can connect to your serial console using:
+
+   .. code-block:: shell-session
+
+      screen /dev/tty.usbmodem* 115200
+
+   You can now see in your console what buttons you have pressed and your
+   console outputs/logs.  With ``CTRL+C`` you exit the console.
+
+REPL modes
+^^^^^^^^^^
+MicroPython supports a different REPL modes over the serial console. The modes
+can be changed on every new line.
+
+Normal mode
+"""""""""""
+This is the mode you will first see. You can switch to it by pressing CTRL-B.
+If you are in a other mode you can return to this mode by pressing CTRL-B too.
+
+Paste mode
+""""""""""
+You can enter the paste mode by pressing CTRL-E and you can simple copy 'n'
+paste your source code into the console and it will be interpreted and executed
+line by line. Every new line will be reply by the prompt with **===**.
+
+RAW mode
+""""""""
+The RAW mode to be intendend for the usage with tools. By pressing CTRL-A you
+will enter the RAW REPL mode. The type in code will not printed. By pressing
+CTRL-D the whole entered code will be evaluated and executed. The board will
+reply with **OK** and print after that the output (print commands) of the code
+or give you tracebacks if an error occured.
+
+You can use **pycard10** (tools/pycard10.py) to execute python files from your
+PC directly on the card10.

Documentation/pycardium/personal_state.rst

@@ -2,7 +2,12 @@
 
 ``personal_state`` - Personal State
 ===================================
-The :py:mod:`personal_state` module allows you to set and get the card10 users personal state from your script. The personal state is displayed on the top-left LED on the bottom of the harmonics board. While the personal state is set the LED can't be controlled by the :py:mod:`leds` module.
+The :py:mod:`personal_state` module allows you to set and get the card10 users
+`personal state`_ from your script. The personal state is displayed on the
+top-left LED on the bottom of the harmonics board. While the personal state is
+set the LED can't be controlled by the :py:mod:`leds` module.
+
+.. _personal state: https://card10.badge.events.ccc.de/ps/
 
 **Example**:
 
@@ -26,8 +31,13 @@ The :py:mod:`personal_state` module allows you to set and get the card10 users p
 
    Set the users personal state.
 
-   :param int state: ID of the personal state to set. Must be one of :py:data:`personal_state.NO_CONTACT`, :py:data:`personal_state.CHAOS`, :py:data:`personal_state.COMMUNICATION`, :py:data:`personal_state.CAMP`.
-   :param int persistent: Controls whether the personal state is persistent. A persistent state is not reset when the pycardium application is changed or restarted. In persistent mode the personal state LED is not controllable by the pycardium application.
+   :param int state: ID of the personal state to set. Must be one of
+      :py:data:`personal_state.NO_CONTACT`, :py:data:`personal_state.CHAOS`,
+      :py:data:`personal_state.COMMUNICATION`, :py:data:`personal_state.CAMP`.
+   :param int persistent: Controls whether the personal state is persistent. A
+      persistent state is not reset when the pycardium application is changed
+      or restarted. In persistent mode the personal state LED is not
+      controllable by the pycardium application.
 
 .. py:function:: clear()
 
@@ -40,7 +50,8 @@ The :py:mod:`personal_state` module allows you to set and get the card10 users p
 
    Get the users personal state.
 
-   :returns: A tuple containing the currently set state and a boolean indicating if it's persistent or not.
+   :returns: A tuple containing the currently set state and a boolean
+      indicating if it's persistent or not.
 
 .. py:data:: NO_STATE
 

Documentation/pycardium/png.rst

+``png`` - PNG Decoder
+=====================
+The ``png`` module provides functions to decode PNG files into raw pixel data
+which can be displayed using the card10's display or its LEDs.
+
+.. automodule:: png
+   :members:

Documentation/pycardium/power.rst

+.. py:module:: power
+
+``power`` - PMIC power module handling
+======================================
+.. versionadded:: 1.4
+
+The :py:mod:`power` module allows you to read the card10's power status
+in your scripts.
+
+**Example**:
+
+.. code-block:: python
+
+   import power
+
+   print(power.read_battery_voltage())
+
+.. py:function:: read_battery_voltage()
+
+   Read the battery voltage in V.  Please keep in mind that battery
+   voltage behaves exponentially when interpreting this value.
+
+   .. warning::
+
+      Card10 will hard-shutdown once the voltage drops below 3.4 V
+
+   .. versionadded:: 1.4
+
+.. py:function:: read_battery_current()
+
+   Read the battery-side current flow in A.
+
+   .. versionadded:: 1.4
+
+.. py:function:: read_chargein_voltage()
+
+   Read the charge voltage in V.
+
+   .. versionadded:: 1.4
+
+.. py:function:: read_chargein_current()
+
+   Read the charge current in A.
+
+   .. versionadded:: 1.4
+
+.. py:function:: read_system_voltage()
+
+   Read the system-side voltate in V.
+
+   .. versionadded:: 1.4
+
+.. py:function:: read_thermistor_voltage()
+
+   Read the thermistor voltage in V.
+
+   There is a resistor network from GND over a thermistor
+   (10K at room temperature) over 10K to the Thermistor Bias voltage.
+   This reads the voltage between thermistor and resistor.
+
+   .. versionadded:: 1.4

Documentation/pycardium/simple_menu.rst

+``simple_menu`` - Draw a Menu
+=============================
+.. versionadded:: 1.4
+
+To allow quickly hacking some scripts, Pycardium has a small library for
+displaying menus.  You can use it like this:
+
+.. code-block:: python
+
+   import color
+   import simple_menu
+
+
+   class MyMenu(simple_menu.Menu):
+       color_1 = color.CAMPGREEN
+       color_2 = color.CAMPGREEN_DARK
+
+       def on_select(self, name, index):
+           print("{!r} was selected!".format(name))
+
+
+   if __name__ == "__main__":
+       MyMenu(["foo", "bar", "baz"]).run()
+
+.. autoclass:: simple_menu.Menu
+   :members:
+
+.. autodata:: simple_menu.TIMEOUT
+
+.. autofunction:: simple_menu.button_events

Documentation/pycardium/stdlib.rst

 MicroPython Standard Library
 ============================
-Pycardium contains some modules from the MicroPython standard library.  These
-are:
+Pycardium contains some modules from the MicroPython standard library.
+
+Some modules below use a standard Python name, but prefixed with “u”,
+e.g. ujson instead of json. This is to signify that such a module is a
+micro-library, i.e. implements only a subset of CPython module
+functionality. Please refer to the official `MicroPython docs`_ for an
+explanation why.
+
+All u-name modules can also be imported using their non-u-name. E.g.
+``import utime`` and import ``import time`` will both work.
+
+.. _MicroPython docs: http://docs.micropython.org/en/latest/library/index.html#python-standard-libraries-and-micro-libraries
+
+.. py:module:: framebuf
+
+``framebuf``
+------------
+Refer to the official `MicroPython docs for framebuf`_.
+
+.. _MicroPython docs for framebuf: https://docs.micropython.org/en/latest/library/framebuf.html
 
 .. py:module:: ubinascii
 
@@ -201,6 +219,8 @@ Struct module.
       UUID(bytes='\x12\x34\x56\x78' * 4)
       UUID(int=0x12345678123456781234567812345678)
 
+   .. versionadded:: 1.10
+
    .. py:attribute:: bytes
 
       UUID as ``bytes()`` object
@@ -217,11 +237,8 @@ Struct module.
 
       UUID version accordiung to RFC 4122
 
-.. py:function:: uuid4():
+.. py:function:: uuid4()
 
    Generate a new UUID version 4 (random UUID).
 
-   .. todo::
-
-      This function is not yet usable because we don't have
-      :py:func:`os.urandom` yet.
+   .. versionadded:: 1.10

Documentation/pycardium/utime.rst

@@ -8,6 +8,9 @@ CPython but wouldn't fit anywhere else in our implementation.  Most
 prominently,  this is the :py:func:`utime.alarm` function for setting an RTC
 alarm.
 
+Like all other u-name modules, ``utime`` can also imported using the standard
+``import time`` statement.
+
 .. |time| replace:: ``time``
 .. _time: https://docs.python.org/3/library/time.html
 
@@ -28,11 +31,69 @@ alarm.
    Return the current timestamp in seconds since 2000-01-01 00:00 in
    the local timezone.
 
+.. py:function:: time_ms()
+
+   Return the current timestamp in milliseconds since 2000-01-01 00:00 in
+   the local timezone.
+
+.. py:function:: monotonic()
+
+   Return a monotonically increasing timestamp.
+
+   .. versionadded:: 1.11
+
+.. py:function:: monotonic_ms()
+
+   Return a monotonically increasing timestamp in milliseconds.
+
+   .. versionadded:: 1.11
+
+.. py:function:: ticks_ms()
+
+   Return processor ticks (converted to milliseconds) since Pycardium startup.
+
+   This function should be the preferred method for timing and profiling
+   because it does not need an API call and thus is very fast.
+
+   .. versionadded:: 1.13
+
+.. py:function:: ticks_us()
+
+   Return processor ticks (converted to microseconds) since Pycardium startup.
+
+   This function should be the preferred method for timing and profiling
+   because it does not need an API call and thus is very fast.
+
+   .. versionadded:: 1.13
+
+.. py:function:: unix_time()
+
+   Return the current unix time as seconds since the epoch.
+
+   .. versionadded:: 1.12
+
+.. py:function:: unix_time_ms()
+
+   Return the current unix time as milliseconds since the epoch.
+
+   .. versionadded:: 1.12
+
 .. py:function:: set_time(secs)
 
    Sets the time to ``secs`` seconds since 2000-01-01 00:00 in the local
    timezone.
-   
+
+   .. versionchanged:: 1.4
+      :py:func:`utime.set_time` previously applied a wrong timezone offset,
+      thus leading to wrong results.
+
+.. py:function:: set_time_ms(msecs)
+
+   Set the time to ``msecs`` seconds since 2000-01-01 00:00 in the local
+   timezone.
+
+   .. versionadded:: 1.12
+
 .. py:function:: set_unix_time(secs)
 
    Sets the time to ``secs`` seconds since 1970-01-01 00:00 UTC.
@@ -40,6 +101,12 @@ alarm.
    by running ``date +%s`` in a command line or ``int(time.time())``
    in Python.
 
+.. py:function:: set_unix_time_ms(msecs)
+
+   Set the time to ``msecs`` milliseconds since the unix epoch.
+
+   .. versionadded:: 1.12
+
 .. py:function:: localtime([secs])
 
    Return the current time as a timestruct tuple.  If ``secs`` is given, return
@@ -71,13 +138,13 @@ alarm.
 
    .. code-block:: python
 
-      import utime
+      import time
 
       def minute_timer(x):
-         current = utime.time()
+         current = time.time()
          print("Current: " + str(current))
          alarm = (current // 60 + 1) * 60
-         utime.alarm(alarm, minute_timer)
+         time.alarm(alarm, minute_timer)
 
       minute_timer(None)
 
@@ -86,13 +153,13 @@ alarm.
 
    .. code-block:: python
 
-      import interrupt, utime
+      import interrupt, time
 
       def 5_second_timer(x):
-         current = utime.time()
+         current = time.time()
          print("Current: " + str(current))
          alarm = (current // 10) * 10 + 5
-         utime.alarm(alarm)
+         time.alarm(alarm)
 
       # This time, we need to register and enable the callback manually
       interrupt.set_callback(interrupt.RTC_ALARM, 5_second_timer)

Documentation/pycardium/ws2812.rst

+.. py:module:: ws2812
+
+``ws2812`` - Neopixel LEDs
+==========================
+The ``ws2812`` module controls LEDs of the WS2812 type. Just as the ``leds`` module, it exposes a function :py:func:`ws2812.set_all`, which works a similar fashion.
+
+.. versionadded:: 1.10
+
+.. py:function:: set_all(pin, colors)
+
+   Set multiple of the LEDs to RGB values.
+
+   Filling starts at the LED connected to the specified gpio pin.
+
+   :param int pin: ID of the pin to use for sending the data.
+   :param colors: List of RGB triplets.
+
+   **Example**
+
+   .. code-block:: python
+
+      import color, time, ws2812, gpio
+
+      gpio.set_mode(gpio.WRISTBAND_2, gpio.mode.OUTPUT)
+
+      i = 0
+      while True:
+          col1 = color.from_hsv(i % 360, 1.0, 0.1)
+          col2 = color.from_hsv((i + 20) % 360, 1.0, 0.1)
+          col3 = color.from_hsv((i + 40) % 360, 1.0, 0.1)
+          ws2812.set_all(gpio.WRISTBAND_2, [col1, col2, col3])
+          i += 1
+          time.sleep_ms(10)
+
+   .. versionadded:: 1.10

Documentation/usb-file-transfer.rst

+.. _usb_file_transfer:
+
+USB File Transfer
+=================
+
+The card10 badge bootloader offers a USB Mass Storage mode to access its 8MB external flash.
+
+This flash contains a FAT32 filesystem and files on it will be visible to software running on the badge.
+
+Getting to the USB mode
+-----------------------
+
+To get to the USB mode, you will need to boot the badge while keeping the bottom-right button pressed.
+
+.. image:: static/bootloader-buttons.png
+
+1. If the badge is on, hold the top-left (power) button until the sleep screen appears, then release.
+2. Start holding the bottom-right button.
+3. Quickly press and release the top-left (power) button to turn the badge on.
+4. Your badge should now be in file transfer mode, and you can then release the bottom-right button.
+
+If you succesfully got into USB File Transfer mode, the screen will display its version and notify about the USB mode by displaying ``USB activated. Ready.``. If you connect the badge via USB to your computer, it should now detect 8MB of flash storage that you can mount in the same way as a pendrive.
+
+This pendrive can contain multiple files with different functions, some of them outlined here:
+
+============== ========
+File name      Function
+============== ========
+``card10.bin`` Firmware update file for the badge. If this file is present, the bootloader will perform an internal update to boot from this firmware file, then it will be deleted.
+``main.py``    This file contains the default `application` to be run on power on.
+``menu.py``    This file contains the default `menu` to be run when the power button is short-pressed.
+``*.py``       These are application files written in (Micro)Python that can be run from the menu.
+``*.elf``      These are :ref:`l0dables` that can be run from the menu.
+============== ========
+
+Updating files and rebooting
+----------------------------
+
+No matter which file you are writing, the bootloader will display a red ``Writing`` status message while write operations are pending. Please wait until it displays ``Ready`` again before resetting the badge by pressing the power button again.
+

bootloader/bootloader-display.c

@@ -6,31 +6,17 @@
 #include "gfx.h"
 #include "display.h"
 
-/*
- * "Decompress" splash-screen image.  The algorithm works as follows:
- *
- * Each byte encodes up to 127 pixels in either white or black.  The most
- * significant bit determines the color, the remaining 7 bits determine the
- * amount.
- */
 static void bootloader_display_splash(void)
 {
-	int idx = 0;
-
-	Color white = gfx_color(&display_screen, WHITE);
-	Color black = gfx_color(&display_screen, BLACK);
-	for (int i = 0; i < sizeof(splash); i++) {
-		Color color    = (splash[i] & 0x80) ? white : black;
-		uint8_t length = splash[i] & 0x7f;
-
-		for (int j = 0; j < length; j++) {
-			uint16_t x = idx % 160;
-			uint16_t y = idx / 160;
-			gfx_setpixel(&display_screen, x, y, color);
-			idx++;
-		}
-	}
-
+	gfx_copy_region_rle_mono(
+		&display_screen,
+		0,
+		0,
+		160,
+		80,
+		sizeof(splash),
+		(const void *)(splash)
+	);
 	gfx_update(&display_screen);
 }
 
@@ -55,6 +41,21 @@ void bootloader_display_header(void)
 	bootloader_display_line(2, CARD10_VERSION, white);
 }
 
+void bootloader_display_error(char *errtype, char *line1, char *line2)
+{
+	gfx_clear(&display_screen);
+
+	Color red    = gfx_color(&display_screen, RED);
+	Color yellow = gfx_color(&display_screen, YELLOW);
+	Color white  = gfx_color(&display_screen, WHITE);
+
+	bootloader_display_line(0, "[FATAL ERROR]", red);
+	bootloader_display_line(1, errtype, yellow);
+	bootloader_display_line(2, CARD10_VERSION, white);
+	bootloader_display_line(3, line1, white);
+	bootloader_display_line(4, line2, white);
+}
+
 /*
  * Display a line of text on the display.
  */

bootloader/bootloader.h

@@ -5,6 +5,7 @@
 /* Display */
 void bootloader_display_init(void);
 void bootloader_display_header(void);
+void bootloader_display_error(char *errtype, char *line1, char *line2);
 void bootloader_display_line(int line, char *string, uint16_t color);
 
 /* USB */

bootloader/build_multi_image.sh

@@ -6,8 +6,12 @@ BIN1="$2"
 BIN2="$3"
 BINOUT="$4"
 
-dd if=/dev/zero ibs=1k count=448 2>/dev/null | LANG=C LC_CTYPE=C tr "\000" "\377" > "$BINOUT"
-dd if="$BIN1" of="$BINOUT" conv=notrunc 2>/dev/null
-dd if="$BIN2" >> "$BINOUT" 2>/dev/null
+if [ "$(stat -c "%s" "${BIN1}")" -gt 589824 ]; then
+    echo "$0: ${BIN1} is too big to fit!" >&2
+    exit 1
+fi
+
+objcopy -I binary -O binary --pad-to=589824 --gap-fill=255 "${BIN1}" "$BINOUT"
+cat "$BIN2" >>"$BINOUT"
 
 "$PYTHON" "$(dirname "$0")/crc_patch.py" "$BINOUT"

bootloader/crc_patch.py

 #!/usr/bin/env python3
 import sys
-import crc16
+import warnings
+
+warnings.simplefilter("ignore")
+
+try:
+    import crc16
+
+    crcfun = crc16.crc16xmodem
+except ImportError:
+    try:
+        import crcmod
+
+        crcfun = crcmod.predefined.mkCrcFun("xmodem")
+    except ImportError:
+        try:
+            import crcelk
+
+            crcfun = crcelk.CRC_XMODEM.calc_bytes
+        except ImportError:
+            raise Exception(
+                "Could not find a CRC implementation. Tried: crc16, crcmod, crcelk."
+            )
 
 
 def main():
-    data = open(sys.argv[1], 'rb').read()
-    crc = crc16.crc16xmodem(data)
+    data = open(sys.argv[1], "rb").read()
+    crc = crcfun(data)
     # print(crc)
 
     padded = data + bytes([crc >> 8, crc & 0xFF])
 
-    crc = crc16.crc16xmodem(padded)
+    crc = crcfun(padded)
     # print(crc)
 
-    open(sys.argv[1], 'wb').write(padded)
+    open(sys.argv[1], "wb").write(padded)
 
 
 if __name__ == "__main__":

bootloader/main.c

@@ -179,6 +179,9 @@ void flash_partition(void)
 				data); /* wild cast. not sure if this works */
 		if (ret != E_NO_ERROR) {
 			printf("FLC_Write failed with %d\n", ret);
+			bootloader_display_error(
+				"Firmware Write", "Firmware not", "updated."
+			);
 			while (1)
 				;
 		}

bootstrap.sh

@@ -4,7 +4,9 @@ set -xe
 cd "$(dirname "$0")"
 test -d build/ && rm -r build/
 
-git submodule update --init ./lib/micropython
+# Get external libs (MicroPython, tiny-AES-c, SHA256)
+git submodule deinit --all
+git submodule update --init ./lib
 meson --cross-file card10-cross.ini build/ "$@"
 
 set +x

card10-cross.ini

@@ -6,7 +6,7 @@ strip = 'arm-none-eabi-strip'
 [properties]
 c_args      = ['-mthumb', '-mcpu=cortex-m4', '-mfloat-abi=softfp', '-mfpu=fpv4-sp-d16', '-Wa,-mimplicit-it=thumb', '-ffunction-sections', '-fdata-sections', '-fsingle-precision-constant', '-fno-isolate-erroneous-paths-dereference']
 
-c_link_args = ['-mthumb', '-mcpu=cortex-m4', '-mfloat-abi=softfp', '-mfpu=fpv4-sp-d16', '-Wl,--start-group', '-lc', '-lnosys', '-Wl,--end-group', '--specs=nano.specs']
+c_link_args = ['-mthumb', '-mcpu=cortex-m4', '-mfloat-abi=softfp', '-mfpu=fpv4-sp-d16', '-Wl,--start-group', '-lc', '-lnosys', '-Wl,--end-group', '--specs=nano.specs', '-Wl,-wrap,BbBleDrvRand']
 
 target_defs = ['-DTARGET=32665', '-DTARGET_REV=0x4131', '-DBOARD_CARD10=1']
 

default.nix

@@ -18,6 +18,7 @@ in stdenv.mkDerivation rec {
     bash
     crc16
     gcc-arm-embedded
+    git
     meson
     ninja
     py
@@ -42,10 +43,13 @@ in stdenv.mkDerivation rec {
     meson --cross-file card10-cross.ini "$build"
     ninja -C "$build" -j $NIX_BUILD_CORES
 
-    # Copy artifacts to derivation outputs.
-    install -D -m 444 "$build/bootloader/bootloader.elf" -t "$out/bootloader"
-    install -D -m 444 "$build/pycardium/pycardium_epicardium.bin" -t "$out/pycardium"
-    install -D -m 444 "$build/epicardium/epicardium.elf" -t "$out/epicardium"
-    install -D -m 444 "$build/pycardium/pycardium.elf" -t "$out/pycardium"
+    # Copy ELFs for debugging
+    install -D -m 444 "$build/bootloader/bootloader.elf" -t "$out/lib/bootloader.elf"
+    install -D -m 444 "$build/epicardium/epicardium.elf" -t "$out/lib/epicardium.elf"
+    install -D -m 444 "$build/pycardium/pycardium.elf" -t "$out/lib/pycardium.elf"
+    # Create new flash contents
+    install -D -m 444 "$build/pycardium/pycardium_epicardium.bin" "$out/card10/card10.bin"
+    install -m 444 preload/*.py -t $out/card10/
+    cp -ar preload/apps $out/card10/
   '';
 }

demos/ble-ws2812-card10.py

+import ws2812, gpio, bluetooth, time, display
+from micropython import const
+
+_IRQ_GATTS_WRITE = const(3)
+
+WS2812_SERVICE_UUID = \
+    bluetooth.UUID("23238000-2342-2342-2342-234223422342")
+SET_ALL = (
+    bluetooth.UUID("23238001-2342-2342-2342-234223422342"),
+    bluetooth.FLAG_WRITE
+)
+WS2812_SERVICE = (
+    WS2812_SERVICE_UUID,
+    (SET_ALL,)
+)
+
+def irq(event, data):
+    if event == _IRQ_GATTS_WRITE:
+        conn_handle, value_handle = data
+        value = ble.gatts_read(value_handle)
+        ws2812.set_all(gpio.WRISTBAND_3, [value] * 3)
+
+if __name__ == "__main__":
+    display.open().backlight(0)
+    gpio.set_mode(gpio.WRISTBAND_3, gpio.mode.OUTPUT)
+
+    ble = bluetooth.BLE()
+    ble.active(True)
+    ble.irq(irq)
+    ble.gatts_register_services((WS2812_SERVICE,))
+
+    print("Waiting for connection!")
+
+    while True:
+        time.sleep(1)

demos/ble-ws2812-host.py

+#!/usr/bin/env python3
+import bluepy
+import time
+import colorsys
+
+
+# Change this to the MAC of your card10
+p = bluepy.btle.Peripheral("CA:4D:10:01:ff:64")
+c = p.getCharacteristics(
+    uuid='23238001-2342-2342-2342-234223422342')[0]
+
+hue = 0
+while 1:
+    r,g,b = colorsys.hsv_to_rgb(hue, 1, 0.1)
+    c.write(b"%c%c%c" %
+        (int(r*255), int(g*255), int(b*255)), True)
+    time.sleep(.1)
+    hue += 0.1
+