Minor changes to ePaper files and docs.

DRIVERS.md

@@ -34,7 +34,7 @@ a bare minimum of functionality required to support the above.
        6.4.1 [Micropower applications](./DRIVERS.md#641-micropower-applications)  
   6.5 [Resources](./DRIVERS.md#65-resources)  
  7. [ePaper displays](./DRIVERS.md#7-epaper-displays)  
-  7.1 [Adafruit flexible eInk Display](./DRIVERS.md#71-adafruit-flexible-eink-display)  
+  7.1 [Adafruit monochrome eInk Displays](./DRIVERS.md#71-adafruit-monochrome-eink-displays)  
        7.1.1 [EPD constructor args](./DRIVERS.md#711-epd-constructor-args)  
        7.1.2 [EPD public methods](./DRIVERS.md#712-epd-public-methods)  
        7.1.3 [EPD public bound variables](./DRIVERS.md#713-epd-public-bound-variables)  
@@ -538,9 +538,9 @@ more - which may be problematic for applications which need to respond to
 external events. A specific asynchronous mode provides support for reducing
 blocking time. See [EPD Asynchronous support](./DRIVERS.md#8-epd-asynchronous-support).
 
-## 7.1 Adafruit flexible eInk Display
+## 7.1 Adafruit monochrome eInk Displays
 
-The driver assumes an Adafruit 2.9 inch 296*128 pixel flexible
+The driver supports two Adafruit 2.9 inch 296*128 pixel units. A flexible
 [display](https://www.adafruit.com/product/4262) interfaced via their
 [interface breakout](https://www.adafruit.com/product/4224).
 
@@ -548,28 +548,32 @@ An alternative is the
 [Adafruit 2.9" eInk FeatherWing](https://www.adafruit.com/product/4777) with
 [wiring details](./DRIVERS.md#714-featherwing-wiring) listed below.
 
-These alternatives behave identically except that the FeatherWing shows a black
+In my testing there are differences between these alternatives. The FeatherWing
-border around the display. The reason for this is 
+shows a black border around the display. The reason for this is 
 [unclear](https://github.com/adafruit/Adafruit_CircuitPython_IL0373/issues/11#issuecomment-763704622).
+Secondly, while the FeatherWing behaves as expected the image on the flexible
+display gradually degrades if the display is powered down. The white background
+becomes speckled over a period of a few minutes.
 
-The breakout has an `ENA` pin which enables the display to be powered down.
+The interface breakout for the flexible display has an `ENA` pin which enables
-This facilitates micropower applications: the host shuts down the display
+the display to be powered down. This facilitates micropower applications: the
-before going into deep sleep.
+host shuts down the display before itself going into deep sleep.
 
 The driver is cross platform and supports landscape or portrait mode. To keep
 the buffer size down (to 4736 bytes) there is no greyscale support. It should
-be noted that the Adafruit site cautions against refreshing these displays more
+be noted that the Adafruit site cautions against refreshing the flexible
-frequently than every 180s. It is
+displays more frequently than every 180s. This warning does not appear on the
+FeatherWing pages. No reason for the warning is given and it is
 [unclear](https://forums.adafruit.com/viewtopic.php?f=19&t=174091) if this is
 an absolute limit or an average rate.
 
 ##### Wiring
 
 The [interface schematic is here](https://learn.adafruit.com/assets/86038). The
-drawing title is confusing but I balieve this is the correct schematic.
+drawing title is confusing but I believe this is the correct schematic.
 
 The following assumes a Pyboard host. Pyboard pin numbers are based on hardware
-SPI 2 and my arbitrary choice of GPIO. All may be changed and soft SPI may be
+SPI 2 and an arbitrary choice of GPIO. All may be changed and soft SPI may be
 used.
 
 | Pyb |  Breakout |
@@ -677,7 +681,7 @@ This 2.7" 176*274 display is designed for the Raspberry Pi and is detailed
 I bought two of these units from different sources. Both have hardware issues
 discussed [here](https://forum.micropython.org/viewtopic.php?f=2&t=9564). I
 have failed to achieve consistent behaviour. Units behave perfectly one day and
-fail the next. I published this driver on the assumption that I was sold
+fail the next. I published this driver on the assumption that I was twice sold
 dubious Chinese clones and that genuine ones would be reliable.
 
 The driver is cross-platform.

FPLOT.md

@@ -45,7 +45,7 @@ two varying vectors.
    4.2.1 [Scaling](./FPLOT.md#421-scaling) Required scaling of complex points.  
   4.3 [class TSequence](./FPLOT.md#43-class-tsequence) Plot Y values on time axis.  
 
-###### [Main README](../README.md)
+###### [Main README](./README.md)
 
 # 1. Python files
 
@@ -170,7 +170,7 @@ The Cartesian curve constructor takes the following positional arguments:
 
 Mandatory arguments:
  1. `graph` The `CartesianGraph` instance.
- 2. `color`
+ 2. `color` If `None` is passed, the `graph` foreground color is used.
 
 Optional arguments:  
  3. `populate=None` A generator to populate the curve. See below.   

README.md

@@ -33,6 +33,9 @@ floats as the notionally very long scale moves behind its small window.
 ![Image](images/textbox1.JPG) The Textbox widget for scrolling text with word
 wrap or clipping.
 
+![Image](images/seismo.JPG) A mockup of a seismograph screen on an ePaper
+display.
+
 Notes on [Adafruit and other OLED displays](./ADAFRUIT.md) including
 wiring details, pin names and hardware issues.
 
@@ -258,7 +261,8 @@ Demos for larger displays.
 
 Demos for ePaper displays:  
  * `waveshare_test.py` For the Waveshare eInk Display HAT 2.7" 176*274 display.
- * `epd29_test.py` Demo for Adafruit 2.9" eInk display.
+ * `epd29_sync.py` Demo for Adafruit 2.9" eInk display: emulates a seismograph.
+ * `epd29_async.py` Asynchronous demo for Adafruit 2.9" eInk display.
 
 Demos for Sharp displays:  
  * `sharptest.py` Basic functionality check.
@@ -311,7 +315,8 @@ copied to the hardware root as `color_setup.py`. Example files:
  [Adafruit 1.44 inch TFT display](https://www.adafruit.com/product/2088).
  * `ili9341_setup.py` A 240*320 ILI9341 display on ESP32.
  * `waveshare_setup.py` 176*274 ePaper display.
- * `epd96_asyn.py` Adafruit 2.9 inch ePaper display, optimised for `uasyncio`.
+ * `epd29_sync.py` Adafruit 2.9 inch ePaper display for synchronous code.
+ * `epd29_async.py` Adafruit 2.9 inch ePaper display: `uasyncio` applications.
 
 ## 2.2 Dependencies
 

color_setup/epd29_async.py

@@ -1,5 +1,5 @@
-# epd96_asyn.py Config for asynchronous applications on 2.9" ePaper.
+# epd29_async.py Config for asynchronous applications on 2.9" ePaper.
-# Customise for your hardware config
+# Customise for your hardware config.
 
 # Released under the MIT License (MIT). See LICENSE.
 # Copyright (c) 2020 Peter Hinch

color_setup/epd29_sync.py

@@ -1,7 +1,5 @@
-# epd96_demo.py Allow standard demos to run on ePaper.
+# epd29_sync.py Config for synchronous applications on 2.9" ePaper.
-# Customise for your hardware config.
+# Customise for your hardware config
-# Beware of running demos for long as they refresh the display more frequently
-# than is advised by Adafruit.
 
 # Released under the MIT License (MIT). See LICENSE.
 # Copyright (c) 2020 Peter Hinch
@@ -41,4 +39,4 @@ pbusy = machine.Pin('Y4', machine.Pin.IN)
 spi = machine.SPI(2, baudrate=5_000_000)
 gc.collect()  # Precaution before instantiating framebuf
 ssd = SSD(spi, pcs, pdc, prst, pbusy)  # Create a display instance
-ssd.demo_mode = True
+# ssd.demo_mode = True

gui/core/fplot.py

@@ -58,7 +58,7 @@ class Curve():
         self.graph = graph
         self.origin = origin
         self.excursion = excursion
-        self.color = color
+        self.color = color if color is not None else graph.fgcolor
         self.lastpoint = None
         self.newpoint = None
         if populate is not None and self._valid(populate):

gui/demos/epd29_async.py

@@ -1,9 +1,10 @@
-# epd29_test.py Demo program for nano_gui on an Adafruit 2.9" flexible ePaper screen
+# epd29_async.py Demo program for nano_gui on an Adafruit 2.9" flexible ePaper screen
 
 # Released under the MIT License (MIT). See LICENSE.
 # Copyright (c) 2020 Peter Hinch
 
 # color_setup must set landcsape True, asyn True and must not set demo_mode
+from cmath import exp, pi
 import uasyncio as asyncio
 from color_setup import ssd
 # On a monochrome display Writer is more efficient than CWriter.
@@ -11,11 +12,13 @@ from gui.core.writer import Writer
 from gui.core.nanogui import refresh
 from gui.widgets.meter import Meter
 from gui.widgets.label import Label
+from gui.widgets.dial import Dial, Pointer
 
 # Fonts
 import gui.fonts.arial10 as arial10
 import gui.fonts.font6 as small
 
+ssd._asyn = True  # HACK to make it config agnostic
 # Some ports don't support uos.urandom.
 # See https://github.com/peterhinch/micropython-samples/tree/master/random
 def xorshift64star(modulo, seed = 0xf9ac6ba4):
@@ -28,21 +31,20 @@ def xorshift64star(modulo, seed = 0xf9ac6ba4):
         return (x * 0x2545F4914F6CDD1D) % modulo
     return func
 
-async def fields(evt):
+async def compass(evt):  # TODO why does this not get drawn on 1st pass?
-    wri = Writer(ssd, small, verbose=False)
+    wri = Writer(ssd, arial10, verbose=False)
     wri.set_clip(False, False, False)
-    textfield = Label(wri, 0, 2, wri.stringlen('longer'))
+    v1 = 0 + 0.9j
-    numfield = Label(wri, 25, 2, wri.stringlen('99.990'), bdcolor=None)
+    v2 = exp(0 - (pi / 6) * 1j)
-    countfield = Label(wri, 0, 60, wri.stringlen('1'))
+    dial = Dial(wri, 5, 5, height = 75, ticks = 12, bdcolor=None,
-    n = 1
+            label='Direction', style = Dial.COMPASS)
-    random = xorshift64star(65535)
+    ptr = Pointer(dial)
     while True:
-        for s in ('short', 'longer', '1', ''):
+        ptr.value(v1)
-            textfield.value(s)
+        v1 *= v2
-            numfield.value('{:5.2f}'.format(random() /1000))
+#        await asyncio.sleep_ms(100)
-            countfield.value('{:1d}'.format(n))
+        await evt.wait()
-            n += 1
+
-            await evt.wait()
 
 async def multi_fields(evt):
     wri = Writer(ssd, small, verbose=False)
@@ -68,15 +70,16 @@ async def multi_fields(evt):
 
 async def meter(evt):
     wri = Writer(ssd, arial10, verbose=False)
+    wri.set_clip(False, False, False)
     row = 10
-    col = 150
+    col = 170
     args = {'height' : 80,
             'width' : 15,
             'divisions' : 4,
             'style' : Meter.BAR}
     m0 = Meter(wri, row, col, legends=('0.0', '0.5', '1.0'), **args)
-    m1 = Meter(wri, row, col + 50, legends=('-1', '0', '+1'), **args)
+    m1 = Meter(wri, row, col + 40, legends=('-1', '0', '+1'), **args)
-    m2 = Meter(wri, row, col + 100, legends=('-1', '0', '+1'), **args)
+    m2 = Meter(wri, row, col + 80, legends=('-1', '0', '+1'), **args)
     random = xorshift64star(2**24 - 1)
     while True:
         steps = 10
@@ -93,7 +96,7 @@ async def main():
     evt = asyncio.Event()
     asyncio.create_task(meter(evt))
     asyncio.create_task(multi_fields(evt))
-    asyncio.create_task(fields(evt))
+    asyncio.create_task(compass(evt))
     while True:
         # Normal procedure before refresh, but 10s sleep should mean it always returns immediately
         await ssd.wait()
@@ -103,7 +106,7 @@ async def main():
         # framebuffer in background
         evt.set()
         evt.clear()
-        await asyncio.sleep(20)  # Allow for slow refresh
+        await asyncio.sleep(10)  # Allow for slow refresh
         
         
 tstr = '''Test of asynchronous code updating the EPD. This should

gui/demos/epd29_sync.py

@@ -0,0 +1,79 @@
+# epd29_sync.py Demo of synchronous code on 2.9" EPD display
+
+# Released under the MIT License (MIT). See LICENSE.
+# Copyright (c) 2020 Peter Hinch
+
+# color_setup must set landcsape True, asyn False and must not set demo_mode
+
+from math import pi, sin
+from color_setup import ssd
+from gui.core.writer import Writer
+from gui.core.nanogui import refresh
+from gui.core.fplot import CartesianGraph, Curve
+from gui.widgets.meter import Meter
+from gui.widgets.label import Label
+from gui.widgets.dial import Dial, Pointer
+
+# Fonts
+import gui.fonts.arial10 as arial10
+import gui.fonts.freesans20 as large
+
+wri = Writer(ssd, arial10, verbose=False)
+wri.set_clip(False, False, False)
+
+wri_large = Writer(ssd, large, verbose=False)
+wri_large.set_clip(False, False, False)
+
+# 296*128
+def graph():
+    row, col, ht, wd = 5, 140, 75, 150
+    def populate():
+        x = -0.998
+        while x < 1.01:
+            z = 6 * pi * x
+            y = sin(z) / z
+            yield x, y
+            x += 0.05
+
+    g = CartesianGraph(wri, row, col, height = ht, width = wd, bdcolor=False)
+    curve2 = Curve(g, None, populate())
+    Label(wri, row + ht + 5, col - 10, '-2.0  t: secs')
+    Label(wri, row + ht + 5, col - 8 + int(wd//2), '0.0')
+    Label(wri, row + ht + 5, col - 10 + wd, '2.0')
+
+def compass():
+    dial = Dial(wri, 5, 5, height = 75, ticks = 12, bdcolor=None,
+            label='Direction', style = Dial.COMPASS)
+    ptr = Pointer(dial)
+    ptr.value(1 + 1j)
+
+def meter():
+    m = Meter(wri, 5, 100, height = 75, divisions = 4,
+             label='Peak', style=Meter.BAR, legends=('0', '50', '100'))
+    m.value(0.72)
+
+def labels():
+    row = 100
+    col = 0
+    Label(wri_large, row, col, 'Seismograph')
+    col = 140
+    Label(wri, row, col + 0, 'Event time')
+    Label(wri, row, col + 60, '01:35', bdcolor=None)
+    Label(wri, row, col + 95, 'UTC')
+    row = 115
+    Label(wri, row, col + 0, 'Event date')
+    Label(wri, row, col + 60, '6th Jan 2021', bdcolor=None)
+    
+def main():
+    refresh(ssd, True)
+    graph()
+    compass()
+    meter()
+    labels()
+    ssd.wait_until_ready()
+    refresh(ssd)
+    print('Waiting for display update')
+    ssd.wait_until_ready()
+
+main()
+