add sample code for using a waveshare 1.54in WBR epaper display

main.py

@@ -1,20 +1,75 @@
 import uPyConfig
 
-hw = uPyConfig.esp32(variant='wemos-lolin32')
-#print family, variant and IP address (using oled, if available on-board)
+hw = uPyConfig.esp32()
 import webrepl
 webrepl.start()
+#print family, variant and IP address (using oled, if available on-board)
 import init_sample
 init_sample.PrintHWInfo(hw)
 
 # Main app
-import uJIRA
-from machine import Pin, TouchPad
-jcloud = uJIRA.client('tradeprint.atlassian.net')
-auth = {
-    'method': 'basic-auth', #Only basic-auth is supported for now, oauth is a headache
-    'username': '',
-    'password': '',
-}
+from machine import Pin, TouchPad, SPI
+import framebuf
+from epaper1in54b import EPD
 
-jcloud.login(auth)
+#confusingly, a 1 (interpreted in the display as 0xff) is the "off" state for the pixel
+#whereas a 0 is the "on" state
+c_blank=1
+c_filled=0
+#our display is a 200x200 display
+d_w=200
+d_h=200
+
+#set up framebuffers and backing buffers
+#because we have a display with three colours (red, white, black), this is presented logically
+#as two separate monochrome "frames" of equal size
+#so when rendering, the display_frame function will take as many frames as there are non-white colours
+#this could be used for easy inversion by just swapping the order of arguments to display_frame(buf,buf)
+#some documentation suggests that framebuffer should be initialised directly
+#using FrameBuffer(bytearray(size..))
+#however this causes problems when trying to use the fb as a buffer
+#because it is not "subscriptable"
+#thus the underlying buffer MUST be separated, as it cannot be directly read from inside the fb
+fb_buffer_black=bytearray(d_w*d_h//8)
+fb_buffer_red=bytearray(d_w*d_h//8)
+fb_black=framebuf.FrameBuffer(fb_buffer_black,d_w,d_h,framebuf.MONO_HLSB)
+fb_red=framebuf.FrameBuffer(fb_buffer_red,d_w,d_h,framebuf.MONO_HLSB)
+fb_black.fill(c_blank)
+fb_red.fill(c_blank)
+
+#SPI is one of the more poorly documented parts of the micropython esp32 port
+#i wish i could make this prettier
+spi_mosi=Pin(23)
+spi_miso=Pin(19)
+spi_sck=Pin(18)
+spi_cs=Pin(2)
+spi_dc=Pin(4)
+spi_rst=Pin(0)
+spi_busy=Pin(15)
+
+#set up SPI, then set up the ePaper display
+#i'm using a WaveShare ePaper SPI 1.54in. display model (B) with a third colour (red)
+#this example code will work identically for the model (C) with yellow as its third colour
+#but is easily adaptable for other waveshare displays
+spi=SPI(2,baudrate=200000,polarity=0,phase=0,mosi=spi_mosi,miso=spi_miso,sck=spi_sck)
+epd=EPD(spi,cs=spi_cs,dc=spi_dc,rst=spi_rst,busy=spi_busy)
+
+#only needs to be run once upon startup, unless the display is placed into low-power mode
+#using epd.sleep(), then you need to run either epd.init() or epd.reset()
+epd.init()
+
+#helper function
+def updatedisplay():
+	epd.display_frame(fb_buffer_black,fb_buffer_red)
+
+updatedisplay()
+from time import sleep_ms
+sleep_ms(1000)
+ln=0
+while ln<200:
+	fb_black.text("what's up i'm sleepy",5,ln,c_filled)
+	ln+=10
+	fb_red.text("what's up i'm sleepy",5,ln,c_filled)
+	ln+=10
+
+updatedisplay()