pico_epaper_42_v2.py: Change default pin to match hardware.

drivers/epaper/pico_epaper_42_v2.py

@@ -34,6 +34,7 @@
 # Waveshare URLs
 # Main page: https://www.waveshare.com/pico-epaper-4.2.htm
 # Wiki: https://www.waveshare.com/wiki/Pico-ePaper-4.2
+# Another wiki: https://www.waveshare.com/wiki/4.2inch_e-Paper_Module_Manual#Introduction
 # Code: https://github.com/waveshareteam/Pico_ePaper_Code/blob/main/python/Pico-ePaper-4.2_V2.py
 
 from machine import Pin, SPI
@@ -56,9 +57,8 @@ _EPD_WIDTH = const(400)
 _BWIDTH = _EPD_WIDTH // 8
 _EPD_HEIGHT = const(300)
 
-_RST_PIN = 12
-# changed default to 7, as this can be confusing on pico -- pin 8 for SPI1 is the Rx, which overrides DC pin if miso is set to none
-_DC_PIN = 7
+_RST_PIN = 12  # Pin defaults match wiring of Pico socket
+_DC_PIN = 8
 _CS_PIN = 9
 _BUSY_PIN = 13
 

setup_examples/pico_epaper_42_pico.py

@@ -29,14 +29,16 @@
 
 from machine import Pin, SPI, freq
 import gc
-from drivers.epaper.pico_epaper_42 import EPD as SSD
+from drivers.epaper.pico_epaper_42 import EPD as SSD  # V1
+
+# from drivers.epaper.pico_epaper_42_V2 import EPD as SSD  # V2
 freq(250_000_000)  # RP2 overclock
 # Create and export an SSD instance
 prst = Pin(9, Pin.OUT, value=1)
 pcs = Pin(10, Pin.OUT, value=1)
 pdc = Pin(8, Pin.OUT, value=0)  # Arbitrary pins
 busy = Pin(15, Pin.IN)
-# Datasheet allows 10MHz
+# V1 UC8176 datasheet allows 10MHz. V2: Waveshare code uses 4MHz
 spi = SPI(0, sck=Pin(6), mosi=Pin(7), miso=Pin(4), baudrate=10_000_000)
 gc.collect()  # Precaution before instantiating framebuf
 
@@ -45,6 +47,7 @@ gc.collect()  # Precaution before instantiating framebuf
 ssd = SSD(spi, pcs, pdc, prst, busy)
 gc.collect()
 from gui.core.ugui import Display, quiet
+
 # quiet()
 # Create and export a Display instance
 # Define control buttons