Update setup_examples/ili9486_pico.py.

setup_examples/ili9486_pico.py

@@ -1,23 +1,53 @@
 # ili9486_pico.py Customise for your hardware config
 
 # Released under the MIT License (MIT). See LICENSE.
+# Copyright (c) 2023 Peter Hinch
 
-# ILI9486 on Pi Pico
-# See DRIVERS.md for wiring details.
+# As written, supports:
+# ili9486 320x480 displays on Pi Pico with ILI9486 or HX8357D controller.
+# Edit the driver import statement for other displays.
+# Large frame buffer requires GUI to be frozen as bytecode.
+
+# Tested displays:
+# https://www.adafruit.com/product/2050
+# https://www.waveshare.com/product/3.5inch-rpi-lcd-a.htm
+
+# Demo of initialisation procedure designed to minimise risk of memory fail
+# when instantiating the frame buffer. The aim is to do this as early as
+# possible before importing other modules.
+
+# WIRING
+# Pico      Display
+# GPIO Pin
+# 3v3  36   Vin
+# IO6   9   CLK  Hardware SPI0
+# IO7  10   DATA (AKA SI MOSI)
+# IO8  11   DC
+# IO9  12   Rst
+# Gnd  13   Gnd
+# IO10 14   CS
+
+# Pushbuttons are wired between the pin and Gnd
+# Pico pin  Meaning
+# 16        Operate current control
+# 17        Decrease value of current control
+# 18        Select previous control
+# 19        Select next control
+# 20        Increase value of current control
 
 from machine import Pin, SPI, freq
 import gc
 
 from drivers.ili94xx.ili9486 import ILI9486 as SSD
 freq(250_000_000)  # RP2 overclock
-
+# Create and export an SSD instance
 pdc = Pin(8, Pin.OUT, value=0)  # Arbitrary pins
 prst = Pin(9, Pin.OUT, value=1)
 pcs = Pin(10, Pin.OUT, value=1)
 spi = SPI(0, sck=Pin(6), mosi=Pin(7), miso=Pin(4), baudrate=30_000_000)
 gc.collect()  # Precaution before instantiating framebuf
 ssd = SSD(spi, pcs, pdc, prst)
-gc.collect()
+
 from gui.core.ugui import Display
 # Create and export a Display instance
 # Define control buttons
@@ -26,4 +56,4 @@ sel = Pin(16, Pin.IN, Pin.PULL_UP)  # Operate current control
 prev = Pin(18, Pin.IN, Pin.PULL_UP)  # Move to previous control
 increase = Pin(20, Pin.IN, Pin.PULL_UP)  # Increase control's value
 decrease = Pin(17, Pin.IN, Pin.PULL_UP)  # Decrease control's value
-display = Display(ssd, nxt, sel, prev, increase, decrease)  # Pushbutton control
+display = Display(ssd, nxt, sel, prev, increase, decrease)