with the i2c bus operating at 400kHz this achieves a 4.8kHz SPI clock
rate which could be worse.
It accepts the same style of init sequence as displayio.
tested by scoping the pins on the espressif lcd dev kit with a dummy init sequence:
```python
dotclockframebuffer.ioexpander_send_init_sequence(
bus=bus,
i2c_address=expander_addr,
gpio_address=1,
gpio_data_len=1,
gpio_data=0xff,
cs_bit=1,
mosi_bit=3,
clk_bit=2,
init_sequence=init_sequence)
```
On my i5-1235U laptop this speeds LTO "partition=balanced" builds
substantially, because each "partition" can be run on a separate
CPU thread. I used "pygamer" as my test build with a parallelism of
`-j4`, and took the best elapsed time reported over 4 builds.
The improvement was from 34.6s to 24.0s (-30%).
A link-only build (rm build-pygamer/firmware.elf; make -j...) improved
from1 17.4s to 5.1s (-70%)
The size of the resulting firmware is unchanged.
Boards that are nearly full use "-flto-partition=one" to improve code
size optimization. When LTO partition is "one", this feature doesn't help
but it doesn't seem to negatively affect anything either (tested
building trinket_m0)
This class allows much more expressive sound synthesis:
* tremolo & vibrato
* arbitrary frequency
* different evelope & waveform per note
* all properties dynamically settable from Python code
PicoDVI in CP support 640x480 and 800x480 on Feather DVI, Pico and
Pico W. 1 and 2 bit grayscale are full resolution. 8 and 16 bit
color are half resolution.
Memory layout is modified to give the top most 4k of ram to the
second core. Its MPU is used to prevent flash access after startup.
The port saved word is moved to a watchdog scratch register so that
it doesn't get overwritten by other things in RAM.
Right align status bar and scroll area. This normally gives a few
pixels of padding on the left hand side and improves the odds it is
readable in a case. Fixes#7562
Fixes c stack checking. The length was correct but the top was being
set to the current stack pointer instead of the correct top.
Fixes#7643
This makes Bitmap subscr raise IndexError instead of ValueError
when the index arguments are wrong.
In contrast to MidiTrack, this can be controlled from Python code,
turning notes on/off as desired.
Not tested on real HW yet, just the acceptance test based on checking
which notes it thinks are held internally.
.. a fast helper for animations. It is similar to and inspired by the
PixelMap helper in Adafruit LED Animation library, but with an extremely
fast 'paste' method for setting a series of pixels. This is a common
operation for many animations, and can give a substantial speed improvement.
It's named `adafruit_pixelmap` so that we can package a compatible version
in pure Python for systems that can't fit it in C in flash, or for
Blinka.
This is a proof of concept and can make a very fast comet animation:
```python
import time
import adafruit_pixelbuf
import adafruti_pixelmap
import board
import neopixel
from supervisor import ticks_ms
from adafruit_led_animation.animation.solid import Solid
from adafruit_led_animation import color
pixel_pin = board.GP0
pixel_num = 96
pixels = neopixel.NeoPixel(pixel_pin, pixel_num, brightness=1, auto_write=False, pixel_order="RGB")
evens = adafruit_pixelmap.PixelMap(pixels, tuple(range(0, pixel_num, 2)))
odd_indices = tuple((i, i+2) for i in range(1, pixel_num, 4))
print(odd_indices)
odds = adafruit_pixelbuf.PixelMap(pixels, odd_indices)
assert len(odds) == len(odd_indices)
comet_length = 16
comet1 = [color.calculate_intensity(color.GREEN, ((1+i) / comet_length) ** 2.4)
for i in range(comet_length)]
comet2 = [color.calculate_intensity(color.PURPLE, ((1+i) / comet_length) ** 2.4)
for i in range(comet_length)]
pos1 = 0
pos2 = 96//4
while True:
evens.paste(comet1, pos1, wrap=True, reverse=False, others=0)
pos1 = (pos1 + 1) % len(evens)
odds.paste(comet2, pos2, wrap=True, reverse=True, others=0)
pos2 = (pos2 - 1) % len(odds)
pixels.show()
m = ticks_ms()
if m % 2000 > 1000:
time.sleep(.02)
```
.. the default is intended to be the equivalent of the original,
implementing `DISPLAYIO && TERMINALIO`.
This is a possible alternative to #6889, if I understand the intent.
