circuitpython/shared-bindings/neopixel_write/__init__.c

143 lines
5.7 KiB
C
Raw Permalink Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 Scott Shawcroft for Adafruit Industries
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "shared-bindings/neopixel_write/__init__.h"
#include "py/obj.h"
#include "py/mphal.h"
#include "py/runtime.h"
#include "shared-bindings/digitalio/DigitalInOut.h"
#include "shared-bindings/util.h"
// RGB LED timing information:
// From the WS2811 datasheet: high speed mode
// - T0H 0 code,high voltage time 0.25 us +-150ns
// - T1H 1 code,high voltage time 0.6 us +-150ns
// - T0L 0 code,low voltage time 1.0 us +-150ns
// - T1L 1 code,low voltage time 0.65 us +-150ns
// - RES low voltage time Above 50us
// From the SK6812 datasheet:
// - T0H 0 code, high level time 0.3us +-0.15us
// - T1H 1 code, high level time 0.6us +-0.15us
// - T0L 0 code, low level time 0.9us +-0.15us
// - T1L 1 code, low level time 0.6us +-0.15us
// - Trst Reset codelow level time 80us
// From the WS2812 datasheet:
// - T0H 0 code, high voltage time 0.35us +-150ns
// - T1H 1 code, high voltage time 0.7us +-150ns
// - T0L 0 code, low voltage time 0.8us +-150ns
// - T1L 1 code, low voltage time 0.6us +-150ns
// - RES low voltage time Above 50us
// From the WS28212B datasheet:
// - T0H 0 code, high voltage time 0.4us +-150ns
// - T1H 1 code, high voltage time 0.8us +-150ns
// - T0L 0 code, low voltage time 0.85us +-150ns
// - T1L 1 code, low voltage time 0.45us +-150ns
// - RES low voltage time Above 50us
// The timings used in various ports do not always follow the guidelines above.
// In general, a zero bit is about 300ns high, 900ns low.
// A one bit is about 700ns high, 500ns low.
// But the ports vary based on implementation considerations; the proof is in the testing.
// https://adafru.it/5225 is more sensitive to timing and should be included in testing.
STATIC void check_for_deinit(digitalio_digitalinout_obj_t *self) {
if (common_hal_digitalio_digitalinout_deinited(self)) {
raise_deinited_error();
}
}
//| """Low-level neopixel implementation
//|
//| The `neopixel_write` module contains a helper method to write out bytes in
//| the 800khz neopixel protocol.
//|
//| For example, to turn off a single neopixel (like the status pixel on Express
//| boards.)
//|
//| .. code-block:: python
//|
//| import board
//| import neopixel_write
//| import digitalio
//|
//| pin = digitalio.DigitalInOut(board.NEOPIXEL)
//| pin.direction = digitalio.Direction.OUTPUT
//| pixel_off = bytearray([0, 0, 0])
//| neopixel_write.neopixel_write(pin, pixel_off)
//|
//| .. note::
//|
//| This module is typically not used by user level code.
//|
//| For more information on actually using NeoPixels, refer to the `CircuitPython
//| Essentials Learn guide <https://learn.adafruit.com/circuitpython-essentials/circuitpython-neopixel>`_
//|
//| For a much more thorough guide about using NeoPixels, refer to the `Adafruit NeoPixel Überguide
//| <https://learn.adafruit.com/adafruit-neopixel-uberguide>`_.
//|
//| """
//|
//| def neopixel_write(digitalinout: digitalio.DigitalInOut, buf: ReadableBuffer) -> None:
//| """Write buf out on the given DigitalInOut.
//|
//| :param ~digitalio.DigitalInOut digitalinout: the DigitalInOut to output with
//| :param ~circuitpython_typing.ReadableBuffer buf: The bytes to clock out. No assumption is made about color order
//| """
//| ...
//|
STATIC mp_obj_t neopixel_write_neopixel_write_(mp_obj_t digitalinout_obj, mp_obj_t buf) {
const digitalio_digitalinout_obj_t *digitalinout =
mp_arg_validate_type(digitalinout_obj, &digitalio_digitalinout_type, MP_QSTR_digitalinout);
// Check to see if the NeoPixel has been deinited before writing to it.
check_for_deinit(digitalinout_obj);
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(buf, &bufinfo, MP_BUFFER_READ);
// Call platform's neopixel write function with provided buffer and options.
common_hal_neopixel_write(digitalinout, (uint8_t *)bufinfo.buf, bufinfo.len);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(neopixel_write_neopixel_write_obj, neopixel_write_neopixel_write_);
STATIC const mp_rom_map_elem_t neopixel_write_module_globals_table[] = {
{ MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_neopixel_write) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_neopixel_write), (mp_obj_t)&neopixel_write_neopixel_write_obj },
};
STATIC MP_DEFINE_CONST_DICT(neopixel_write_module_globals, neopixel_write_module_globals_table);
const mp_obj_module_t neopixel_write_module = {
.base = { &mp_type_module },
.globals = (mp_obj_dict_t *)&neopixel_write_module_globals,
};
MP_REGISTER_MODULE(MP_QSTR_neopixel_write, neopixel_write_module);