circuitpython/shared-bindings/neopixel_write/__init__.c

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/*
* 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"
#include "supervisor/shared/translate.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)"""
//|
//| 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) {
if (!mp_obj_is_type(digitalinout_obj, &digitalio_digitalinout_type)) {
mp_raise_TypeError_varg(translate("Expected a %q"), digitalio_digitalinout_type.name);
}
// Convert parameters into expected types.
const digitalio_digitalinout_obj_t *digitalinout = MP_OBJ_TO_PTR(digitalinout_obj);
// 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, CIRCUITPY_NEOPIXEL_WRITE);