From ff208d767741104f7d2644a58269d7064d4c1b6a Mon Sep 17 00:00:00 2001 From: Scott Shawcroft Date: Sat, 25 Mar 2017 12:04:49 +0000 Subject: Add low-level OneWire support class. This class focuses on the timing sensitive parts of the protocol. Everything else will be done by Python code. This also establishes that its OK to back a nativeio class with a bitbang implementation when no hardware acceleration exists. When it does, then bitbangio should be used to explicitly bitbang a protocol. --- shared-module/bitbangio/OneWire.c | 80 +++++++++++++++++++++++++++++++++++++++ shared-module/bitbangio/types.h | 7 +++- shared-module/nativeio/OneWire.c | 52 +++++++++++++++++++++++++ shared-module/nativeio/OneWire.h | 42 ++++++++++++++++++++ 4 files changed, 180 insertions(+), 1 deletion(-) create mode 100644 shared-module/bitbangio/OneWire.c create mode 100644 shared-module/nativeio/OneWire.c create mode 100644 shared-module/nativeio/OneWire.h (limited to 'shared-module') diff --git a/shared-module/bitbangio/OneWire.c b/shared-module/bitbangio/OneWire.c new file mode 100644 index 000000000..5f45b3baf --- /dev/null +++ b/shared-module/bitbangio/OneWire.c @@ -0,0 +1,80 @@ +/* + * This file is part of the Micro Python project, http://micropython.org/ + * + * The MIT License (MIT) + * + * Copyright (c) 2017 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 "common-hal/microcontroller/types.h" +#include "shared-bindings/bitbangio/OneWire.h" +#include "shared-bindings/microcontroller/__init__.h" +#include "shared-bindings/nativeio/DigitalInOut.h" +#include "shared-module/bitbangio/types.h" + +// Durations are taken from here: https://www.maximintegrated.com/en/app-notes/index.mvp/id/126 + +void shared_module_bitbangio_onewire_construct(bitbangio_onewire_obj_t* self, + const mcu_pin_obj_t* pin) { + self->pin.base.type = &nativeio_digitalinout_type; + common_hal_nativeio_digitalinout_construct(&self->pin, pin); +} + +void shared_module_bitbangio_onewire_deinit(bitbangio_onewire_obj_t* self) { + common_hal_nativeio_digitalinout_deinit(&self->pin); +} + +bool shared_module_bitbangio_onewire_reset(bitbangio_onewire_obj_t* self) { + common_hal_mcu_disable_interrupts(); + common_hal_nativeio_digitalinout_switch_to_output(&self->pin, false, DRIVE_MODE_OPEN_DRAIN); + common_hal_mcu_delay_us(480); + common_hal_nativeio_digitalinout_switch_to_input(&self->pin, PULL_NONE); + common_hal_mcu_delay_us(70); + bool value = common_hal_nativeio_digitalinout_get_value(&self->pin); + common_hal_mcu_delay_us(410); + common_hal_mcu_enable_interrupts(); + return value; +} + +bool shared_module_bitbangio_onewire_read_bit(bitbangio_onewire_obj_t* self) { + common_hal_mcu_disable_interrupts(); + common_hal_nativeio_digitalinout_switch_to_output(&self->pin, false, DRIVE_MODE_OPEN_DRAIN); + common_hal_mcu_delay_us(6); + common_hal_nativeio_digitalinout_switch_to_input(&self->pin, PULL_NONE); + // TODO(tannewt): Test with more devices and maybe make the delays + // configurable. This should be 9 by the datasheet but all bits read as 1 + // then. + common_hal_mcu_delay_us(6); + bool value = common_hal_nativeio_digitalinout_get_value(&self->pin); + common_hal_mcu_delay_us(55); + common_hal_mcu_enable_interrupts(); + return value; +} + +void shared_module_bitbangio_onewire_write_bit(bitbangio_onewire_obj_t* self, + bool bit) { + common_hal_mcu_disable_interrupts(); + common_hal_nativeio_digitalinout_switch_to_output(&self->pin, false, DRIVE_MODE_OPEN_DRAIN); + common_hal_mcu_delay_us(bit? 6 : 60); + common_hal_nativeio_digitalinout_switch_to_input(&self->pin, PULL_NONE); + common_hal_mcu_delay_us(bit? 64 : 10); + common_hal_mcu_enable_interrupts(); +} diff --git a/shared-module/bitbangio/types.h b/shared-module/bitbangio/types.h index 719f36a93..8fd4a48c4 100644 --- a/shared-module/bitbangio/types.h +++ b/shared-module/bitbangio/types.h @@ -27,7 +27,7 @@ #ifndef __MICROPY_INCLUDED_SHARED_MODULE_BITBANGIO_TYPES_H__ #define __MICROPY_INCLUDED_SHARED_MODULE_BITBANGIO_TYPES_H__ -#include "common-hal/nativeio/types.h" +#include "common-hal/nativeio/DigitalInOut.h" #include "py/obj.h" @@ -39,6 +39,11 @@ typedef struct { volatile bool locked; } bitbangio_i2c_obj_t; +typedef struct { + mp_obj_base_t base; + nativeio_digitalinout_obj_t pin; +} bitbangio_onewire_obj_t; + typedef struct { mp_obj_base_t base; nativeio_digitalinout_obj_t clock; diff --git a/shared-module/nativeio/OneWire.c b/shared-module/nativeio/OneWire.c new file mode 100644 index 000000000..490f9b109 --- /dev/null +++ b/shared-module/nativeio/OneWire.c @@ -0,0 +1,52 @@ +/* + * This file is part of the Micro Python project, http://micropython.org/ + * + * The MIT License (MIT) + * + * Copyright (c) 2017 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. + */ + +// Wraps the bitbangio implementation of OneWire for use in nativeio. +#include "common-hal/microcontroller/types.h" +#include "shared-bindings/bitbangio/OneWire.h" +#include "common-hal/nativeio/types.h" + +void common_hal_nativeio_onewire_construct(nativeio_onewire_obj_t* self, + const mcu_pin_obj_t* pin) { + shared_module_bitbangio_onewire_construct(&self->bitbang, pin); +} + +void common_hal_nativeio_onewire_deinit(nativeio_onewire_obj_t* self) { + shared_module_bitbangio_onewire_deinit(&self->bitbang); +} + +bool common_hal_nativeio_onewire_reset(nativeio_onewire_obj_t* self) { + return shared_module_bitbangio_onewire_reset(&self->bitbang); +} + +bool common_hal_nativeio_onewire_read_bit(nativeio_onewire_obj_t* self) { + return shared_module_bitbangio_onewire_read_bit(&self->bitbang); +} + +void common_hal_nativeio_onewire_write_bit(nativeio_onewire_obj_t* self, + bool bit) { + shared_module_bitbangio_onewire_write_bit(&self->bitbang, bit); +} diff --git a/shared-module/nativeio/OneWire.h b/shared-module/nativeio/OneWire.h new file mode 100644 index 000000000..3704c55a3 --- /dev/null +++ b/shared-module/nativeio/OneWire.h @@ -0,0 +1,42 @@ +/* + * This file is part of the MicroPython project, http://micropython.org/ + * + * The MIT License (MIT) + * + * Copyright (c) 2017 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. + */ + +// This defines the types used to underly the standard nativeio Python objects. +// The shared API is defined in terms of these types. + +#ifndef __MICROPY_INCLUDED_ATMEL_SAMD_SHARED_MODULE_NATIVEIO_ONEWIRE_H__ +#define __MICROPY_INCLUDED_ATMEL_SAMD_SHARED_MODULE_NATIVEIO_ONEWIRE_H__ + +#include "shared-module/bitbangio/types.h" + +#include "py/obj.h" + +typedef struct { + mp_obj_base_t base; + bitbangio_onewire_obj_t bitbang; +} nativeio_onewire_obj_t; + +#endif // __MICROPY_INCLUDED_ATMEL_SAMD_SHARED_MODULE_NATIVEIO_ONEWIRE_H__ -- cgit v1.2.3