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micropython/ports/stm32/dac.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013-2019 Damien P. George
*
* 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 <stdio.h>
#include <stdint.h>
#include <string.h>
#include "py/runtime.h"
#include "py/mphal.h"
#include "timer.h"
#include "dac.h"
#include "dma.h"
#include "pin.h"
/// \moduleref pyb
/// \class DAC - digital to analog conversion
///
/// The DAC is used to output analog values (a specific voltage) on pin X5 or pin X6.
/// The voltage will be between 0 and 3.3V.
///
/// *This module will undergo changes to the API.*
///
/// Example usage:
///
/// from pyb import DAC
///
/// dac = DAC(1) # create DAC 1 on pin X5
/// dac.write(128) # write a value to the DAC (makes X5 1.65V)
///
/// To output a continuous sine-wave:
///
/// import math
/// from pyb import DAC
///
/// # create a buffer containing a sine-wave
/// buf = bytearray(100)
/// for i in range(len(buf)):
/// buf[i] = 128 + int(127 * math.sin(2 * math.pi * i / len(buf)))
///
/// # output the sine-wave at 400Hz
/// dac = DAC(1)
/// dac.write_timed(buf, 400 * len(buf), mode=DAC.CIRCULAR)
#if defined(MICROPY_HW_ENABLE_DAC) && MICROPY_HW_ENABLE_DAC
#if defined(STM32H5) || defined(STM32H7)
#define DAC DAC1
#endif
#if defined(TIM6)
STATIC void TIM6_Config(uint freq) {
// Init TIM6 at the required frequency (in Hz)
TIM_HandleTypeDef *tim = timer_tim6_init(freq);
// TIM6 TRGO selection
TIM_MasterConfigTypeDef config;
config.MasterOutputTrigger = TIM_TRGO_UPDATE;
config.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
HAL_TIMEx_MasterConfigSynchronization(tim, &config);
// TIM6 start counter
HAL_TIM_Base_Start(tim);
}
#endif
STATIC uint32_t TIMx_Config(mp_obj_t timer) {
// TRGO selection to trigger DAC
TIM_HandleTypeDef *tim = pyb_timer_get_handle(timer);
TIM_MasterConfigTypeDef config;
config.MasterOutputTrigger = TIM_TRGO_UPDATE;
config.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
HAL_TIMEx_MasterConfigSynchronization(tim, &config);
// work out the trigger channel (only certain ones are supported)
if (tim->Instance == TIM2) {
return DAC_TRIGGER_T2_TRGO;
#if defined(TIM4)
} else if (tim->Instance == TIM4) {
return DAC_TRIGGER_T4_TRGO;
#endif
#if defined(TIM5) && defined(DAC_TRIGGER_T5_TRGO) // G474 doesn't have this
} else if (tim->Instance == TIM5) {
return DAC_TRIGGER_T5_TRGO;
#endif
#if defined(TIM6)
} else if (tim->Instance == TIM6) {
return DAC_TRIGGER_T6_TRGO;
#endif
#if defined(TIM7)
} else if (tim->Instance == TIM7) {
return DAC_TRIGGER_T7_TRGO;
#endif
#if defined(TIM8)
} else if (tim->Instance == TIM8) {
return DAC_TRIGGER_T8_TRGO;
#endif
} else {
mp_raise_ValueError(MP_ERROR_TEXT("Timer does not support DAC triggering"));
}
}
STATIC void dac_deinit(uint32_t dac_channel) {
DAC->CR &= ~(DAC_CR_EN1 << dac_channel);
#if defined(STM32G0) || defined(STM32G4) || defined(STM32H5) || defined(STM32H7) || defined(STM32L4)
DAC->MCR = (DAC->MCR & ~(DAC_MCR_MODE1_Msk << dac_channel)) | (DAC_OUTPUTBUFFER_DISABLE << dac_channel);
#else
DAC->CR |= DAC_CR_BOFF1 << dac_channel;
#endif
}
void dac_deinit_all(void) {
dac_deinit(DAC_CHANNEL_1);
#if !defined(STM32L452xx)
dac_deinit(DAC_CHANNEL_2);
#endif
}
STATIC void dac_config_channel(uint32_t dac_channel, uint32_t trig, uint32_t outbuf) {
DAC->CR &= ~(DAC_CR_EN1 << dac_channel);
uint32_t cr_off = DAC_CR_DMAEN1 | DAC_CR_MAMP1 | DAC_CR_WAVE1 | DAC_CR_TSEL1 | DAC_CR_TEN1;
uint32_t cr_on = trig;
#if defined(STM32G0) || defined(STM32G4) || defined(STM32H5) || defined(STM32H7) || defined(STM32L4)
DAC->MCR = (DAC->MCR & ~(DAC_MCR_MODE1_Msk << dac_channel)) | (outbuf << dac_channel);
#else
cr_off |= DAC_CR_BOFF1;
cr_on |= outbuf;
#endif
DAC->CR = (DAC->CR & ~(cr_off << dac_channel)) | (cr_on << dac_channel);
}
STATIC void dac_set_value(uint32_t dac_channel, uint32_t align, uint32_t value) {
uint32_t base;
if (dac_channel == DAC_CHANNEL_1) {
base = (uint32_t)&DAC->DHR12R1;
#if !defined(STM32L452xx)
} else {
base = (uint32_t)&DAC->DHR12R2;
#endif
}
*(volatile uint32_t *)(base + align) = value;
}
STATIC void dac_start(uint32_t dac_channel) {
DAC->CR |= DAC_CR_EN1 << dac_channel;
}
STATIC void dac_start_dma(uint32_t dac_channel, const dma_descr_t *dma_descr, uint32_t dma_mode, uint32_t bit_size, uint32_t dac_align, size_t len, void *buf) {
uint32_t dma_align;
if (bit_size == 8) {
#if defined(STM32G4)
// For STM32G4, DAC registers have to be accessed by words (32-bit).
dma_align = DMA_MDATAALIGN_BYTE | DMA_PDATAALIGN_WORD;
#elif defined(STM32H5)
dma_align = 0;
#else
dma_align = DMA_MDATAALIGN_BYTE | DMA_PDATAALIGN_BYTE;
#endif
} else {
#if defined(STM32G4)
// For STM32G4, DAC registers have to be accessed by words (32-bit).
dma_align = DMA_MDATAALIGN_HALFWORD | DMA_PDATAALIGN_WORD;
#elif defined(STM32H5)
dma_align = 0;
#else
dma_align = DMA_MDATAALIGN_HALFWORD | DMA_PDATAALIGN_HALFWORD;
#endif
}
uint32_t base;
if (dac_channel == DAC_CHANNEL_1) {
base = (uint32_t)&DAC->DHR12R1;
#if !defined(STM32L452xx)
} else {
base = (uint32_t)&DAC->DHR12R2;
#endif
}
dma_nohal_deinit(dma_descr);
dma_nohal_init(dma_descr, DMA_MEMORY_TO_PERIPH | dma_mode | dma_align);
dma_nohal_start(dma_descr, (uint32_t)buf, base + dac_align, len);
DAC->CR |= DAC_CR_EN1 << dac_channel;
}
/******************************************************************************/
// MicroPython bindings
typedef struct _pyb_dac_obj_t {
mp_obj_base_t base;
uint8_t dac_channel; // DAC_CHANNEL_1 or DAC_CHANNEL_2. STM32L452 only has CHANNEL_1.
uint8_t bits; // 8 or 12
uint8_t outbuf_single;
uint8_t outbuf_waveform;
} pyb_dac_obj_t;
STATIC pyb_dac_obj_t pyb_dac_obj[2];
STATIC void pyb_dac_reconfigure(pyb_dac_obj_t *self, uint32_t cr, uint32_t outbuf, uint32_t value) {
bool restart = false;
const uint32_t cr_mask = DAC_CR_DMAEN1 | DAC_CR_MAMP1 | DAC_CR_WAVE1 | DAC_CR_TSEL1 | DAC_CR_TEN1 | DAC_CR_EN1;
if (((DAC->CR >> self->dac_channel) & cr_mask) != (cr | DAC_CR_EN1)) {
const dma_descr_t *tx_dma_descr;
if (self->dac_channel == DAC_CHANNEL_1) {
tx_dma_descr = &dma_DAC_1_TX;
#if !defined(STM32L452xx)
} else {
tx_dma_descr = &dma_DAC_2_TX;
#endif
}
dma_nohal_deinit(tx_dma_descr);
dac_config_channel(self->dac_channel, cr, outbuf);
restart = true;
}
dac_set_value(self->dac_channel, DAC_ALIGN_12B_R, value);
if (restart) {
dac_start(self->dac_channel);
}
}
STATIC void pyb_dac_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
pyb_dac_obj_t *self = MP_OBJ_TO_PTR(self_in);
mp_printf(print, "DAC(%u, bits=%u)",
self->dac_channel == DAC_CHANNEL_1 ? 1 : 2,
self->bits);
}
STATIC mp_obj_t pyb_dac_init_helper(pyb_dac_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_bits, MP_ARG_INT, {.u_int = 8} },
{ MP_QSTR_buffering, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
};
// parse args
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
// GPIO configuration
mp_hal_pin_obj_t pin;
if (self->dac_channel == DAC_CHANNEL_1) {
pin = pin_A4;
#if !defined(STM32L452xx)
} else {
pin = pin_A5;
#endif
}
mp_hal_pin_config(pin, MP_HAL_PIN_MODE_ANALOG, MP_HAL_PIN_PULL_NONE, 0);
// DAC peripheral clock
#if defined(STM32F4) || defined(STM32F7)
__DAC_CLK_ENABLE();
#elif defined(STM32H7)
__HAL_RCC_DAC12_CLK_ENABLE();
#elif defined(STM32F0) || defined(STM32G0) || defined(STM32G4) || defined(STM32H5) || defined(STM32L4)
__HAL_RCC_DAC1_CLK_ENABLE();
#elif defined(STM32L1)
__HAL_RCC_DAC_CLK_ENABLE();
#else
#error Unsupported Processor
#endif
// Stop the DAC in case it was already running
DAC->CR &= ~(DAC_CR_EN1 << self->dac_channel);
// set bit resolution
if (args[0].u_int == 8 || args[0].u_int == 12) {
self->bits = args[0].u_int;
} else {
mp_raise_ValueError(MP_ERROR_TEXT("unsupported bits"));
}
// set output buffer config
if (args[1].u_obj == mp_const_none) {
// due to legacy, default values differ for single and waveform outputs
self->outbuf_single = DAC_OUTPUTBUFFER_DISABLE;
self->outbuf_waveform = DAC_OUTPUTBUFFER_ENABLE;
} else if (mp_obj_is_true(args[1].u_obj)) {
self->outbuf_single = DAC_OUTPUTBUFFER_ENABLE;
self->outbuf_waveform = DAC_OUTPUTBUFFER_ENABLE;
} else {
self->outbuf_single = DAC_OUTPUTBUFFER_DISABLE;
self->outbuf_waveform = DAC_OUTPUTBUFFER_DISABLE;
}
return mp_const_none;
}
// create the dac object
// currently support either DAC1 on X5 (id = 1) or DAC2 on X6 (id = 2)
/// \classmethod \constructor(port)
/// Construct a new DAC object.
///
/// `port` can be a pin object, or an integer (1 or 2).
/// DAC(1) is on pin X5 and DAC(2) is on pin X6.
STATIC mp_obj_t pyb_dac_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
// check arguments
mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);
// get pin/channel to output on
mp_int_t dac_id;
if (mp_obj_is_int(args[0])) {
dac_id = mp_obj_get_int(args[0]);
} else {
const machine_pin_obj_t *pin = pin_find(args[0]);
if (pin == pin_A4) {
dac_id = 1;
} else if (pin == pin_A5) {
dac_id = 2;
} else {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("Pin(%q) doesn't have DAC capabilities"), pin->name);
}
}
uint32_t dac_channel;
if (dac_id == 1) {
dac_channel = DAC_CHANNEL_1;
#if !defined(STM32L452xx)
} else if (dac_id == 2) {
dac_channel = DAC_CHANNEL_2;
#endif
} else {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("DAC(%d) doesn't exist"), dac_id);
}
pyb_dac_obj_t *dac = &pyb_dac_obj[dac_id - 1];
dac->base.type = &pyb_dac_type;
dac->dac_channel = dac_channel;
if (dac->bits == 0 || n_args > 1 || n_kw > 0) {
// configure the peripheral
mp_map_t kw_args;
mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
pyb_dac_init_helper(dac, n_args - 1, args + 1, &kw_args);
}
// return object
return MP_OBJ_FROM_PTR(dac);
}
STATIC mp_obj_t pyb_dac_init(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
return pyb_dac_init_helper(MP_OBJ_TO_PTR(args[0]), n_args - 1, args + 1, kw_args);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_dac_init_obj, 1, pyb_dac_init);
/// \method deinit()
/// Turn off the DAC, enable other use of pin.
STATIC mp_obj_t pyb_dac_deinit(mp_obj_t self_in) {
pyb_dac_obj_t *self = MP_OBJ_TO_PTR(self_in);
dac_deinit(self->dac_channel);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_dac_deinit_obj, pyb_dac_deinit);
#if defined(TIM6)
/// \method noise(freq)
/// Generate a pseudo-random noise signal. A new random sample is written
/// to the DAC output at the given frequency.
STATIC mp_obj_t pyb_dac_noise(mp_obj_t self_in, mp_obj_t freq) {
pyb_dac_obj_t *self = MP_OBJ_TO_PTR(self_in);
// set TIM6 to trigger the DAC at the given frequency
TIM6_Config(mp_obj_get_int(freq));
// Configure DAC in noise mode with trigger via TIM6
uint32_t cr = DAC_LFSRUNMASK_BITS11_0 | DAC_CR_WAVE1_0 | DAC_TRIGGER_T6_TRGO;
pyb_dac_reconfigure(self, cr, self->outbuf_waveform, 0);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_dac_noise_obj, pyb_dac_noise);
#endif
#if defined(TIM6)
/// \method triangle(freq)
/// Generate a triangle wave. The value on the DAC output changes at
/// the given frequency, and the frequency of the repeating triangle wave
/// itself is 8192 times smaller.
STATIC mp_obj_t pyb_dac_triangle(mp_obj_t self_in, mp_obj_t freq) {
pyb_dac_obj_t *self = MP_OBJ_TO_PTR(self_in);
// set TIM6 to trigger the DAC at the given frequency
TIM6_Config(mp_obj_get_int(freq));
// Configure DAC in full-scale triangle mode with trigger via TIM6
uint32_t cr = DAC_TRIANGLEAMPLITUDE_4095 | DAC_CR_WAVE1_1 | DAC_TRIGGER_T6_TRGO;
pyb_dac_reconfigure(self, cr, self->outbuf_waveform, 0);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_dac_triangle_obj, pyb_dac_triangle);
#endif
/// \method write(value)
/// Direct access to the DAC output (8 bit only at the moment).
STATIC mp_obj_t pyb_dac_write(mp_obj_t self_in, mp_obj_t val) {
pyb_dac_obj_t *self = MP_OBJ_TO_PTR(self_in);
// DAC output is always 12-bit at the hardware level, and we provide support
// for multiple bit "resolutions" simply by shifting the input value.
uint32_t cr = DAC_TRIGGER_NONE;
uint32_t value = mp_obj_get_int(val) << (12 - self->bits);
pyb_dac_reconfigure(self, cr, self->outbuf_single, value);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_dac_write_obj, pyb_dac_write);
#if defined(TIM6)
/// \method write_timed(data, freq, *, mode=DAC.NORMAL)
/// Initiates a burst of RAM to DAC using a DMA transfer.
/// The input data is treated as an array of bytes (8 bit data).
///
/// `freq` can be an integer specifying the frequency to write the DAC
/// samples at, using Timer(6). Or it can be an already-initialised
/// Timer object which is used to trigger the DAC sample. Valid timers
/// are 2, 4, 5, 6, 7 and 8.
///
/// `mode` can be `DAC.NORMAL` or `DAC.CIRCULAR`.
///
// TODO add callback argument, to call when transfer is finished
// TODO add double buffer argument
//
// TODO reconsider API, eg: write_trig(data, *, trig=None, loop=False)
// Then trigger can be timer (preinitialised with desired freq) or pin (extint9),
// and we can reuse the same timer for both DACs (and maybe also ADC) without
// setting the freq twice.
// Can still do 1-liner: dac.write_trig(buf, trig=Timer(6, freq=100), loop=True)
mp_obj_t pyb_dac_write_timed(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_data, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_freq, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_mode, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DMA_NORMAL} },
};
// parse args
pyb_dac_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
// get the data to write
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[0].u_obj, &bufinfo, MP_BUFFER_READ);
uint32_t dac_trigger;
if (mp_obj_is_integer(args[1].u_obj)) {
// set TIM6 to trigger the DAC at the given frequency
TIM6_Config(mp_obj_get_int(args[1].u_obj));
dac_trigger = DAC_TRIGGER_T6_TRGO;
} else {
// set the supplied timer to trigger the DAC (timer should be initialised)
dac_trigger = TIMx_Config(args[1].u_obj);
}
dac_config_channel(self->dac_channel, DAC_CR_DMAEN1 | dac_trigger, self->outbuf_waveform);
const dma_descr_t *tx_dma_descr;
if (self->dac_channel == DAC_CHANNEL_1) {
tx_dma_descr = &dma_DAC_1_TX;
#if !defined(STM32L452xx)
} else {
tx_dma_descr = &dma_DAC_2_TX;
#endif
}
uint32_t align;
if (self->bits == 8) {
align = DAC_ALIGN_8B_R;
} else {
align = DAC_ALIGN_12B_R;
bufinfo.len /= 2;
}
dac_start_dma(self->dac_channel, tx_dma_descr, args[2].u_int, self->bits, align, bufinfo.len, bufinfo.buf);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_dac_write_timed_obj, 1, pyb_dac_write_timed);
#endif
STATIC const mp_rom_map_elem_t pyb_dac_locals_dict_table[] = {
// instance methods
{ MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&pyb_dac_init_obj) },
{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&pyb_dac_deinit_obj) },
{ MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&pyb_dac_write_obj) },
#if defined(TIM6)
{ MP_ROM_QSTR(MP_QSTR_noise), MP_ROM_PTR(&pyb_dac_noise_obj) },
{ MP_ROM_QSTR(MP_QSTR_triangle), MP_ROM_PTR(&pyb_dac_triangle_obj) },
{ MP_ROM_QSTR(MP_QSTR_write_timed), MP_ROM_PTR(&pyb_dac_write_timed_obj) },
#endif
// class constants
{ MP_ROM_QSTR(MP_QSTR_NORMAL), MP_ROM_INT(DMA_NORMAL) },
{ MP_ROM_QSTR(MP_QSTR_CIRCULAR), MP_ROM_INT(DMA_CIRCULAR) },
};
STATIC MP_DEFINE_CONST_DICT(pyb_dac_locals_dict, pyb_dac_locals_dict_table);
MP_DEFINE_CONST_OBJ_TYPE(
pyb_dac_type,
MP_QSTR_DAC,
MP_TYPE_FLAG_NONE,
make_new, pyb_dac_make_new,
print, pyb_dac_print,
locals_dict, &pyb_dac_locals_dict
);
#endif // MICROPY_HW_ENABLE_DAC
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