micropython · bskp · Sep 24, 2019 · jimmo · Mar 30, 2020 · bskp
diff --git a/docs/esp32/quickref.rst b/docs/esp32/quickref.rst
@@ -189,6 +189,33 @@ Use the ``machine.PWM`` class::
 
     pwm2 = PWM(Pin(2), freq=20000, duty=512) # create and configure in one go
 
+MCPWM (motor control pulse width modulation)
+--------------------------------------------
+
+MCPWM can be enabled on all output-enabled pins. The API differs slightly from `machine.PWM` to allow explicit timer selection.
+Currently, this implementation only covers basic functionality.  
+
+For more details, see Espressif's `MCPWM
+<https://docs.espressif.com/projects/esp-idf/en/latest/api-reference/peripherals/mcpwm.html>`_ documentation.
+
+
+Use the `esp32.MCPWM` class::
+
+    from machine import Pin
+    from esp32 import MCPWM
+
+    pwm0 = PWM(0)           # Create MCPWM object with timer ID (0..5)
+    pwm0.bind(Pin(5))       # Bind to output Pin. Output starts immediately.
+
+    pwm0.freq(500)          # Set frequency in Hz
+    pwm0.freq()             # Get current frequency
+    pwm0.duty(20)           # Set duty in percent
+    pwm0.duty()             # Get current duty
+
+    pwm0.deinit()           # turn of PWM on pin
+
+
+
 ADC (analog to digital conversion)
 ----------------------------------
 

diff --git a/lib/mbedtls b/lib/mbedtls
diff --git a/ports/esp32/Makefile b/ports/esp32/Makefile
@@ -345,6 +345,7 @@ SRC_C = \
 	esp32_partition.c \
 	esp32_rmt.c \
 	esp32_ulp.c \
+	esp32_mcpwm.c \
 	modesp32.c \
 	espneopixel.c \
 	machine_hw_spi.c \

diff --git a/ports/esp32/esp32_mcpwm.c b/ports/esp32/esp32_mcpwm.c
@@ -0,0 +1,146 @@
+#include "py/nlr.h"
+#include "py/obj.h"
+#include "py/runtime.h"
+#include "py/binary.h"
+
+#include <stdio.h>
+#include "driver/mcpwm.h"
+#include "mphalport.h"
+#include "esp_err.h"
+
+#define MCPWM_CHANNEL_MAX (MCPWM_TIMER_MAX * MCPWM_UNIT_MAX)
+
+typedef struct _mcpwm_obj_t {
+    mp_obj_base_t base;
+    uint8_t id;
+    gpio_num_t pin_a;
+    gpio_num_t pin_b;
+
+    // Derived values for easier IDF API calls.
+    mcpwm_unit_t unit;
+    mcpwm_timer_t timer;
+    mcpwm_io_signals_t sig_a;
+    mcpwm_io_signals_t sig_b;
+} mcpwm_obj_t;
+
+// Forward dec'l
+extern const mp_obj_type_t esp32_mcpwm_type;
+STATIC mp_obj_t _mcpwm_deinit(mp_obj_t self_in);
+STATIC mp_obj_t _mcpwm_duty(size_t n_args, const mp_obj_t *args);
+STATIC mp_obj_t _mcpwm_freq(size_t n_args, const mp_obj_t *args);
+
+STATIC mp_obj_t mcpwm_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    mp_arg_check_num(n_args, n_kw, 1, 3, true);
+
+    int block_id = mp_obj_get_int(args[0]);
+    if (block_id >= MCPWM_CHANNEL_MAX) {
+        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "bad timer id requested: %d (0~5 allowed)", block_id));
+    }
+
+    // create PWM object from the given timer block
+    mcpwm_obj_t *self = m_new_obj(mcpwm_obj_t);
+    self->base.type = &esp32_mcpwm_type;
+    self->id = block_id;
+
+    self->timer = self->id % MCPWM_TIMER_MAX;
+    self->unit = self->id / MCPWM_TIMER_MAX;
+    self->sig_a = self->timer * 2;  // even numbers -> A operators
+    self->sig_b = self->timer * 2 + 1;  // odd numbers -> B operators
+
+    mcpwm_config_t config = {
+        .frequency = 1000,  // frequency = 1kHz
+        .cmpr_a = 50,       // duty A = 50%
+        .cmpr_b = 20,       // duty B = 20%
+        .counter_mode = MCPWM_UP_COUNTER,
+        .duty_mode = MCPWM_DUTY_MODE_0
+    };
+
+    mcpwm_init(self->unit, self->timer, &config);
+    mp_obj_t self_out = MP_OBJ_FROM_PTR(self);
+
+    return self_out;
+    }
+
+
+STATIC void mcpwm_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
+    mcpwm_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    mp_printf(print, "MCPWM(ID=%u. ", self->id);
+    mp_printf(print, "pin=%u, ", self->pin_a);
+    float duty = mcpwm_get_duty(self->unit, self->timer, MCPWM_OPR_A);
+    int freq = mcpwm_get_frequency(self->unit, self->timer);
+    mp_printf(print, "freq=%uHz, duty=%.1f%%", freq, duty);
+    mp_printf(print, ")");
+}
+
+
+// BIND
+STATIC mp_obj_t _mcpwm_bind(mp_obj_t self_in, mp_obj_t pin) {
+    mcpwm_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    gpio_num_t pin_id = machine_pin_get_id(pin);
+    mcpwm_gpio_init(self->unit, self->sig_a, pin_id);
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_2(mcpwm_bind_obj,  _mcpwm_bind);
+
+
+// DEINIT
+STATIC mp_obj_t _mcpwm_deinit(mp_obj_t self_in) {
+    mcpwm_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    mcpwm_stop(self->unit, self->timer);
+    //mcpwm_set_signal_low(self->unit, self->timer, MCPWM_OPR_A);
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(mcpwm_deinit_obj, _mcpwm_deinit);
+
+
+// FREQ
+STATIC mp_obj_t _mcpwm_freq(size_t n_args, const mp_obj_t *args) {
+    mcpwm_obj_t *self = MP_OBJ_TO_PTR(args[0]);
+
+    if (n_args == 1) {
+        // get
+        return MP_OBJ_NEW_SMALL_INT(mcpwm_get_frequency(self->unit, self->timer));
+    }
+
+    // set
+    int tval = mp_obj_get_int(args[1]);
+    mcpwm_set_frequency(self->unit, self->timer, tval);
+
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mcpwm_freq_obj, 1, 2, _mcpwm_freq);
+
+
+// DUTY
+STATIC mp_obj_t _mcpwm_duty(size_t n_args, const mp_obj_t *args) {
+    mcpwm_obj_t *self = MP_OBJ_TO_PTR(args[0]);
+
+    if (n_args == 1) {
+        // get
+        return mp_obj_new_float(mcpwm_get_duty(self->unit, self->timer, MCPWM_OPR_A));
+    }
+
+    // set
+    float tval = mp_obj_get_float(args[1]);
+    mcpwm_set_duty(self->unit, self->timer, MCPWM_OPR_A, tval);
+
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mcpwm_duty_obj, 1, 2, _mcpwm_duty);
+
+
+STATIC const mp_rom_map_elem_t mcpwm_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR_bind), MP_ROM_PTR(&mcpwm_bind_obj) },
+    { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&mcpwm_deinit_obj) },
+    { MP_ROM_QSTR(MP_QSTR_duty), MP_ROM_PTR(&mcpwm_duty_obj) },
+    { MP_ROM_QSTR(MP_QSTR_freq), MP_ROM_PTR(&mcpwm_freq_obj) },
+};
+STATIC MP_DEFINE_CONST_DICT(mcpwm_locals_dict, mcpwm_locals_dict_table);
+
+const mp_obj_type_t esp32_mcpwm_type = {
+    { &mp_type_type },
+    .name = MP_QSTR_MCPWM,
+    .print = mcpwm_print,
+    .make_new = mcpwm_make_new,
+    .locals_dict = (mp_obj_dict_t *)&mcpwm_locals_dict,
+};
diff --git a/ports/esp32/modesp32.c b/ports/esp32/modesp32.c
@@ -157,6 +157,7 @@ STATIC const mp_rom_map_elem_t esp32_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_Partition), MP_ROM_PTR(&esp32_partition_type) },
     { MP_ROM_QSTR(MP_QSTR_RMT), MP_ROM_PTR(&esp32_rmt_type) },
     { MP_ROM_QSTR(MP_QSTR_ULP), MP_ROM_PTR(&esp32_ulp_type) },
+    { MP_ROM_QSTR(MP_QSTR_MCPWM), MP_ROM_PTR(&esp32_mcpwm_type) },
 
     { MP_ROM_QSTR(MP_QSTR_WAKEUP_ALL_LOW), MP_ROM_FALSE },
     { MP_ROM_QSTR(MP_QSTR_WAKEUP_ANY_HIGH), MP_ROM_TRUE },

diff --git a/ports/esp32/modesp32.h b/ports/esp32/modesp32.h
@@ -29,5 +29,6 @@
 extern const mp_obj_type_t esp32_partition_type;
 extern const mp_obj_type_t esp32_rmt_type;
 extern const mp_obj_type_t esp32_ulp_type;
+extern const mp_obj_type_t esp32_mcpwm_type;
 
 #endif // MICROPY_INCLUDED_ESP32_MODESP32_H