diff options
| -rw-r--r-- | docs/esp32/quickref.rst | 14 | ||||
| -rw-r--r-- | ports/esp32/Makefile | 1 | ||||
| -rw-r--r-- | ports/esp32/machine_i2c.c | 179 | ||||
| -rw-r--r-- | ports/esp32/mpconfigport.h | 1 |
4 files changed, 192 insertions, 3 deletions
diff --git a/docs/esp32/quickref.rst b/docs/esp32/quickref.rst index 76fe0d9f9..dd85b102b 100644 --- a/docs/esp32/quickref.rst +++ b/docs/esp32/quickref.rst @@ -303,14 +303,22 @@ Hardware SPI has the same methods as Software SPI above:: I2C bus ------- -The I2C driver is implemented in software and works on all pins, -and is accessed via the :ref:`machine.I2C <machine.I2C>` class:: +The I2C driver has both software and hardware implementations, and the two +hardware peripherals have identifiers 0 and 1. Any available output-capable +pins can be used for SCL and SDA. The driver is accessed via the +:ref:`machine.I2C <machine.I2C>` class:: from machine import Pin, I2C - # construct an I2C bus + # construct a software I2C bus i2c = I2C(scl=Pin(5), sda=Pin(4), freq=100000) + # construct a hardware I2C bus + i2c = I2C(0) + i2c = I2C(1, scl=Pin(5), sda=Pin(4), freq=400000) + + i2c.scan() # scan for slave devices + i2c.readfrom(0x3a, 4) # read 4 bytes from slave device with address 0x3a i2c.writeto(0x3a, '12') # write '12' to slave device with address 0x3a diff --git a/ports/esp32/Makefile b/ports/esp32/Makefile index ec6d29695..4ce4e4899 100644 --- a/ports/esp32/Makefile +++ b/ports/esp32/Makefile @@ -181,6 +181,7 @@ SRC_C = \ machine_touchpad.c \ machine_adc.c \ machine_dac.c \ + machine_i2c.c \ machine_pwm.c \ machine_uart.c \ modmachine.c \ diff --git a/ports/esp32/machine_i2c.c b/ports/esp32/machine_i2c.c new file mode 100644 index 000000000..b34d24b16 --- /dev/null +++ b/ports/esp32/machine_i2c.c @@ -0,0 +1,179 @@ +/* + * This file is part of the MicroPython project, http://micropython.org/ + * + * The MIT License (MIT) + * + * Copyright (c) 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 "py/runtime.h" +#include "py/mphal.h" +#include "py/mperrno.h" +#include "extmod/machine_i2c.h" + +#include "driver/i2c.h" + +#define I2C_0_DEFAULT_SCL (GPIO_NUM_18) +#define I2C_0_DEFAULT_SDA (GPIO_NUM_19) +#define I2C_1_DEFAULT_SCL (GPIO_NUM_25) +#define I2C_1_DEFAULT_SDA (GPIO_NUM_26) + +#define I2C_DEFAULT_TIMEOUT_US (10000) // 10ms + +typedef struct _machine_hw_i2c_obj_t { + mp_obj_base_t base; + i2c_port_t port : 8; + gpio_num_t scl : 8; + gpio_num_t sda : 8; +} machine_hw_i2c_obj_t; + +STATIC const mp_obj_type_t machine_hw_i2c_type; +STATIC machine_hw_i2c_obj_t machine_hw_i2c_obj[I2C_NUM_MAX]; + +STATIC void machine_hw_i2c_init(machine_hw_i2c_obj_t *self, uint32_t freq, uint32_t timeout_us, bool first_init) { + if (!first_init) { + i2c_driver_delete(self->port); + } + i2c_config_t conf = { + .mode = I2C_MODE_MASTER, + .sda_io_num = self->sda, + .sda_pullup_en = GPIO_PULLUP_ENABLE, + .scl_io_num = self->scl, + .scl_pullup_en = GPIO_PULLUP_ENABLE, + .master.clk_speed = freq, + }; + i2c_param_config(self->port, &conf); + i2c_set_timeout(self->port, I2C_APB_CLK_FREQ / 1000000 * timeout_us); + i2c_driver_install(self->port, I2C_MODE_MASTER, 0, 0, 0); +} + +int machine_hw_i2c_transfer(mp_obj_base_t *self_in, uint16_t addr, size_t n, mp_machine_i2c_buf_t *bufs, unsigned int flags) { + machine_hw_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); + + i2c_cmd_handle_t cmd = i2c_cmd_link_create(); + i2c_master_start(cmd); + i2c_master_write_byte(cmd, addr << 1 | (flags & MP_MACHINE_I2C_FLAG_READ), true); + + int data_len = 0; + for (; n--; ++bufs) { + if (flags & MP_MACHINE_I2C_FLAG_READ) { + i2c_master_read(cmd, bufs->buf, bufs->len, n == 0 ? I2C_MASTER_LAST_NACK : I2C_MASTER_ACK); + } else { + if (bufs->len != 0) { + i2c_master_write(cmd, bufs->buf, bufs->len, true); + } + } + data_len += bufs->len; + } + + if (flags & MP_MACHINE_I2C_FLAG_STOP) { + i2c_master_stop(cmd); + } + + // TODO proper timeout + esp_err_t err = i2c_master_cmd_begin(self->port, cmd, 100 * (1 + data_len) / portTICK_RATE_MS); + i2c_cmd_link_delete(cmd); + + if (err == ESP_FAIL) { + return -MP_ENODEV; + } else if (err == ESP_ERR_TIMEOUT) { + return -MP_ETIMEDOUT; + } else if (err != ESP_OK) { + return -abs(err); + } + + return data_len; +} + +/******************************************************************************/ +// MicroPython bindings for machine API + +STATIC void machine_hw_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) { + machine_hw_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); + int h, l; + i2c_get_period(self->port, &h, &l); + mp_printf(print, "I2C(%u, scl=%u, sda=%u, freq=%u)", + self->port, self->scl, self->sda, I2C_APB_CLK_FREQ / (h + l)); +} + +mp_obj_t machine_hw_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) { + // Parse args + enum { ARG_id, ARG_scl, ARG_sda, ARG_freq, ARG_timeout }; + static const mp_arg_t allowed_args[] = { + { MP_QSTR_id, MP_ARG_REQUIRED | MP_ARG_OBJ }, + { MP_QSTR_scl, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, + { MP_QSTR_sda, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, + { MP_QSTR_freq, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} }, + { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = I2C_DEFAULT_TIMEOUT_US} }, + }; + mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)]; + mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args); + + // Get I2C bus + mp_int_t i2c_id = mp_obj_get_int(args[ARG_id].u_obj); + if (!(I2C_NUM_0 <= i2c_id && i2c_id < I2C_NUM_MAX)) { + nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "I2C(%d) doesn't exist", i2c_id)); + } + + // Get static peripheral object + machine_hw_i2c_obj_t *self = (machine_hw_i2c_obj_t*)&machine_hw_i2c_obj[i2c_id]; + + bool first_init = false; + if (self->base.type == NULL) { + // Created for the first time, set default pins + self->base.type = &machine_hw_i2c_type; + self->port = i2c_id; + if (self->port == I2C_NUM_0) { + self->scl = I2C_0_DEFAULT_SCL; + self->sda = I2C_0_DEFAULT_SDA; + } else { + self->scl = I2C_1_DEFAULT_SCL; + self->sda = I2C_1_DEFAULT_SDA; + } + first_init = true; + } + + // Set SCL/SDA pins if given + if (args[ARG_scl].u_obj != MP_OBJ_NULL) { + self->scl = mp_hal_get_pin_obj(args[ARG_scl].u_obj); + } + if (args[ARG_sda].u_obj != MP_OBJ_NULL) { + self->sda = mp_hal_get_pin_obj(args[ARG_sda].u_obj); + } + + // Initialise the I2C peripheral + machine_hw_i2c_init(self, args[ARG_freq].u_int, args[ARG_timeout].u_int, first_init); + + return MP_OBJ_FROM_PTR(self); +} + +STATIC const mp_machine_i2c_p_t machine_hw_i2c_p = { + .transfer = machine_hw_i2c_transfer, +}; + +STATIC const mp_obj_type_t machine_hw_i2c_type = { + { &mp_type_type }, + .name = MP_QSTR_I2C, + .print = machine_hw_i2c_print, + .make_new = machine_hw_i2c_make_new, + .protocol = &machine_hw_i2c_p, + .locals_dict = (mp_obj_dict_t*)&mp_machine_soft_i2c_locals_dict, +}; diff --git a/ports/esp32/mpconfigport.h b/ports/esp32/mpconfigport.h index bd19c6bfb..9ffe380fc 100644 --- a/ports/esp32/mpconfigport.h +++ b/ports/esp32/mpconfigport.h @@ -137,6 +137,7 @@ #define MICROPY_PY_MACHINE_PIN_MAKE_NEW mp_pin_make_new #define MICROPY_PY_MACHINE_PULSE (1) #define MICROPY_PY_MACHINE_I2C (1) +#define MICROPY_PY_MACHINE_I2C_MAKE_NEW machine_hw_i2c_make_new #define MICROPY_PY_MACHINE_SPI (1) #define MICROPY_PY_MACHINE_SPI_MSB (0) #define MICROPY_PY_MACHINE_SPI_LSB (1) |