#include #include #include "stm32f4xx_hal.h" #include "mpconfig.h" #include "nlr.h" #include "misc.h" #include "qstr.h" #include "obj.h" #include "runtime.h" #include "pin.h" #include "genhdr/pins.h" #include "bufhelper.h" #include "i2c.h" /// \moduleref pyb /// \class I2C - a two-wire serial protocol /// /// I2C is a two-wire protocol for communicating between devices. At the physical /// level it consists of 2 wires: SCL and SDA, the clock and data lines respectively. /// /// I2C objects are created attached to a specific bus. They can be initialised /// when created, or initialised later on: /// /// from pyb import I2C /// /// i2c = I2C(1) # create on bus 1 /// i2c = I2C(1, I2C.MASTER) # create and init as a master /// i2c.init(I2C.MASTER, baudrate=20000) # init as a master /// i2c.init(I2C.SLAVE, addr=0x42) # init as a slave with given address /// i2c.deinit() # turn off the peripheral /// /// Printing the i2c object gives you information about its configuration. /// /// Basic methods for slave are send and recv: /// /// i2c.send('abc') # send 3 bytes /// i2c.send(0x42) # send a single byte, given by the number /// data = i2c.recv(3) # receive 3 bytes /// /// To receive inplace, first create a bytearray: /// /// data = bytearray(3) # create a buffer /// i2c.recv(data) # receive 3 bytes, writing them into data /// /// You can specify a timeout (in ms): /// /// i2c.send(b'123', timeout=2000) # timout after 2 seconds /// /// A master must specify the recipient's address: /// /// i2c.init(I2C.MASTER) /// i2c.send('123', 0x42) # send 3 bytes to slave with address 0x42 /// i2c.send(b'456', addr=0x42) # keyword for address /// /// Master also has other methods: /// /// i2c.is_ready(0x42) # check if slave 0x42 is ready /// i2c.scan() # scan for slaves on the bus, returning /// # a list of valid addresses /// i2c.mem_read(3, 0x42, 2) # read 3 bytes from memory of slave 0x42, /// # starting at address 2 in the slave /// i2c.mem_write('abc', 0x42, 2, timeout=1000) #define PYB_I2C_MASTER (0) #define PYB_I2C_SLAVE (1) #if MICROPY_HW_ENABLE_I2C1 I2C_HandleTypeDef I2CHandle1 = {.Instance = NULL}; #endif I2C_HandleTypeDef I2CHandle2 = {.Instance = NULL}; void i2c_init0(void) { // reset the I2C1 handles #if MICROPY_HW_ENABLE_I2C1 memset(&I2CHandle1, 0, sizeof(I2C_HandleTypeDef)); I2CHandle1.Instance = I2C1; #endif memset(&I2CHandle2, 0, sizeof(I2C_HandleTypeDef)); I2CHandle2.Instance = I2C2; } void i2c_init(I2C_HandleTypeDef *i2c) { // init the GPIO lines GPIO_InitTypeDef GPIO_InitStructure; GPIO_InitStructure.Mode = GPIO_MODE_AF_OD; GPIO_InitStructure.Speed = GPIO_SPEED_FAST; GPIO_InitStructure.Pull = GPIO_NOPULL; // have external pull-up resistors on both lines const pin_obj_t *pins[2]; if (0) { #if MICROPY_HW_ENABLE_I2C1 } else if (i2c == &I2CHandle1) { // X-skin: X9=PB6=SCL, X10=PB7=SDA pins[0] = &pin_B6; pins[1] = &pin_B7; GPIO_InitStructure.Alternate = GPIO_AF4_I2C1; // enable the I2C clock __I2C1_CLK_ENABLE(); #endif } else if (i2c == &I2CHandle2) { // Y-skin: Y9=PB10=SCL, Y10=PB11=SDA pins[0] = &pin_B10; pins[1] = &pin_B11; GPIO_InitStructure.Alternate = GPIO_AF4_I2C2; // enable the I2C clock __I2C2_CLK_ENABLE(); } else { // I2C does not exist for this board (shouldn't get here, should be checked by caller) return; } // init the GPIO lines for (uint i = 0; i < 2; i++) { GPIO_InitStructure.Pin = pins[i]->pin_mask; HAL_GPIO_Init(pins[i]->gpio, &GPIO_InitStructure); } // init the I2C device if (HAL_I2C_Init(i2c) != HAL_OK) { // init error // TODO should raise an exception, but this function is not necessarily going to be // called via Python, so may not be properly wrapped in an NLR handler printf("HardwareError: HAL_I2C_Init failed\n"); return; } } void i2c_deinit(I2C_HandleTypeDef *i2c) { HAL_I2C_DeInit(i2c); if (0) { #if MICROPY_HW_ENABLE_I2C1 } else if (i2c->Instance == I2C1) { __I2C1_FORCE_RESET(); __I2C1_RELEASE_RESET(); __I2C1_CLK_DISABLE(); #endif } else if (i2c->Instance == I2C2) { __I2C2_FORCE_RESET(); __I2C2_RELEASE_RESET(); __I2C2_CLK_DISABLE(); } } /******************************************************************************/ /* Micro Python bindings */ typedef struct _pyb_i2c_obj_t { mp_obj_base_t base; I2C_HandleTypeDef *i2c; } pyb_i2c_obj_t; STATIC inline bool in_master_mode(pyb_i2c_obj_t *self) { return self->i2c->Init.OwnAddress1 == PYB_I2C_MASTER_ADDRESS; } STATIC const pyb_i2c_obj_t pyb_i2c_obj[] = { #if MICROPY_HW_ENABLE_I2C1 {{&pyb_i2c_type}, &I2CHandle1}, #else {{&pyb_i2c_type}, NULL}, #endif {{&pyb_i2c_type}, &I2CHandle2} }; STATIC void pyb_i2c_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) { pyb_i2c_obj_t *self = self_in; uint i2c_num; if (self->i2c->Instance == I2C1) { i2c_num = 1; } else { i2c_num = 2; } if (self->i2c->State == HAL_I2C_STATE_RESET) { print(env, "I2C(%u)", i2c_num); } else { if (in_master_mode(self)) { print(env, "I2C(%u, I2C.MASTER, baudrate=%u)", i2c_num, self->i2c->Init.ClockSpeed); } else { print(env, "I2C(%u, I2C.SLAVE, addr=0x%02x)", i2c_num, (self->i2c->Instance->OAR1 >> 1) & 0x7f); } } } /// \method init(mode, *, addr=0x12, baudrate=400000, gencall=False) /// /// Initialise the I2C bus with the given parameters: /// /// - `mode` must be either `I2C.MASTER` or `I2C.SLAVE` /// - `addr` is the 7-bit address (only sensible for a slave) /// - `baudrate` is the SCL clock rate (only sensible for a master) /// - `gencall` is whether to support general call mode STATIC const mp_arg_t pyb_i2c_init_args[] = { { MP_QSTR_mode, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} }, { MP_QSTR_addr, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0x12} }, { MP_QSTR_baudrate, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} }, { MP_QSTR_gencall, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false} }, }; #define PYB_I2C_INIT_NUM_ARGS ARRAY_SIZE(pyb_i2c_init_args) STATIC mp_obj_t pyb_i2c_init_helper(const pyb_i2c_obj_t *self, uint n_args, const mp_obj_t *args, mp_map_t *kw_args) { // parse args mp_arg_val_t vals[PYB_I2C_INIT_NUM_ARGS]; mp_arg_parse_all(n_args, args, kw_args, PYB_I2C_INIT_NUM_ARGS, pyb_i2c_init_args, vals); // set the I2C configuration values I2C_InitTypeDef *init = &self->i2c->Init; if (vals[0].u_int == PYB_I2C_MASTER) { // use a special address to indicate we are a master init->OwnAddress1 = PYB_I2C_MASTER_ADDRESS; } else { init->OwnAddress1 = (vals[1].u_int << 1) & 0xfe; } init->AddressingMode = I2C_ADDRESSINGMODE_7BIT; init->ClockSpeed = MIN(vals[2].u_int, 400000); init->DualAddressMode = I2C_DUALADDRESS_DISABLED; init->DutyCycle = I2C_DUTYCYCLE_16_9; init->GeneralCallMode = vals[3].u_bool ? I2C_GENERALCALL_ENABLED : I2C_GENERALCALL_DISABLED; init->NoStretchMode = I2C_NOSTRETCH_DISABLED; init->OwnAddress2 = 0xfe; // unused // init the I2C bus i2c_init(self->i2c); return mp_const_none; } /// \classmethod \constructor(bus, ...) /// /// Construct an I2C object on the given bus. `bus` can be 1 or 2. /// With no additional parameters, the I2C object is created but not /// initialised (it has the settings from the last initialisation of /// the bus, if any). If extra arguments are given, the bus is initialised. /// See `init` for parameters of initialisation. STATIC mp_obj_t pyb_i2c_make_new(mp_obj_t type_in, uint n_args, uint 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 i2c number machine_int_t i2c_id = mp_obj_get_int(args[0]) - 1; // check i2c number if (!(0 <= i2c_id && i2c_id < ARRAY_SIZE(pyb_i2c_obj) && pyb_i2c_obj[i2c_id].i2c != NULL)) { nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "I2C bus %d does not exist", i2c_id + 1)); } // get I2C object const pyb_i2c_obj_t *i2c_obj = &pyb_i2c_obj[i2c_id]; if (n_args > 1 || n_kw > 0) { // start the peripheral mp_map_t kw_args; mp_map_init_fixed_table(&kw_args, n_kw, args + n_args); pyb_i2c_init_helper(i2c_obj, n_args - 1, args + 1, &kw_args); } return (mp_obj_t)i2c_obj; } STATIC mp_obj_t pyb_i2c_init(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) { return pyb_i2c_init_helper(args[0], n_args - 1, args + 1, kw_args); } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_init_obj, 1, pyb_i2c_init); /// \method deinit() /// Turn off the I2C bus. STATIC mp_obj_t pyb_i2c_deinit(mp_obj_t self_in) { pyb_i2c_obj_t *self = self_in; i2c_deinit(self->i2c); return mp_const_none; } STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_i2c_deinit_obj, pyb_i2c_deinit); /// \method is_ready(addr) /// Check if an I2C device responds to the given address. Only valid when in master mode. STATIC mp_obj_t pyb_i2c_is_ready(mp_obj_t self_in, mp_obj_t i2c_addr_o) { pyb_i2c_obj_t *self = self_in; if (!in_master_mode(self)) { nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "I2C must be a master")); } machine_uint_t i2c_addr = mp_obj_get_int(i2c_addr_o) << 1; for (int i = 0; i < 10; i++) { HAL_StatusTypeDef status = HAL_I2C_IsDeviceReady(self->i2c, i2c_addr, 10, 200); if (status == HAL_OK) { return mp_const_true; } } return mp_const_false; } STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_i2c_is_ready_obj, pyb_i2c_is_ready); /// \method scan() /// Scan all I2C addresses from 0x01 to 0x7f and return a list of those that respond. /// Only valid when in master mode. STATIC mp_obj_t pyb_i2c_scan(mp_obj_t self_in) { pyb_i2c_obj_t *self = self_in; if (!in_master_mode(self)) { nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "I2C must be a master")); } mp_obj_t list = mp_obj_new_list(0, NULL); for (uint addr = 1; addr <= 127; addr++) { for (int i = 0; i < 10; i++) { HAL_StatusTypeDef status = HAL_I2C_IsDeviceReady(self->i2c, addr << 1, 10, 200); if (status == HAL_OK) { mp_obj_list_append(list, mp_obj_new_int(addr)); break; } } } return list; } STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_i2c_scan_obj, pyb_i2c_scan); /// \method send(send, addr=0x00, timeout=5000) /// Send data on the bus: /// /// - `send` is the data to send (an integer to send, or a buffer object) /// - `addr` is the address to send to (only required in master mode) /// - `timeout` is the timeout in milliseconds to wait for the send /// /// Return value: `None`. STATIC const mp_arg_t pyb_i2c_send_args[] = { { MP_QSTR_send, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, { MP_QSTR_addr, MP_ARG_INT, {.u_int = PYB_I2C_MASTER_ADDRESS} }, { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 5000} }, }; #define PYB_I2C_SEND_NUM_ARGS ARRAY_SIZE(pyb_i2c_send_args) STATIC mp_obj_t pyb_i2c_send(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) { pyb_i2c_obj_t *self = args[0]; // parse args mp_arg_val_t vals[PYB_I2C_SEND_NUM_ARGS]; mp_arg_parse_all(n_args - 1, args + 1, kw_args, PYB_I2C_SEND_NUM_ARGS, pyb_i2c_send_args, vals); // get the buffer to send from mp_buffer_info_t bufinfo; uint8_t data[1]; pyb_buf_get_for_send(vals[0].u_obj, &bufinfo, data); // send the data HAL_StatusTypeDef status; if (in_master_mode(self)) { if (vals[1].u_int == PYB_I2C_MASTER_ADDRESS) { nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "addr argument required")); } machine_uint_t i2c_addr = vals[1].u_int << 1; status = HAL_I2C_Master_Transmit(self->i2c, i2c_addr, bufinfo.buf, bufinfo.len, vals[2].u_int); } else { status = HAL_I2C_Slave_Transmit(self->i2c, bufinfo.buf, bufinfo.len, vals[2].u_int); } if (status != HAL_OK) { // TODO really need a HardwareError object, or something nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_Exception, "HAL_I2C_xxx_Transmit failed with code %d", status)); } return mp_const_none; } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_send_obj, 1, pyb_i2c_send); /// \method recv(send, addr=0x00, timeout=5000) /// /// Receive data on the bus: /// /// - `recv` can be an integer, which is the number of bytes to receive, /// or a mutable buffer, which will be filled with received bytes /// - `addr` is the address to receive from (only required in master mode) /// - `timeout` is the timeout in milliseconds to wait for the receive /// /// Return value: if `recv` is an integer then a new buffer of the bytes received, /// otherwise the same buffer that was passed in to `recv`. STATIC const mp_arg_t pyb_i2c_recv_args[] = { { MP_QSTR_recv, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, { MP_QSTR_addr, MP_ARG_INT, {.u_int = PYB_I2C_MASTER_ADDRESS} }, { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 5000} }, }; #define PYB_I2C_RECV_NUM_ARGS ARRAY_SIZE(pyb_i2c_recv_args) STATIC mp_obj_t pyb_i2c_recv(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) { pyb_i2c_obj_t *self = args[0]; // parse args mp_arg_val_t vals[PYB_I2C_RECV_NUM_ARGS]; mp_arg_parse_all(n_args - 1, args + 1, kw_args, PYB_I2C_RECV_NUM_ARGS, pyb_i2c_recv_args, vals); // get the buffer to receive into mp_buffer_info_t bufinfo; mp_obj_t o_ret = pyb_buf_get_for_recv(vals[0].u_obj, &bufinfo); // receive the data HAL_StatusTypeDef status; if (in_master_mode(self)) { if (vals[1].u_int == PYB_I2C_MASTER_ADDRESS) { nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "addr argument required")); } machine_uint_t i2c_addr = vals[1].u_int << 1; status = HAL_I2C_Master_Receive(self->i2c, i2c_addr, bufinfo.buf, bufinfo.len, vals[2].u_int); } else { status = HAL_I2C_Slave_Receive(self->i2c, bufinfo.buf, bufinfo.len, vals[2].u_int); } if (status != HAL_OK) { // TODO really need a HardwareError object, or something nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_Exception, "HAL_I2C_xxx_Receive failed with code %d", status)); } // return the received data if (o_ret == MP_OBJ_NULL) { return vals[0].u_obj; } else { return mp_obj_str_builder_end(o_ret); } } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_recv_obj, 1, pyb_i2c_recv); /// \method mem_read(data, addr, memaddr, timeout=5000) /// /// Read from the memory of an I2C device: /// /// - `data` can be an integer or a buffer to read into /// - `addr` is the I2C device address /// - `memaddr` is the memory location within the I2C device /// - `timeout` is the timeout in milliseconds to wait for the read /// /// Returns the read data. /// This is only valid in master mode. STATIC const mp_arg_t pyb_i2c_mem_read_args[] = { { MP_QSTR_data, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, { MP_QSTR_addr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} }, { MP_QSTR_memaddr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} }, { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 5000} }, }; #define PYB_I2C_MEM_READ_NUM_ARGS ARRAY_SIZE(pyb_i2c_mem_read_args) STATIC mp_obj_t pyb_i2c_mem_read(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) { pyb_i2c_obj_t *self = args[0]; if (!in_master_mode(self)) { nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "I2C must be a master")); } // parse args mp_arg_val_t vals[PYB_I2C_MEM_READ_NUM_ARGS]; mp_arg_parse_all(n_args - 1, args + 1, kw_args, PYB_I2C_MEM_READ_NUM_ARGS, pyb_i2c_mem_read_args, vals); // get the buffer to read into mp_buffer_info_t bufinfo; mp_obj_t o_ret = pyb_buf_get_for_recv(vals[0].u_obj, &bufinfo); // get the addresses machine_uint_t i2c_addr = vals[1].u_int << 1; machine_uint_t mem_addr = vals[2].u_int; HAL_StatusTypeDef status = HAL_I2C_Mem_Read(self->i2c, i2c_addr, mem_addr, I2C_MEMADD_SIZE_8BIT, bufinfo.buf, bufinfo.len, vals[3].u_int); if (status != HAL_OK) { // TODO really need a HardwareError object, or something nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_Exception, "HAL_I2C_Mem_Read failed with code %d", status)); } // return the read data if (o_ret == MP_OBJ_NULL) { return vals[0].u_obj; } else { return mp_obj_str_builder_end(o_ret); } } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_mem_read_obj, 1, pyb_i2c_mem_read); /// \method mem_write(data, addr, memaddr, timeout=5000) /// /// Write to the memory of an I2C device: /// /// - `data` can be an integer or a buffer to write from /// - `addr` is the I2C device address /// - `memaddr` is the memory location within the I2C device /// - `timeout` is the timeout in milliseconds to wait for the write /// /// Returns `None`. /// This is only valid in master mode. STATIC mp_obj_t pyb_i2c_mem_write(uint n_args, const mp_obj_t *args, mp_map_t *kw_args) { pyb_i2c_obj_t *self = args[0]; if (!in_master_mode(self)) { nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "I2C must be a master")); } // parse args (same as mem_read) mp_arg_val_t vals[PYB_I2C_MEM_READ_NUM_ARGS]; mp_arg_parse_all(n_args - 1, args + 1, kw_args, PYB_I2C_MEM_READ_NUM_ARGS, pyb_i2c_mem_read_args, vals); // get the buffer to write from mp_buffer_info_t bufinfo; uint8_t data[1]; pyb_buf_get_for_send(vals[0].u_obj, &bufinfo, data); // get the addresses machine_uint_t i2c_addr = vals[1].u_int << 1; machine_uint_t mem_addr = vals[2].u_int; HAL_StatusTypeDef status = HAL_I2C_Mem_Write(self->i2c, i2c_addr, mem_addr, I2C_MEMADD_SIZE_8BIT, bufinfo.buf, bufinfo.len, vals[3].u_int); if (status != HAL_OK) { // TODO really need a HardwareError object, or something nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_Exception, "HAL_I2C_Mem_Write failed with code %d", status)); } return mp_const_none; } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_i2c_mem_write_obj, 1, pyb_i2c_mem_write); STATIC const mp_map_elem_t pyb_i2c_locals_dict_table[] = { // instance methods { MP_OBJ_NEW_QSTR(MP_QSTR_init), (mp_obj_t)&pyb_i2c_init_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_deinit), (mp_obj_t)&pyb_i2c_deinit_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_is_ready), (mp_obj_t)&pyb_i2c_is_ready_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_scan), (mp_obj_t)&pyb_i2c_scan_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_send), (mp_obj_t)&pyb_i2c_send_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_recv), (mp_obj_t)&pyb_i2c_recv_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_mem_read), (mp_obj_t)&pyb_i2c_mem_read_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_mem_write), (mp_obj_t)&pyb_i2c_mem_write_obj }, // class constants /// \constant MASTER - for initialising the bus to master mode /// \constant SLAVE - for initialising the bus to slave mode { MP_OBJ_NEW_QSTR(MP_QSTR_MASTER), MP_OBJ_NEW_SMALL_INT(PYB_I2C_MASTER) }, { MP_OBJ_NEW_QSTR(MP_QSTR_SLAVE), MP_OBJ_NEW_SMALL_INT(PYB_I2C_SLAVE) }, }; STATIC MP_DEFINE_CONST_DICT(pyb_i2c_locals_dict, pyb_i2c_locals_dict_table); const mp_obj_type_t pyb_i2c_type = { { &mp_type_type }, .name = MP_QSTR_I2C, .print = pyb_i2c_print, .make_new = pyb_i2c_make_new, .locals_dict = (mp_obj_t)&pyb_i2c_locals_dict, };