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stmhal: Add I2C.scan method, to scan all devices on the bus.

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Simple way to find the address of an attached I2C device.
This commit is contained in:
Damien George 2014-04-15 19:24:13 +01:00
parent f6d25ecf7b
commit e95da5b784
2 changed files with 24 additions and 2 deletions
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25
stmhal/i2c.c
View File

@ -98,14 +98,13 @@ STATIC mp_obj_t pyb_i2c_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const
return (mp_obj_t)i2c_obj; return (mp_obj_t)i2c_obj;
} }
// Check if an I2C device responds to the given address.
STATIC mp_obj_t pyb_i2c_is_ready(mp_obj_t self_in, mp_obj_t i2c_addr_o) { 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; pyb_i2c_obj_t *self = self_in;
machine_uint_t i2c_addr = mp_obj_get_int(i2c_addr_o) << 1; machine_uint_t i2c_addr = mp_obj_get_int(i2c_addr_o) << 1;
//printf("IsDeviceReady\n");
for (int i = 0; i < 10; i++) { for (int i = 0; i < 10; i++) {
HAL_StatusTypeDef status = HAL_I2C_IsDeviceReady(self->i2c_handle, i2c_addr, 10, 200); HAL_StatusTypeDef status = HAL_I2C_IsDeviceReady(self->i2c_handle, i2c_addr, 10, 200);
//printf(" got %d\n", status);
if (status == HAL_OK) { if (status == HAL_OK) {
return mp_const_true; return mp_const_true;
} }
@ -116,6 +115,27 @@ STATIC mp_obj_t pyb_i2c_is_ready(mp_obj_t self_in, mp_obj_t i2c_addr_o) {
STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_i2c_is_ready_obj, pyb_i2c_is_ready); STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_i2c_is_ready_obj, pyb_i2c_is_ready);
// Scan all I2C addresses from 0x01 to 0x7f and return a list of those that respond.
STATIC mp_obj_t pyb_i2c_scan(mp_obj_t self_in) {
pyb_i2c_obj_t *self = self_in;
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_handle, 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);
STATIC mp_obj_t pyb_i2c_mem_read(uint n_args, const mp_obj_t *args) { STATIC mp_obj_t pyb_i2c_mem_read(uint n_args, const mp_obj_t *args) {
pyb_i2c_obj_t *self = args[0]; pyb_i2c_obj_t *self = args[0];
machine_uint_t i2c_addr = mp_obj_get_int(args[1]) << 1; machine_uint_t i2c_addr = mp_obj_get_int(args[1]) << 1;
@ -166,6 +186,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_i2c_mem_write_obj, 4, 4, pyb_i2c_
STATIC const mp_map_elem_t pyb_i2c_locals_dict_table[] = { STATIC const mp_map_elem_t pyb_i2c_locals_dict_table[] = {
{ MP_OBJ_NEW_QSTR(MP_QSTR_is_ready), (mp_obj_t)&pyb_i2c_is_ready_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_mem_read), (mp_obj_t)&pyb_i2c_mem_read_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 }, { MP_OBJ_NEW_QSTR(MP_QSTR_mem_write), (mp_obj_t)&pyb_i2c_mem_write_obj },
}; };

1
stmhal/qstrdefsport.h
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@ -82,6 +82,7 @@ Q(MODE_EVT_RISING_FALLING)
// for I2C object // for I2C object
Q(I2C) Q(I2C)
Q(is_ready) Q(is_ready)
Q(scan)
Q(mem_read) Q(mem_read)
Q(mem_write) Q(mem_write)