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dpgeorgedpgeorge
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esp8266: Implement UART.read functionality.
1 parent 7652ab7 commit d46bea9

1 file changed

Lines changed: 57 additions & 18 deletions

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‎esp8266/modpybuart.c‎

Lines changed: 57 additions & 18 deletions
Original file line numberDiff line numberDiff line change
@@ -36,34 +36,50 @@
3636
#include "py/stream.h"
3737
#include "modpyb.h"
3838

39+
// baudrate is currently fixed to this value
40+
#define UART_BAUDRATE (115200)
41+
3942
typedef struct _pyb_uart_obj_t {
4043
mp_obj_base_t base;
4144
uint8_t uart_id;
45+
uint16_t timeout; // timeout waiting for first char (in ms)
46+
uint16_t timeout_char; // timeout waiting between chars (in ms)
4247
} pyb_uart_obj_t;
4348

4449
/******************************************************************************/
4550
// MicroPython bindings for UART
4651

4752
STATIC void pyb_uart_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
4853
pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
49-
mp_printf(print, "UART(%u)", self->uart_id);
54+
mp_printf(print, "UART(%u, baudrate=%u, timeout=%u, timeout_char=%u)",
55+
self->uart_id, UART_BAUDRATE, self->timeout, self->timeout_char);
5056
}
5157

5258
STATIC void pyb_uart_init_helper(pyb_uart_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
53-
/*
54-
enum { ARG_baudrate, ARG_bits, ARG_parity, ARG_stop };
59+
enum { ARG_timeout, ARG_timeout_char };
5560
static const mp_arg_t allowed_args[] = {
56-
{ MP_QSTR_baudrate, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 9600} },
57-
{ MP_QSTR_bits, MP_ARG_INT, {.u_int = 8} },
58-
{ MP_QSTR_parity, MP_ARG_OBJ, {.u_obj = mp_const_none} },
59-
{ MP_QSTR_stop, MP_ARG_INT, {.u_int = 1} },
60-
{ MP_QSTR_tx, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
61-
{ MP_QSTR_rx, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
61+
//{ MP_QSTR_baudrate, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 9600} },
62+
//{ MP_QSTR_bits, MP_ARG_INT, {.u_int = 8} },
63+
//{ MP_QSTR_parity, MP_ARG_OBJ, {.u_obj = mp_const_none} },
64+
//{ MP_QSTR_stop, MP_ARG_INT, {.u_int = 1} },
65+
//{ MP_QSTR_tx, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
66+
//{ MP_QSTR_rx, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
67+
{ MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
68+
{ MP_QSTR_timeout_char, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
6269
};
6370
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
6471
mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
65-
*/
66-
// not implemented
72+
73+
// set timeout
74+
self->timeout = args[ARG_timeout].u_int;
75+
76+
// set timeout_char
77+
// make sure it is at least as long as a whole character (13 bits to be safe)
78+
self->timeout_char = args[ARG_timeout_char].u_int;
79+
uint32_t min_timeout_char = 13000 / UART_BAUDRATE + 1;
80+
if (self->timeout_char < min_timeout_char) {
81+
self->timeout_char = min_timeout_char;
82+
}
6783
}
6884

6985
STATIC mp_obj_t pyb_uart_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
@@ -80,12 +96,10 @@ STATIC mp_obj_t pyb_uart_make_new(const mp_obj_type_t *type, size_t n_args, size
8096
self->base.type = &pyb_uart_type;
8197
self->uart_id = uart_id;
8298

83-
if (n_args > 1 || n_kw > 0) {
84-
// init the peripheral
85-
mp_map_t kw_args;
86-
mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
87-
pyb_uart_init_helper(self, n_args - 1, args + 1, &kw_args);
88-
}
99+
// init the peripheral
100+
mp_map_t kw_args;
101+
mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
102+
pyb_uart_init_helper(self, n_args - 1, args + 1, &kw_args);
89103

90104
return MP_OBJ_FROM_PTR(self);
91105
}
@@ -109,7 +123,32 @@ STATIC const mp_rom_map_elem_t pyb_uart_locals_dict_table[] = {
109123
STATIC MP_DEFINE_CONST_DICT(pyb_uart_locals_dict, pyb_uart_locals_dict_table);
110124

111125
STATIC mp_uint_t pyb_uart_read(mp_obj_t self_in, void *buf_in, mp_uint_t size, int *errcode) {
112-
mp_not_implemented("reading from UART");
126+
pyb_uart_obj_t *self = MP_OBJ_TO_PTR(self_in);
127+
128+
if (self->uart_id == 1) {
129+
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_OSError, "UART(1) can't read"));
130+
}
131+
132+
// make sure we want at least 1 char
133+
if (size == 0) {
134+
return 0;
135+
}
136+
137+
// wait for first char to become available
138+
if (!uart_rx_wait(self->timeout * 1000)) {
139+
*errcode = EAGAIN;
140+
return MP_STREAM_ERROR;
141+
}
142+
143+
// read the data
144+
uint8_t *buf = buf_in;
145+
for (;;) {
146+
*buf++ = uart_rx_char();
147+
if (--size == 0 || !uart_rx_wait(self->timeout_char * 1000)) {
148+
// return number of bytes read
149+
return buf - (uint8_t*)buf_in;
150+
}
151+
}
113152
}
114153

115154
STATIC mp_uint_t pyb_uart_write(mp_obj_t self_in, const void *buf_in, mp_uint_t size, int *errcode) {

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