blob: a01fa5866fb1833d313301092e5d79727a9d5dbe (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
|
#include "ArduinoSerialInterface.h"
#define RECV_STATE_IDLE 0
#define RECV_STATE_HDR_FOUND 1
#define RECV_STATE_LEN1_FOUND 2
#define RECV_STATE_LEN2_FOUND 3
void ArduinoSerialInterface::enable() {
_isEnabled = true;
_state = RECV_STATE_IDLE;
}
void ArduinoSerialInterface::disable() {
_isEnabled = false;
}
bool ArduinoSerialInterface::isConnected() const {
return true; // no way of knowing, so assume yes
}
bool ArduinoSerialInterface::isWriteBusy() const {
return false;
}
size_t ArduinoSerialInterface::writeFrame(const uint8_t src[], size_t len) {
if (len > MAX_FRAME_SIZE) {
// frame is too big!
return 0;
}
uint8_t hdr[3];
hdr[0] = '>';
hdr[1] = (len & 0xFF); // LSB
hdr[2] = (len >> 8); // MSB
_serial->write(hdr, 3);
return _serial->write(src, len);
}
size_t ArduinoSerialInterface::checkRecvFrame(uint8_t dest[]) {
while (_serial->available()) {
int c = _serial->read();
if (c < 0) break;
switch (_state) {
case RECV_STATE_IDLE:
if (c == '<') {
_state = RECV_STATE_HDR_FOUND;
}
break;
case RECV_STATE_HDR_FOUND:
_frame_len = (uint8_t)c; // LSB
_state = RECV_STATE_LEN1_FOUND;
break;
case RECV_STATE_LEN1_FOUND:
_frame_len |= ((uint16_t)c) << 8; // MSB
rx_len = 0;
_state = _frame_len > 0 ? RECV_STATE_LEN2_FOUND : RECV_STATE_IDLE;
break;
default:
if (rx_len < MAX_FRAME_SIZE) {
rx_buf[rx_len] = (uint8_t)c; // rest of frame will be discarded if > MAX
}
rx_len++;
if (rx_len >= _frame_len) { // received a complete frame?
if (_frame_len > MAX_FRAME_SIZE) _frame_len = MAX_FRAME_SIZE; // truncate
memcpy(dest, rx_buf, _frame_len);
_state = RECV_STATE_IDLE; // reset state, for next frame
return _frame_len;
}
}
}
return 0;
}
|
