diff options
| -rw-r--r-- | packet.c | 32 | ||||
| -rw-r--r-- | packet_states.h | 8 |
2 files changed, 20 insertions, 20 deletions
@@ -471,32 +471,29 @@ static void nextstate(struct gps_device_t *session, unsigned char c) session->packet_state = GROUND_STATE; break; case ITALK_LEADER_2: - session->packet_length = (size_t)(c << 8); - session->packet_state = ITALK_LENGTH_1; + session->packet_length = (size_t)(c & 0xff); + session->packet_state = ITALK_LENGTH; break; - case ITALK_LENGTH_1: - session->packet_length += c + 1; - session->packet_length *= 2; /* count is in words */ - session->packet_state = ITALK_LENGTH_2; + case ITALK_LENGTH: + session->packet_length += 1; /* fix number of words in payload */ + session->packet_length *= 2; /* convert to number of bytes */ + session->packet_state = ITALK_PAYLOAD; break; - case ITALK_LENGTH_2: - if (--session->packet_length == 0) + case ITALK_PAYLOAD: + /* lookahead for "<!" because sometimes packets are short but valid */ + if ((c == '>') && (session->inbufptr[0] == '<') && (session->inbufptr[1] == '!')) + session->packet_state = ITALK_RECOGNIZED; + else if (--session->packet_length == 0) session->packet_state = ITALK_DELIVERED; break; case ITALK_DELIVERED: if (c == '>') - session->packet_state = ITALK_TRAILER_1; - else - session->packet_state = GROUND_STATE; - break; - case ITALK_TRAILER_1: - if (c == 0xb3) session->packet_state = ITALK_RECOGNIZED; else session->packet_state = GROUND_STATE; break; case ITALK_RECOGNIZED: - if (c == 0xa0) + if (c == '<') session->packet_state = ITALK_LEADER_1; else session->packet_state = GROUND_STATE; @@ -866,9 +863,12 @@ ssize_t packet_parse(struct gps_device_t *session, size_t fix) for (n = sum = 0; n < (unsigned short)(len - 9); n++) sum += getword(9 + n); if (len == 0 || sum == (u_int16_t)getword(len+1)) { + gpsd_report(4, "italk checksum ok\n"); packet_accept(session, ITALK_PACKET); - } else + } else { + gpsd_report(4, "italk checksum failed\n"); session->packet_state = GROUND_STATE; + } packet_discard(session); break; #endif /* ITALK_ENABLE */ diff --git a/packet_states.h b/packet_states.h index 8fad28f0..8f6c174f 100644 --- a/packet_states.h +++ b/packet_states.h @@ -71,11 +71,11 @@ #ifdef ITALK_ENABLE ITALK_LEADER_1, /* saw leading < of iTalk packet */ - ITALK_LEADER_2, /* saw leading * of iTalk packet */ - ITALK_LENGTH_1, /* saw MSB of packet length */ - ITALK_LENGTH_2, /* saw LSB of packet length */ + ITALK_LEADER_2, /* saw leading ! of iTalk packet */ + ITALK_LENGTH, /* saw packet length */ + ITALK_PAYLOAD, /* in payload part of iTalk Packet */ ITALK_DELIVERED, /* seen end of payload */ - ITALK_TRAILER_1, /* saw iTalk trailer byte */ + ITALK_TRAILER, /* saw iTalk trailer byte */ ITALK_RECOGNIZED, /* found end of the iTalk packet */ #endif /* ITALK_ENABLE */ |