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suunto_nautic: handshake wait on reconnect, trimix, end pressure, /Summary values #10

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Merged
latishab merged 3 commits into from
Oct 11, 2026
Merged

suunto_nautic: handshake wait on reconnect, trimix, end pressure, /Summary values #10

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adf7eab
suunto_nautic: wait for the EVA handshake reply before returning from…
latishab Oct 11, 2026
e70b6e3
suunto_nautic: read He as int16, and water type, average depth and te…
latishab Oct 11, 2026
457b5f0
suunto_nautic: end pressure as the watch records it at the end of the…
latishab Oct 11, 2026
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42 changes: 32 additions & 10 deletions src/suunto_nautic.c
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Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,7 @@
#define RPC_OP_DATA 0x05
#define RPC_OP_STREAM_START 0x08 // watch -> host: stream accepted (200) or refused (e.g. 423 Locked)
#define RPC_OP_STREAM_END 0x09 // watch -> host: the stream is closed (answers STREAM_STOP)
#define RPC_OP_HELLO_ACK 0x13 // watch -> host: answers the EVA (Hello, 0x12) handshake

// The /Data "stream" is a Whiteboard subscription: 0x10 subscribes to a
// resource handle (answered by 0x08 with the current value), the watch then
Expand Down Expand Up @@ -469,8 +470,8 @@ suunto_nautic_device_open (dc_device_t **out, dc_context_t *context, dc_iostream

dc_iostream_purge (device->iostream, DC_DIRECTION_ALL);

// Best-effort EVA handshake. The response content can't be validated
// (its format isn't understood), so only the I/O round-trip is required.
// EVA handshake. The response content can't be validated (its format isn't
// understood), but its arrival can: the watch answers with a Hello-Ack.
HEXDUMP (context, DC_LOGLEVEL_DEBUG, "EVA REQ", suunto_nautic_eva_handshake, EVA_HANDSHAKE_SIZE);

status = dc_iostream_write (device->iostream, suunto_nautic_eva_handshake, EVA_HANDSHAKE_SIZE, NULL);
Expand All @@ -479,17 +480,38 @@ suunto_nautic_device_open (dc_device_t **out, dc_context_t *context, dc_iostream
goto error_close;
}

// On a quick reconnect the watch is still sending the tail of the stream the
// dropped link was reading, ahead of the Hello-Ack, and a request sent before
// the Ack has arrived can go unanswered. The purge above runs too early to
// catch those frames, so skip them here until the Ack turns up. If the link
// goes quiet without one, carry on as before: the stale frames are drained.
unsigned char handshake_rsp[MAX_PACKET] = {0};
size_t handshake_len = 0;
status = dc_iostream_read (device->iostream, handshake_rsp, sizeof (handshake_rsp), &handshake_len);
if (status != DC_STATUS_SUCCESS) {
ERROR (context, "Failed to receive the EVA handshake response. The device may not "
"support this protocol, or the handshake payload may need updating "
"(see suunto_nautic.h).");
goto error_close;
}
unsigned int handshake_skips = 0;
for (;;) {
status = dc_iostream_read (device->iostream, handshake_rsp, sizeof (handshake_rsp), &handshake_len);
if (status == DC_STATUS_TIMEOUT && handshake_skips > 0) {
WARNING (context, "No EVA handshake response after %u other frames; continuing.", handshake_skips);
break;
}
if (status != DC_STATUS_SUCCESS) {
ERROR (context, "Failed to receive the EVA handshake response. The device may not "
"support this protocol, or the handshake payload may need updating "
"(see suunto_nautic.h).");
goto error_close;
}

HEXDUMP (context, DC_LOGLEVEL_DEBUG, "EVA RSP", handshake_rsp, handshake_len);

HEXDUMP (context, DC_LOGLEVEL_DEBUG, "EVA RSP", handshake_rsp, handshake_len);
if (handshake_len >= 2 && handshake_rsp[0] == 0xA5 && handshake_rsp[1] == RPC_OP_HELLO_ACK)
break;
if (++handshake_skips >= MAX_FOREIGN_SKIPS) {
ERROR (context, "No EVA handshake response among the frames on the link.");
status = DC_STATUS_TIMEOUT;
goto error_close;
}
WARNING (context, "Skipping a frame ahead of the EVA handshake response (" DC_PRINTF_SIZE " bytes).", handshake_len);
}

*out = (dc_device_t *) device;

Expand Down
129 changes: 113 additions & 16 deletions src/suunto_nautic_parser.c
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Original file line number Diff line number Diff line change
Expand Up @@ -128,29 +128,45 @@
// gives low > high.
#define SUMMARY_GF_LOW 0x35 // uint16 LE, %
#define SUMMARY_GF_HIGH 0x33 // uint16 LE, %
// Water type (uint8): 0 fresh, 1 EN13319, 2 salt.
#define SUMMARY_WATER_TYPE 0x3E
// Gas/cylinder records: an array starting at SUMMARY_GAS_BASE, one 45-byte
// record per configured gas. The record index equals the cylinder slot /
// GasNumber, so tank i uses gas i. Within a record: O2% at +1, He% at +2,
// PO2-max (float32 LE, bar) at +5, cylinder water capacity (float32 LE, m^3)
// at +9. Confirmed on two real dual-gas dives (Air 12 L + NX26 5.7 L, two
// GasNumber, so tank i uses gas i. Within a record: O2% (int16 LE) at +1,
// He% (int16 LE) at +3, PO2-max (float32 LE, bar) at +5, cylinder water
// capacity (float32 LE, m^3) at +9, as the watch's own /Summary schema lays
// them out. Confirmed on two real dual-gas dives (Air 12 L + NX26 5.7 L, two
// transmitters -- issue #29/#33/#34); a lone gas dive stops at the first
// implausible slot, as before.
#define SUMMARY_GAS_BASE 0xC7
#define SUMMARY_GAS_STRIDE 45
#define SUMMARY_GAS_O2 1 // uint8, %
#define SUMMARY_GAS_HE 2 // uint8, %
#define SUMMARY_GAS_O2 1 // int16 LE, %
#define SUMMARY_GAS_HE 3 // int16 LE, %
#define SUMMARY_GAS_VOLUME 9 // float32 LE, m^3
// The dive record, the last /Summary record long enough to hold these, carries
// the watch's own dive time and maximum depth (the app's DiveTime and
// Depth.Max), at the same payload offsets on 2040, 2056 and 2342 B summaries.
// Depth.Max), at the same payload offsets on 2040, 2056 and 2342 B summaries,
// along with the app's DepthAverage (diving only) and Temperature.Min/Max.
#define SUMMARY_DIVE_TEMP_MIN 313 // float32 LE, K
#define SUMMARY_DIVE_TEMP_MAX 317 // float32 LE, K
#define SUMMARY_DIVE_DIVETIME 321 // float32 LE, s, fractional
#define SUMMARY_DIVE_MAXDEPTH 330 // float32 LE, m
#define SUMMARY_DIVE_AVGDEPTH 338 // float32 LE, m
// The DiveFooter (the second record) repeats the gas records from +282, with
// each transmitter's start/end pressure: tank 1 at +25/+29, tank 2 at +33/+37
// (int32 LE, Pa). The end pressures are the app's; the start pressures keep a
// transmitter's pre-pairing dropout value (9 bar on 1788683271), so they aren't used.
#define SUMMARY_FOOTER_RECORD 1
#define SUMMARY_FOOTER_GAS_BASE 282
#define SUMMARY_FOOTER_GAS_END1 29
#define SUMMARY_FOOTER_GAS_END2 37

typedef struct suunto_nautic_tank_t {
unsigned int used;
double beginpressure; // bar
double endpressure; // bar
unsigned int gasmix; // gas index (== cylinder slot / GasNumber)
unsigned int field; // 0 = Pressure (first transmitter), 1 = Pressure2
} suunto_nautic_tank_t;

typedef struct suunto_nautic_parser_t {
Expand Down Expand Up @@ -178,6 +194,8 @@ typedef struct suunto_nautic_parser_t {
double gasvolume[MAX_GASMIXES]; // cylinder water capacity, litres (0 = unknown)
unsigned int have_decomodel;
dc_decomodel_t decomodel;
unsigned int have_salinity;
dc_salinity_t salinity;
} suunto_nautic_parser_t;

typedef struct sbem_chunk_t {
Expand Down Expand Up @@ -306,9 +324,34 @@ suunto_nautic_find_summary (const unsigned char *data, size_t size)
return size;
}

// The /Summary's dive record: its records are plain [id][len] TLVs (the
// profile's fixed-length table doesn't apply), ending in trailing bytes that
// don't form a whole record.
// The /Summary's records are plain [id][len] TLVs (the profile's fixed-length
// table doesn't apply), ending in trailing bytes that don't form a whole
// record. Record ids differ between models, so records are found by position.
static const unsigned char *
suunto_nautic_summary_record (const unsigned char *sbem, size_t size, unsigned int index, size_t *out_length)
{
size_t pos = SBEM_MAGIC_SIZE;
for (unsigned int i = 0; pos + 2 <= size; i++) {
size_t length = sbem[pos + 1];
size_t header = 2;
if (length == 255) {
if (pos + 6 > size)
break;
length = array_uint32_le (sbem + pos + 2);
header = 6;
}
if (length > size - pos - header)
break;
if (i == index) {
*out_length = length;
return sbem + pos + header;
}
pos += header + length;
}
return NULL;
}

// The /Summary's dive record: the last record long enough to hold its fields.
static const unsigned char *
suunto_nautic_summary_dive_record (const unsigned char *sbem, size_t size)
{
Expand All @@ -325,7 +368,7 @@ suunto_nautic_summary_dive_record (const unsigned char *sbem, size_t size)
}
if (length > size - pos - header)
break;
if (length >= SUMMARY_DIVE_MAXDEPTH + 4)
if (length >= SUMMARY_DIVE_AVGDEPTH + 4)
record = sbem + pos + header;
pos += header + length;
}
Expand All @@ -350,13 +393,23 @@ suunto_nautic_parse_summary (suunto_nautic_parser_t *parser, const unsigned char
parser->have_decomodel = 1;
}

if (size > SUMMARY_WATER_TYPE) {
unsigned int type = sbem[SUMMARY_WATER_TYPE];
if (type <= 2) {
static const double density[] = {1000.0, 1020.0, 1030.0};
parser->salinity.type = type ? DC_WATER_SALT : DC_WATER_FRESH;
parser->salinity.density = density[type];
parser->have_salinity = 1;
}
}

for (unsigned int i = 0; i < MAX_GASMIXES; i++) {
size_t base = SUMMARY_GAS_BASE + (size_t) i * SUMMARY_GAS_STRIDE;
if (base + SUMMARY_GAS_O2 >= size)
if (base + SUMMARY_GAS_HE + 2 > size)
break;
unsigned int o2 = sbem[base + SUMMARY_GAS_O2];
unsigned int he = sbem[base + SUMMARY_GAS_HE];
if (o2 < 1 || o2 > 100 || he > 100 || o2 + he > 100)
int o2 = (int16_t) array_uint16_le (sbem + base + SUMMARY_GAS_O2);
int he = (int16_t) array_uint16_le (sbem + base + SUMMARY_GAS_HE);
if (o2 < 1 || o2 > 100 || he < 0 || he > 100 || o2 + he > 100)
break; // unused/implausible slot -- stop
unsigned int g = parser->ngasmixes;
parser->gasmix[g].oxygen = o2 / 100.0;
Expand Down Expand Up @@ -486,10 +539,15 @@ suunto_nautic_parser_parse (dc_parser_t *abstract, dc_sample_callback_t callback
// it has read non-zero at least twice (p2_first holds the first value).
int tankmap[MAX_TANKS * 2];
int p2_first[MAX_TANKS];
// The last reading of each tank while Diving: readings taken on the surface
// after the dive can be of a closed, purged regulator (~1 bar).
double diving_end[MAX_TANKS];
for (unsigned int ti = 0; ti < MAX_TANKS * 2; ti++)
tankmap[ti] = -1;
for (unsigned int ti = 0; ti < MAX_TANKS; ti++)
for (unsigned int ti = 0; ti < MAX_TANKS; ti++) {
p2_first[ti] = -1;
diving_end[ti] = -1.0;
}

unsigned int have_location = 0;
dc_location_t location = {0};
Expand Down Expand Up @@ -621,6 +679,7 @@ suunto_nautic_parser_parse (dc_parser_t *abstract, dc_sample_callback_t callback
// Cylinder slot index == GasNumber, so this tank
// breathes gas i (linked to gasmix[i] below).
tank[ntanks].gasmix = i;
tank[ntanks].field = field;
// Seed begin from the first observed reading (the deferred
// one for Pressure2); refined to the max below.
tank[ntanks].beginpressure = (field == 1 && p2_first[i] >= 0)
Expand All @@ -629,6 +688,8 @@ suunto_nautic_parser_parse (dc_parser_t *abstract, dc_sample_callback_t callback
}
unsigned int t = (unsigned int) tankmap[key];
tank[t].endpressure = bar;
if (dive_state == DIVE_STATE_DIVING)
diving_end[t] = bar;
// Begin pressure = the highest reading seen: a cylinder only
// loses pressure during a dive, so the max is the true start.
// This ignores an initial dropout where a transmitter that
Expand Down Expand Up @@ -888,6 +949,10 @@ suunto_nautic_parser_parse (dc_parser_t *abstract, dc_sample_callback_t callback
parser->temperature_surface = temperature_surface;
parser->temperature_minimum = temperature_minimum;
parser->temperature_maximum = temperature_maximum;
for (unsigned int t = 0; t < ntanks; t++) {
if (diving_end[t] >= 0.0)
tank[t].endpressure = diving_end[t];
}
parser->ntanks = ntanks;
memcpy (parser->tank, tank, sizeof (tank));
parser->have_location = have_location;
Expand All @@ -900,6 +965,8 @@ suunto_nautic_parser_parse (dc_parser_t *abstract, dc_sample_callback_t callback
// Gradient factors and gas mixes from the appended /Summary section.
parser->ngasmixes = 0;
parser->have_decomodel = 0;
parser->have_salinity = 0;
memset (&parser->salinity, 0, sizeof (parser->salinity));
memset (parser->gasmix, 0, sizeof (parser->gasmix));
memset (parser->gasvolume, 0, sizeof (parser->gasvolume));
memset (&parser->decomodel, 0, sizeof (parser->decomodel));
Expand All @@ -910,7 +977,10 @@ suunto_nautic_parser_parse (dc_parser_t *abstract, dc_sample_callback_t callback

// The watch's maximum is deeper than any logged sample (the app shows
// it). Trusted only on a record whose dive time agrees with the
// profile's, and when it is close to the sampled maximum.
// profile's, and when it is close to the sampled maximum. The same
// record's average depth and water temperature range are the app's
// figures too; the temperatures are taken only as a sane pair, since
// one Ocean dive records its minimum above its maximum.
const unsigned char *record = suunto_nautic_summary_dive_record (sbem, sbem_size);
if (record && parser->divetime > 0) {
double divetime = array_float_le (record + SUMMARY_DIVE_DIVETIME);
Expand All @@ -921,6 +991,28 @@ suunto_nautic_parser_parse (dc_parser_t *abstract, dc_sample_callback_t callback
parser->divetime = (unsigned int) divetime;
if (maxdepth > 0.0 && depth >= maxdepth - 0.5 && depth <= maxdepth + 3.0)
parser->maxdepth = depth;
double avgdepth = array_float_le (record + SUMMARY_DIVE_AVGDEPTH);
if (avgdepth > 0.0 && avgdepth <= parser->maxdepth)
parser->avgdepth = avgdepth;
double tmin = array_float_le (record + SUMMARY_DIVE_TEMP_MIN);
double tmax = array_float_le (record + SUMMARY_DIVE_TEMP_MAX);
if (have_temperature && tmin > 250.0 && tmax < 330.0 && tmin <= tmax) {
parser->temperature_minimum = tmin - 273.15;
parser->temperature_maximum = tmax - 273.15;
}

size_t footer_size = 0;
const unsigned char *footer = suunto_nautic_summary_record (sbem, sbem_size, SUMMARY_FOOTER_RECORD, &footer_size);
for (unsigned int t = 0; footer && t < parser->ntanks; t++) {
suunto_nautic_tank_t *tk = &parser->tank[t];
size_t base = SUMMARY_FOOTER_GAS_BASE + (size_t) tk->gasmix * SUMMARY_GAS_STRIDE;
if (base + SUMMARY_GAS_STRIDE > footer_size)
continue;
int pa = (int) array_uint32_le (footer + base + (tk->field ? SUMMARY_FOOTER_GAS_END2 : SUMMARY_FOOTER_GAS_END1));
double bar = pa / 100000.0;
if (bar > 0.0 && bar <= tk->beginpressure + 1.0)
tk->endpressure = bar;
}
}
}
}
Expand Down Expand Up @@ -1047,6 +1139,11 @@ suunto_nautic_parser_get_field (dc_parser_t *abstract, dc_field_type_t type, uns
case DC_FIELD_DIVEMODE:
*((dc_divemode_t *) value) = parser->divemode;
break;
case DC_FIELD_SALINITY:
if (!parser->have_salinity)
return DC_STATUS_UNSUPPORTED;
*((dc_salinity_t *) value) = parser->salinity;
break;
default:
return DC_STATUS_UNSUPPORTED;
}
Expand Down
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