Add the sensor index to the ppO2 sample

Rebreathers typically support multiple ppO2 sensors as a safety measure
in case a sensor fails during the dive. The current api can already
report multiple ppO2 values per sample, but it does not provide any
information about which sensor the measurement is from.

The new sensor index provides this info, and can also be used to
distinguish between the average/voted ppO2 value using the special value
DC_SENSOR_NONE.

examples/output_xml.c

@@ -157,7 +157,11 @@ sample_cb (dc_sample_type_t type, dc_sample_value_t value, void *userdata)
 		fprintf (sampledata->ostream, "   <setpoint>%.2f</setpoint>\n", value.setpoint);
 		break;
 	case DC_SAMPLE_PPO2:
-		fprintf (sampledata->ostream, "   <ppo2>%.2f</ppo2>\n", value.ppo2);
+		if (value.ppo2.sensor != DC_SENSOR_NONE) {
+			fprintf (sampledata->ostream, "   <ppo2 sensor=\"%u\">%.2f</ppo2>\n", value.ppo2.sensor, value.ppo2.value);
+		} else {
+			fprintf (sampledata->ostream, "   <ppo2>%.2f</ppo2>\n", value.ppo2.value);
+		}
 		break;
 	case DC_SAMPLE_CNS:
 		fprintf (sampledata->ostream, "   <cns>%.1f</cns>\n", value.cns * 100.0);

include/libdivecomputer/parser.h

@@ -147,6 +147,7 @@ typedef struct dc_gasmix_t {
 	double nitrogen;
 } dc_gasmix_t;
 
+#define DC_SENSOR_NONE    0xFFFFFFFF
 #define DC_GASMIX_UNKNOWN 0xFFFFFFFF
 
 typedef enum dc_tankvolume_t {
@@ -247,7 +248,10 @@ typedef union dc_sample_value_t {
 		const void *data;
 	} vendor;
 	double setpoint;
-	double ppo2;
+	struct {
+		unsigned int sensor;
+		double value;
+	} ppo2;
 	double cns;
 	struct {
 		unsigned int type;

src/diverite_nitekq_parser.c

@@ -293,7 +293,8 @@ diverite_nitekq_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callbac
 				if (offset + 1 > size)
 					return DC_STATUS_DATAFORMAT;
 				unsigned int ppo2 = data[offset];
-				sample.ppo2 = ppo2 / 100.0;
+				sample.ppo2.sensor = DC_SENSOR_NONE;
+				sample.ppo2.value = ppo2 / 100.0;
 				if (callback) callback (DC_SAMPLE_PPO2, sample, userdata);
 				offset++;
 			}

src/divesoft_freedom_parser.c

@@ -946,7 +946,8 @@ divesoft_freedom_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callba
 			if (callback) callback(DC_SAMPLE_DEPTH, sample, userdata);
 
 			if (ppo2) {
-				sample.ppo2 = ppo2 * 10.0 / BAR;
+				sample.ppo2.sensor = DC_SENSOR_NONE;
+				sample.ppo2.value = ppo2 * 10.0 / BAR;
 				if (callback) callback(DC_SAMPLE_PPO2, sample, userdata);
 			}
 
@@ -1045,7 +1046,8 @@ divesoft_freedom_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callba
 					unsigned int ppo2 = array_uint16_le (data + offset + 4 + i * 2);
 					if (ppo2 == 0 || ppo2 == 0xFFFF)
 						continue;
-					sample.ppo2 = ppo2 * 10.0 / BAR;
+					sample.ppo2.sensor = i;
+					sample.ppo2.value = ppo2 * 10.0 / BAR;
 					if (callback) callback(DC_SAMPLE_PPO2, sample, userdata);
 				}
 			} else if (id == MEASURE_ID_OXYGEN_MV) {
@@ -1055,7 +1057,8 @@ divesoft_freedom_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callba
 					if (!parser->calibrated || state == SENSTAT_UNCALIBRATED ||
 						state == SENSTAT_NOT_EXIST)
 						continue;
-					sample.ppo2 = value / 100.0 * parser->calibration[i] / BAR;
+					sample.ppo2.sensor = i;
+					sample.ppo2.value = value / 100.0 * parser->calibration[i] / BAR;
 					if (callback) callback(DC_SAMPLE_PPO2, sample, userdata);
 				}
 			}

src/hw_ostc_parser.c

@@ -1067,7 +1067,8 @@ hw_ostc_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callback_t call
 					}
 					if (count) {
 						for (unsigned int j = 0; j < 3; ++j) {
-							sample.ppo2 = ppo2[j] / 100.0;
+							sample.ppo2.sensor = i;
+							sample.ppo2.value = ppo2[j] / 100.0;
 							if (callback) callback (DC_SAMPLE_PPO2, sample, userdata);
 						}
 					}

src/shearwater_predator_parser.c

@@ -927,19 +927,21 @@ shearwater_predator_parser_samples_foreach (dc_parser_t *abstract, dc_sample_cal
 			if (ccr) {
 				// PPO2
 				if ((status & PPO2_EXTERNAL) == 0) {
-#ifdef SENSOR_AVERAGE
+					sample.ppo2.sensor = DC_SENSOR_NONE;
-					sample.ppo2 = data[offset + pnf + 6] / 100.0;
+					sample.ppo2.value = data[offset + pnf + 6] / 100.0;
 					if (callback) callback (DC_SAMPLE_PPO2, sample, userdata);
-#else
+
-					sample.ppo2 = data[offset + pnf + 12] * parser->calibration[0];
+					sample.ppo2.sensor = 0;
+					sample.ppo2.value = data[offset + pnf + 12] * parser->calibration[0];
 					if (callback && (parser->calibrated & 0x01)) callback (DC_SAMPLE_PPO2, sample, userdata);
 
-					sample.ppo2 = data[offset + pnf + 14] * parser->calibration[1];
+					sample.ppo2.sensor = 1;
+					sample.ppo2.value = data[offset + pnf + 14] * parser->calibration[1];
 					if (callback && (parser->calibrated & 0x02)) callback (DC_SAMPLE_PPO2, sample, userdata);
 
-					sample.ppo2 = data[offset + pnf + 15] * parser->calibration[2];
+					sample.ppo2.sensor = 2;
+					sample.ppo2.value = data[offset + pnf + 15] * parser->calibration[2];
 					if (callback && (parser->calibrated & 0x04)) callback (DC_SAMPLE_PPO2, sample, userdata);
-#endif
 				}
 
 				// Setpoint

src/tecdiving_divecomputereu_parser.c

@@ -174,7 +174,8 @@ tecdiving_divecomputereu_parser_samples_foreach (dc_parser_t *abstract, dc_sampl
 
 		// ppO2
 		unsigned int ppo2 = data[offset + 1];
-		sample.ppo2 = ppo2 / 10.0;
+		sample.ppo2.sensor = DC_SENSOR_NONE;
+		sample.ppo2.value = ppo2 / 10.0;
 		if (callback) callback (DC_SAMPLE_PPO2, sample, userdata);
 
 		// Setpoint