From: Mathieu Pilato <redacted>
Date: Sun, 19 Mar 2023 23:10:44 +0000 (+0100)
Subject: fluke-dmm: Update digits count with regard to measurement exponent
X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=104c7d565c67c3e54909fe3cd5d049a66c9961eb;p=libsigrok.git

fluke-dmm: Update digits count with regard to measurement exponent

Also defer the creation of sr_datafeed_analog until the whole message
is parsed, and the number of significant digits is known.
---

diff --git a/src/hardware/fluke-dmm/protocol.c b/src/hardware/fluke-dmm/protocol.c
index ee3c333c..cb641af9 100644
--- a/src/hardware/fluke-dmm/protocol.c
+++ b/src/hardware/fluke-dmm/protocol.c
@@ -56,6 +56,10 @@ static void handle_qm_18x(const struct sr_dev_inst *sdi, char **tokens)
 	char *e, *u;
 	gboolean is_oor;
 	int digits;
+	int exponent;
+	enum sr_mq mq;
+	enum sr_unit unit;
+	enum sr_mqflag mqflags;
 
 	devc = sdi->priv;
 
@@ -86,91 +90,101 @@ static void handle_qm_18x(const struct sr_dev_inst *sdi, char **tokens)
 	while (*e && *e == ' ')
 		e++;
 
-	sr_analog_init(&analog, &encoding, &meaning, &spec, digits);
-	analog.data = &fvalue;
-	analog.meaning->channels = sdi->channels;
-	analog.num_samples = 1;
 	if (is_oor)
 		fvalue = NAN;
-	analog.meaning->mq = 0;
 
+	mq = 0;
+	unit = 0;
+	exponent = 0;
+	mqflags = 0;
 	if ((u = strstr(e, "V DC")) || (u = strstr(e, "V AC"))) {
-		analog.meaning->mq = SR_MQ_VOLTAGE;
-		analog.meaning->unit = SR_UNIT_VOLT;
+		mq = SR_MQ_VOLTAGE;
+		unit = SR_UNIT_VOLT;
 		if (!is_oor && e[0] == 'm')
-			fvalue /= 1000;
+			exponent = -3;
 		/* This catches "V AC", "V DC" and "V AC+DC". */
 		if (strstr(u, "AC"))
-			analog.meaning->mqflags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
+			mqflags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
 		if (strstr(u, "DC"))
-			analog.meaning->mqflags |= SR_MQFLAG_DC;
+			mqflags |= SR_MQFLAG_DC;
 	} else if ((u = strstr(e, "dBV")) || (u = strstr(e, "dBm"))) {
-		analog.meaning->mq = SR_MQ_VOLTAGE;
+		mq = SR_MQ_VOLTAGE;
 		if (u[2] == 'm')
-			analog.meaning->unit = SR_UNIT_DECIBEL_MW;
+			unit = SR_UNIT_DECIBEL_MW;
 		else
-			analog.meaning->unit = SR_UNIT_DECIBEL_VOLT;
-		analog.meaning->mqflags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
+			unit = SR_UNIT_DECIBEL_VOLT;
+		mqflags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
 	} else if ((u = strstr(e, "Ohms"))) {
-		analog.meaning->mq = SR_MQ_RESISTANCE;
-		analog.meaning->unit = SR_UNIT_OHM;
+		mq = SR_MQ_RESISTANCE;
+		unit = SR_UNIT_OHM;
 		if (is_oor)
 			fvalue = INFINITY;
 		else if (e[0] == 'k')
-			fvalue *= 1000;
+			exponent = 3;
 		else if (e[0] == 'M')
-			fvalue *= 1000000;
+			exponent = 6;
 	} else if (!strcmp(e, "nS")) {
-		analog.meaning->mq = SR_MQ_CONDUCTANCE;
-		analog.meaning->unit = SR_UNIT_SIEMENS;
-		*((float *)analog.data) /= 1e+9;
+		mq = SR_MQ_CONDUCTANCE;
+		unit = SR_UNIT_SIEMENS;
+		exponent = -9;
 	} else if ((u = strstr(e, "Farads"))) {
-		analog.meaning->mq = SR_MQ_CAPACITANCE;
-		analog.meaning->unit = SR_UNIT_FARAD;
+		mq = SR_MQ_CAPACITANCE;
+		unit = SR_UNIT_FARAD;
 		if (!is_oor) {
 			if (e[0] == 'm')
-				fvalue /= 1e+3;
+				exponent = -3;
 			else if (e[0] == 'u')
-				fvalue /= 1e+6;
+				exponent = -6;
 			else if (e[0] == 'n')
-				fvalue /= 1e+9;
+				exponent = -9;
 		}
 	} else if ((u = strstr(e, "Deg C")) || (u = strstr(e, "Deg F"))) {
-		analog.meaning->mq = SR_MQ_TEMPERATURE;
+		mq = SR_MQ_TEMPERATURE;
 		if (u[4] == 'C')
-			analog.meaning->unit = SR_UNIT_CELSIUS;
+			unit = SR_UNIT_CELSIUS;
 		else
-			analog.meaning->unit = SR_UNIT_FAHRENHEIT;
+			unit = SR_UNIT_FAHRENHEIT;
 	} else if ((u = strstr(e, "A AC")) || (u = strstr(e, "A DC"))) {
-		analog.meaning->mq = SR_MQ_CURRENT;
-		analog.meaning->unit = SR_UNIT_AMPERE;
+		mq = SR_MQ_CURRENT;
+		unit = SR_UNIT_AMPERE;
 		/* This catches "A AC", "A DC" and "A AC+DC". */
 		if (strstr(u, "AC"))
-			analog.meaning->mqflags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
+			mqflags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
 		if (strstr(u, "DC"))
-			analog.meaning->mqflags |= SR_MQFLAG_DC;
+			mqflags |= SR_MQFLAG_DC;
 		if (!is_oor) {
 			if (e[0] == 'm')
-				fvalue /= 1e+3;
+				exponent = -3;
 			else if (e[0] == 'u')
-				fvalue /= 1e+6;
+				exponent = -6;
 		}
 	} else if ((u = strstr(e, "Hz"))) {
-		analog.meaning->mq = SR_MQ_FREQUENCY;
-		analog.meaning->unit = SR_UNIT_HERTZ;
+		mq = SR_MQ_FREQUENCY;
+		unit = SR_UNIT_HERTZ;
 		if (e[0] == 'k')
-			fvalue *= 1e+3;
+			exponent = 3;
 	} else if (!strcmp(e, "%")) {
-		analog.meaning->mq = SR_MQ_DUTY_CYCLE;
-		analog.meaning->unit = SR_UNIT_PERCENTAGE;
+		mq = SR_MQ_DUTY_CYCLE;
+		unit = SR_UNIT_PERCENTAGE;
 	} else if ((u = strstr(e, "ms"))) {
-		analog.meaning->mq = SR_MQ_PULSE_WIDTH;
-		analog.meaning->unit = SR_UNIT_SECOND;
-		fvalue /= 1e+3;
+		mq = SR_MQ_PULSE_WIDTH;
+		unit = SR_UNIT_SECOND;
+		exponent = -3;
 	}
 
-	if (analog.meaning->mq != 0) {
+	if (mq != 0) {
 		/* Got a measurement. */
+		digits -= exponent;
+		fvalue *= pow(10.0f, exponent);
+
+		sr_analog_init(&analog, &encoding, &meaning, &spec, digits);
+		analog.data = &fvalue;
+		analog.num_samples = 1;
+		analog.meaning->unit = unit;
+		analog.meaning->mq = mq;
+		analog.meaning->mqflags = mqflags;
+		analog.meaning->channels = sdi->channels;
+
 		packet.type = SR_DF_ANALOG;
 		packet.payload = &analog;
 		sr_session_send(sdi, &packet);