From: Uwe Hermann <redacted>
Date: Sat, 1 Dec 2012 23:36:37 +0000 (+0100)
Subject: metex14: Add dB mode and hFE mode support.
X-Git-Tag: dsupstream~502
X-Git-Url: https://sigrok.org/gitweb/?p=libsigrok.git;a=commitdiff_plain;h=9871215c83f70a2008272de03268291445ed59c3

metex14: Add dB mode and hFE mode support.

This is found e.g. on the Metex M-3640D DMM.
---

diff --git a/hardware/common/dmm/metex14.c b/hardware/common/dmm/metex14.c
index 7d1cc056..52a98c85 100644
--- a/hardware/common/dmm/metex14.c
+++ b/hardware/common/dmm/metex14.c
@@ -126,6 +126,13 @@ static void parse_flags(const char *buf, struct metex14_info *info)
 	info->is_temperature = !strncmp(buf, "TE", 2);
 	info->is_diode       = !strncmp(buf, "DI", 2);
 	info->is_frequency   = !strncmp(buf, "FR", 2);
+	info->is_gain        = !strncmp(buf, "DB", 2);
+	info->is_hfe         = !strncmp(buf, "HF", 2);
+
+	/*
+	 * Note: "DB" shows the logarithmic ratio of input voltage to a
+	 * pre-stored (user-changeable) value in the DMM.
+	 */
 
 	if (info->is_dc || info->is_ac)
 		info->is_volt = TRUE;
@@ -159,6 +166,10 @@ static void parse_flags(const char *buf, struct metex14_info *info)
 		info->is_kilo = info->is_hertz = TRUE;
 	else if (!strncmp(buf + 9, "   C", 4))
 		info->is_celsius = TRUE;
+	else if (!strncmp(buf + 9, "  DB", 4))
+		info->is_decibel = TRUE;
+	else if (!strncmp(buf + 9, "    ", 4))
+		info->is_unitless = TRUE;
 
 	/* Byte 13: Always '\r' (carriage return, 0x0d, 13) */
 }
@@ -207,6 +218,14 @@ static void handle_flags(struct sr_datafeed_analog *analog, float *floatval,
 		analog->mq = SR_MQ_VOLTAGE;
 		analog->unit = SR_UNIT_VOLT;
 	}
+	if (info->is_gain) {
+		analog->mq = SR_MQ_GAIN;
+		analog->unit = SR_UNIT_DECIBEL_VOLT;
+	}
+	if (info->is_hfe) {
+		analog->mq = SR_MQ_GAIN;
+		analog->unit = SR_UNIT_UNITLESS;
+	}
 
 	/* Measurement related flags */
 	if (info->is_ac)
diff --git a/libsigrok-internal.h b/libsigrok-internal.h
index bed792b0..0b92a488 100644
--- a/libsigrok-internal.h
+++ b/libsigrok-internal.h
@@ -197,7 +197,7 @@ struct metex14_info {
 	gboolean is_ac, is_dc, is_resistance, is_capacity, is_temperature;
 	gboolean is_diode, is_frequency, is_ampere, is_volt, is_farad;
 	gboolean is_hertz, is_ohm, is_celsius, is_nano, is_micro, is_milli;
-	gboolean is_kilo, is_mega;
+	gboolean is_kilo, is_mega, is_gain, is_decibel, is_hfe, is_unitless;
 };
 
 SR_PRIV int sr_metex14_packet_request(struct sr_serial_dev_inst *serial);