--- /dev/null
+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2014 Uwe Hermann <uwe@hermann-uwe.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * UNI-T UT71x protocol parser.
+ *
+ * Communication parameters: Unidirectional, 2400/7o1
+ */
+
+#include <string.h>
+#include <ctype.h>
+#include <math.h>
+#include <glib.h>
+#include "libsigrok.h"
+#include "libsigrok-internal.h"
+
+#define LOG_PREFIX "ut71x"
+
+/*
+ * Factors for the respective measurement mode (0 means "invalid").
+ *
+ * The Conrad/Voltcraft protocol descriptions have a typo (they suggest
+ * index 0 for the 10A range (which is incorrect, it's range 1).
+ */
+static const float factors[16][8] = {
+ {1e-5, 0, 0, 0, 0, 0, 0, 0 }, /* AC mV */
+ {0, 1e-4, 1e-3, 1e-2, 1e-1, 0, 0, 0 }, /* DC V */
+ {0, 1e-4, 1e-3, 1e-2, 1e-1, 0, 0, 0 }, /* AC V */
+ {1e-5, 0, 0, 0, 0, 0, 0, 0 }, /* DC mV */
+ {0, 1e-1, 1, 1e1, 1e2, 1e3, 1e4, 0 }, /* Resistance */
+ {0, 1e-12, 1e-11, 1e-10, 1e-9, 1e-8, 1e-7, 1e-6}, /* Capacitance */
+ {1e-1, 0, 0, 0, 0, 0, 0, 0 }, /* Temp (C) */
+ {1e-8, 1e-7, 0, 0, 0, 0, 0, 0 }, /* uA */
+ {1e-6, 1e-5, 0, 0, 0, 0, 0, 0 }, /* mA */
+ {0, 1e-3, 0, 0, 0, 0, 0, 0 }, /* 10A */
+ {1e-1, 0, 0, 0, 0, 0, 0, 0 }, /* Continuity */
+ {1e-4, 0, 0, 0, 0, 0, 0, 0 }, /* Diode */
+ {1e-3, 1e-2, 1e-1, 1, 1e1, 1e2, 1e3, 1e4 }, /* Frequency */
+ {1e-1, 0, 0, 0, 0, 0, 0, 0 }, /* Temp (F) */
+ {0, 0, 0, 1, 0, 0, 0, 0 }, /* Power */
+ {1e-2, 0, 0, 0, 0, 0, 0, 0 }, /* Loop current */
+};
+
+static int parse_value(const uint8_t *buf, struct ut71x_info *info, float *result)
+{
+ int i, intval, num_digits = 5;
+
+ /* Bytes 0-4: Value (5 decimal digits) */
+ if (!strncmp((const char *)buf, "::0<:", 5)) {
+ sr_spew("Over limit.");
+ *result = INFINITY;
+ return SR_OK;
+ } else if (!strncmp((const char *)buf, ":<0::", 5)) {
+ sr_spew("Under limit.");
+ *result = INFINITY;
+ return SR_OK;
+ } else if (buf[4] == ':') {
+ sr_dbg("4000 count mode, only 4 digits used.");
+ num_digits = 4;
+ } else if (!isdigit(buf[0]) || !isdigit(buf[1]) ||
+ !isdigit(buf[2]) || !isdigit(buf[3]) || !isdigit(buf[4])) {
+ sr_dbg("Invalid digits: %02x %02x %02x %02x %02x (%c %c "
+ "%c %c %c).", buf[0], buf[1], buf[2], buf[3], buf[4],
+ buf[0], buf[1], buf[2], buf[3], buf[4]);
+ return SR_ERR;
+ }
+ for (i = 0, intval = 0; i < num_digits; i++)
+ intval = 10 * intval + (buf[i] - '0');
+
+ /* Apply sign. */
+ intval *= info->is_sign ? -1 : 1;
+
+ /* Note: The decimal point position will be parsed later. */
+ *result = (float)intval;
+ sr_spew("The display value is %f.", *result);
+
+ return SR_OK;
+}
+
+static int parse_range(const uint8_t *buf, float *floatval)
+{
+ int idx, mode;
+ float factor = 0;
+
+ idx = buf[5] - '0';
+ if (idx < 0 || idx > 7) {
+ sr_dbg("Invalid range byte 0x%02x (idx 0x%02x).", buf[5], idx);
+ return SR_ERR;
+ }
+
+ mode = buf[6] - '0';
+ if (mode < 0 || mode > 15) {
+ sr_dbg("Invalid mode byte 0x%02x (idx 0x%02x).", buf[6], mode);
+ return SR_ERR;
+ }
+
+ sr_spew("mode/idx = %d/%d", mode, idx);
+
+ factor = factors[mode][idx];
+ if (factor == 0) {
+ sr_dbg("Invalid factor for range byte: 0x%02x.", buf[5]);
+ return SR_ERR;
+ }
+
+ /* Apply respective factor (mode-dependent) on the value. */
+ *floatval *= factor;
+ sr_dbg("Applying factor %f, new value is %f.", factor, *floatval);
+
+ return SR_OK;
+}
+
+static void parse_flags(const uint8_t *buf, struct ut71x_info *info)
+{
+ /* Function byte */
+ switch (buf[6] - '0') {
+ case 0: /* AC mV */
+ info->is_voltage = info->is_ac = TRUE;
+ break;
+ case 1: /* DC V */
+ info->is_voltage = info->is_dc = TRUE;
+ break;
+ case 2: /* AC V */
+ info->is_voltage = info->is_ac = TRUE;
+ break;
+ case 3: /* DC mV */
+ info->is_voltage = info->is_dc = TRUE;
+ break;
+ case 4: /* Resistance */
+ info->is_resistance = TRUE;
+ break;
+ case 5: /* Capacitance */
+ info->is_capacitance = TRUE;
+ break;
+ case 6: /* Temperature (Celsius) */
+ info->is_temperature = info->is_celsius = TRUE;
+ break;
+ case 7: /* uA */
+ info->is_current = info->is_dc = TRUE;
+ break;
+ case 8: /* mA */
+ info->is_current = info->is_dc = TRUE;
+ break;
+ case 9: /* 10A */
+ info->is_current = info->is_dc = TRUE;
+ break;
+ case 10: /* Continuity */
+ info->is_continuity = TRUE;
+ break;
+ case 11: /* Diode */
+ info->is_diode = TRUE;
+ break;
+ case 12: /* Frequency */
+ info->is_frequency = TRUE;
+ break;
+ case 13: /* Temperature (F) */
+ info->is_temperature = info->is_fahrenheit = TRUE;
+ break;
+ case 14: /* Power */
+ /* Note: Only available on UT71E (range 0-2500W). */
+ info->is_power = TRUE;
+ break;
+ case 15: /* DC loop current, percentage display (range 4-20mA) */
+ info->is_loop_current = TRUE;
+ break;
+ default:
+ sr_dbg("Invalid function byte: 0x%02x.", buf[6]);
+ break;
+ }
+
+ /*
+ * State 1 byte: bit 0 = AC, bit 1 = DC
+ * Either AC or DC or both or none can be set at the same time.
+ */
+ info->is_ac = (buf[7] & (1 << 0)) != 0;
+ info->is_dc = (buf[7] & (1 << 1)) != 0;
+
+ /*
+ * State 2 byte: bit 0 = auto, bit 1 = manual, bit 2 = sign
+ *
+ * The Conrad/Voltcraft protocol descriptions have a typo
+ * (they suggest bit 3 as sign bit, which is incorrect).
+ *
+ * For modes where there's only one possible range (e.g. AC mV)
+ * neither the "auto" nor the "manual" bits will be set.
+ */
+ info->is_auto = (buf[8] & (1 << 0)) != 0;
+ info->is_manual = (buf[8] & (1 << 1)) != 0;
+ info->is_sign = (buf[8] & (1 << 2)) != 0;
+
+ /* Note: "Frequency mode + sign bit" means "duty cycle mode". */
+ if (info->is_frequency && info->is_sign) {
+ info->is_duty_cycle = TRUE;
+ info->is_frequency = info->is_sign = FALSE;
+ }
+}
+
+static void handle_flags(struct sr_datafeed_analog *analog,
+ float *floatval, const struct ut71x_info *info)
+{
+ /* Measurement modes */
+ if (info->is_voltage) {
+ analog->mq = SR_MQ_VOLTAGE;
+ analog->unit = SR_UNIT_VOLT;
+ }
+ if (info->is_current) {
+ analog->mq = SR_MQ_CURRENT;
+ analog->unit = SR_UNIT_AMPERE;
+ }
+ if (info->is_resistance) {
+ analog->mq = SR_MQ_RESISTANCE;
+ analog->unit = SR_UNIT_OHM;
+ }
+ if (info->is_frequency) {
+ analog->mq = SR_MQ_FREQUENCY;
+ analog->unit = SR_UNIT_HERTZ;
+ }
+ if (info->is_capacitance) {
+ analog->mq = SR_MQ_CAPACITANCE;
+ analog->unit = SR_UNIT_FARAD;
+ }
+ if (info->is_temperature && info->is_celsius) {
+ analog->mq = SR_MQ_TEMPERATURE;
+ analog->unit = SR_UNIT_CELSIUS;
+ }
+ if (info->is_temperature && info->is_fahrenheit) {
+ analog->mq = SR_MQ_TEMPERATURE;
+ analog->unit = SR_UNIT_FAHRENHEIT;
+ }
+ if (info->is_continuity) {
+ analog->mq = SR_MQ_CONTINUITY;
+ analog->unit = SR_UNIT_BOOLEAN;
+ *floatval = (*floatval < 0.0 || *floatval > 60.0) ? 0.0 : 1.0;
+ }
+ if (info->is_diode) {
+ analog->mq = SR_MQ_VOLTAGE;
+ analog->unit = SR_UNIT_VOLT;
+ }
+ if (info->is_duty_cycle) {
+ analog->mq = SR_MQ_DUTY_CYCLE;
+ analog->unit = SR_UNIT_PERCENTAGE;
+ }
+ if (info->is_power) {
+ analog->mq = SR_MQ_POWER;
+ analog->unit = SR_UNIT_WATT;
+ }
+ if (info->is_loop_current) {
+ /* 4mA = 0%, 20mA = 100% */
+ analog->mq = SR_MQ_CURRENT;
+ analog->unit = SR_UNIT_PERCENTAGE;
+ }
+
+ /* Measurement related flags */
+ if (info->is_ac)
+ analog->mqflags |= SR_MQFLAG_AC;
+ if (info->is_dc)
+ analog->mqflags |= SR_MQFLAG_DC;
+ if (info->is_ac)
+ /* All AC modes do True-RMS measurements. */
+ analog->mqflags |= SR_MQFLAG_RMS;
+ if (info->is_auto)
+ analog->mqflags |= SR_MQFLAG_AUTORANGE;
+ if (info->is_diode)
+ analog->mqflags |= SR_MQFLAG_DIODE;
+}
+
+static gboolean flags_valid(const struct ut71x_info *info)
+{
+ int count;
+
+ /* Does the packet "measure" more than one type of value? */
+ count = (info->is_voltage) ? 1 : 0;
+ count += (info->is_current) ? 1 : 0;
+ count += (info->is_resistance) ? 1 : 0;
+ count += (info->is_capacitance) ? 1 : 0;
+ count += (info->is_frequency) ? 1 : 0;
+ count += (info->is_temperature) ? 1 : 0;
+ count += (info->is_continuity) ? 1 : 0;
+ count += (info->is_diode) ? 1 : 0;
+ count += (info->is_power) ? 1 : 0;
+ count += (info->is_loop_current) ? 1 : 0;
+ if (count > 1) {
+ sr_dbg("More than one measurement type detected in packet.");
+ return FALSE;
+ }
+
+ /* Auto and manual can't be active at the same time. */
+ if (info->is_auto && info->is_manual) {
+ sr_dbg("Auto and manual modes are both active.");
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+SR_PRIV gboolean sr_ut71x_packet_valid(const uint8_t *buf)
+{
+ struct ut71x_info info;
+
+ memset(&info, 0, sizeof(struct ut71x_info));
+
+ if (buf[9] != '\r' || buf[10] != '\n')
+ return FALSE;
+
+ parse_flags(buf, &info);
+
+ return flags_valid(&info);
+}
+
+SR_PRIV int sr_ut71x_parse(const uint8_t *buf, float *floatval,
+ struct sr_datafeed_analog *analog, void *info)
+{
+ int ret;
+ struct ut71x_info *info_local;
+
+ info_local = (struct ut71x_info *)info;
+ memset(info_local, 0, sizeof(struct ut71x_info));
+
+ if (!sr_ut71x_packet_valid(buf))
+ return SR_ERR;
+
+ parse_flags(buf, info_local);
+
+ if ((ret = parse_value(buf, info, floatval)) != SR_OK) {
+ sr_dbg("Error parsing value: %d.", ret);
+ return ret;
+ }
+
+ if ((ret = parse_range(buf, floatval)) != SR_OK)
+ return ret;
+
+ handle_flags(analog, floatval, info);
+
+ return SR_OK;
+}
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