[libsigrok.git] / src / dmm / vc870.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2014-2015 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, see <http://www.gnu.org/licenses/>.
 */

#include <config.h>
#include <string.h>
#include <ctype.h>
#include <math.h>
#include <glib.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"

#define LOG_PREFIX "vc870"

/* Exponents for the respective measurement mode. */
static const int exponents[][8] = {
	{  -4,  -3,  -2, -1,  0,  0,  0,  0 }, /* DCV */
	{  -3,  -2,  -1,  0,  0,  0,  0,  0 }, /* ACV */
	{  -5,   0,   0,  0,  0,  0,  0,  0 }, /* DCmV */
	{  -1,   0,   0,  0,  0,  0,  0,  0 }, /* Temperature (C) */
//	{  -2,   0,   0,  0,  0,  0,  0,  0 }, /* TODO: Temperature (F) */
	/*
	 * Note: The sequence -1 -> 1 for the resistance
	 * value is correct and verified in practice!
	 * Don't trust the vendor docs on this.
	 */
	{  -2,  -1,   1,  2,  3,  4,  0,  0 }, /* Resistance */
	{  -2,   0,   0,  0,  0,  0,  0,  0 }, /* Continuity */
	{ -12, -11, -10, -9, -8, -7, -6,  0 }, /* Capacitance */
	{  -4,   0,   0,  0,  0,  0,  0,  0 }, /* Diode */
	{  -3,  -2,  -1,  0,  1,  2,  3,  4 }, /* Frequency */
	{  -2,   0,   0,  0,  0,  0,  0,  0 }, /* Loop current */
	/*
	 * Note: Measurements showed that AC and DC differ
	 * in the exponents used, although docs say they should
	 * be the same.
	 */
	{  -8,  -7,   0,  0,  0,  0,  0,  0 }, /* DCµA */
	{  -7,  -6,   0,  0,  0,  0,  0,  0 }, /* ACµA */
	{  -6,  -5,   0,  0,  0,  0,  0,  0 }, /* DCmA */
	{  -5,  -4,   0,  0,  0,  0,  0,  0 }, /* ACmA */
	{  -3,   0,   0,  0,  0,  0,  0,  0 }, /* DCA */
	/* TODO: Verify exponent for ACA */
	{  -3,   0,   0,  0,  0,  0,  0,  0 }, /* ACA */
	{  -1,   0,   0,  0,  0,  0,  0,  0 }, /* Act+apparent power */
	{  -3,   0,   0,  0,  0,  0,  0,  0 }, /* Power exponent / freq */
	{  -1,   0,   0,  0,  0,  0,  0,  0 }, /* V eff + A eff */
};

static int parse_value(const uint8_t *buf, struct vc870_info *info,
                       float *result)
{
	int i, intval;

	/* Bytes 3-7: Main display value (5 decimal digits) */
	if (info->is_open || info->is_ol1) {
		sr_spew("Over limit.");
		*result = INFINITY;
		return SR_OK;
	} else if (!isdigit(buf[3]) || !isdigit(buf[4]) ||
	           !isdigit(buf[5]) || !isdigit(buf[6]) || !isdigit(buf[7])) {
		sr_dbg("Invalid digits: %02x %02x %02x %02x %02X "
			"(%c %c %c %c %c).",
			buf[3], buf[4], buf[5], buf[6], buf[7],
			buf[3], buf[4], buf[5], buf[6], buf[7]);
		return SR_ERR;
	}

	intval = 0;
	for (i = 0; i < 5; i++)
		intval = 10 * intval + (buf[i + 3] - '0'); /* Main display. */
		// intval = 10 * intval + (buf[i + 8] - '0'); /* TODO: Aux display. */

	/* Apply sign. */
	intval *= info->is_sign1 ? -1 : 1;
	// intval *= info->is_sign2 ? -1 : 1; /* TODO: Fahrenheit / aux display. */

	/* Note: The decimal point position will be parsed later. */

	sr_spew("The display value without comma is %05d.", intval);

	*result = (float)intval;

	return SR_OK;
}

static int parse_range(uint8_t b, float *floatval, int *exponent,
                       const struct vc870_info *info)
{
	int idx, mode;

	idx = b - '0';

	if (idx < 0 || idx > 7) {
		sr_dbg("Invalid range byte / index: 0x%02x / 0x%02x.", b, idx);
		return SR_ERR;
	}

	/* Parse range byte (depends on the measurement mode). */
	if (info->is_voltage && info->is_dc && !info->is_milli)
		mode = 0; /* DCV */
	else if (info->is_voltage && info->is_ac)
		mode = 1; /* ACV */
	else if (info->is_voltage && info->is_dc && info->is_milli)
		mode = 2; /* DCmV */
	else if (info->is_temperature)
		mode = 3; /* Temperature */
	else if (info->is_resistance || info->is_continuity)
		mode = 4; /* Resistance */
	else if (info->is_continuity)
		mode = 5; /* Continuity */
	else if (info->is_capacitance)
		mode = 6; /* Capacitance */
	else if (info->is_diode)
		mode = 7; /* Diode */
	else if (info->is_frequency)
		mode = 8; /* Frequency */
	else if (info->is_loop_current)
		mode = 9; /* Loop current */
	else if (info->is_current && info->is_micro && info->is_dc)
		mode = 10; /* DCµA */
	else if (info->is_current && info->is_micro && info->is_ac)
		mode = 11; /* ACµA */
	else if (info->is_current && info->is_milli && info->is_dc)
		mode = 12; /* DCmA */
	else if (info->is_current && info->is_milli && info->is_ac)
		mode = 13; /* ACmA */
	else if (info->is_current && !info->is_milli && !info->is_micro && info->is_dc)
		mode = 14; /* DCA */
	else if (info->is_current && !info->is_milli && !info->is_micro && info->is_ac)
		mode = 15; /* ACA */
	else if (info->is_power_apparent_power)
		mode = 16; /* Act+apparent power */
	else if (info->is_power_factor_freq)
		mode = 17; /* Power factor / freq */
	else if (info->is_v_a_rms_value)
		mode = 18; /* V eff + A eff */
	else {
		sr_dbg("Invalid mode, range byte was: 0x%02x.", b);
		return SR_ERR;
	}

	*exponent = exponents[mode][idx];

	/* Apply respective exponent (mode-dependent) on the value. */
	*floatval *= powf(10, *exponent);
	sr_dbg("Applying exponent %d, new value is %f.", *exponent, *floatval);

	return SR_OK;
}

static void parse_flags(const uint8_t *buf, struct vc870_info *info)
{
	/* Bytes 0/1: Function / function select */
	/* Note: Some of these mappings are fixed up later. */
	switch (buf[0]) {
	case 0x30: /* DCV / ACV */
		info->is_voltage = TRUE;
		info->is_dc = (buf[1] == 0x30);
		info->is_ac = (buf[1] == 0x31);
		break;
	case 0x31: /* DCmV / Celsius */
		if (buf[1] == 0x30)
			info->is_voltage = info->is_milli = info->is_dc = TRUE;
		else if (buf[1] == 0x31)
			info->is_temperature = TRUE;
		break;
	case 0x32: /* Resistance / Short-circuit test */
		info->is_resistance = (buf[1] == 0x30);
		info->is_continuity = (buf[1] == 0x31);
		break;
	case 0x33: /* Capacitance */
		info->is_capacitance = (buf[1] == 0x30);
		break;
	case 0x34: /* Diode */
		info->is_diode = (buf[1] == 0x30);
		break;
	case 0x35: /* (4~20mA)% */
		info->is_frequency = (buf[1] == 0x30);
		info->is_loop_current = (buf[1] == 0x31);
		break;
	case 0x36: /* DCµA / ACµA */
		info->is_current = info->is_micro = TRUE;
		info->is_dc = (buf[1] == 0x30);
		info->is_ac = (buf[1] == 0x31);
		break;
	case 0x37: /* DCmA / ACmA */
		info->is_current = info->is_milli = TRUE;
		info->is_dc = (buf[1] == 0x30);
		info->is_ac = (buf[1] == 0x31);
		break;
	case 0x38: /* DCA / ACA */
		info->is_current = TRUE;
		info->is_dc = (buf[1] == 0x30);
		info->is_ac = (buf[1] == 0x31);
		break;
	case 0x39: /* Active power + apparent power / power factor + frequency */
		if (buf[1] == 0x30)
			/* Active power + apparent power */
			info->is_power_apparent_power = TRUE;
		else if (buf[1] == 0x31)
			/* Power factor + frequency */
			info->is_power_factor_freq = TRUE;
		else if (buf[1] == 0x32)
			/* Voltage effective value + current effective value */
			info->is_v_a_rms_value = TRUE;
		break;
	default:
		sr_dbg("Invalid function bytes: %02x %02x.", buf[0], buf[1]);
		break;
	}

	/* Byte 2: Range */

	/* Byte 3-7: Main display digits */

	/* Byte 8-12: Auxiliary display digits */

	/* Byte 13: TODO: "Simulate strip tens digit". */

	/* Byte 14: TODO: "Simulate strip the single digit". */

	/* Byte 15: Status */
	info->is_sign2        = (buf[15] & (1 << 3)) != 0;
	info->is_sign1        = (buf[15] & (1 << 2)) != 0;
	info->is_batt         = (buf[15] & (1 << 1)) != 0; /* Bat. low */
	info->is_ol1          = (buf[15] & (1 << 0)) != 0; /* Overflow (main display) */

	/* Byte 16: Option 1 */
	info->is_max          = (buf[16] & (1 << 3)) != 0;
	info->is_min          = (buf[16] & (1 << 2)) != 0;
	info->is_maxmin       = (buf[16] & (1 << 1)) != 0;
	info->is_rel          = (buf[16] & (1 << 0)) != 0;

	/* Byte 17: Option 2 */
	info->is_ol2          = (buf[17] & (1 << 3)) != 0;
	info->is_open         = (buf[17] & (1 << 2)) != 0;
	info->is_manu         = (buf[17] & (1 << 1)) != 0; /* Manual mode */
	info->is_hold         = (buf[17] & (1 << 0)) != 0; /* Hold */

	/* Byte 18: Option 3 */
	info->is_light        = (buf[18] & (1 << 3)) != 0;
	info->is_usb          = (buf[18] & (1 << 2)) != 0; /* Always on */
	info->is_warning      = (buf[18] & (1 << 1)) != 0; /* Never seen? */
	info->is_auto_power   = (buf[18] & (1 << 0)) != 0; /* Always on */

	/* Byte 19: Option 4 */
	info->is_misplug_warn = (buf[19] & (1 << 3)) != 0; /* Never gets set? */
	info->is_lo           = (buf[19] & (1 << 2)) != 0;
	info->is_hi           = (buf[19] & (1 << 1)) != 0;
	info->is_open2        = (buf[19] & (1 << 0)) != 0; /* TODO: Unknown. */

	/* Byte 20: Dual display bit */
	info->is_dual_display = (buf[20] & (1 << 0)) != 0;

	/* Byte 21: Always '\r' (carriage return, 0x0d, 13) */

	/* Byte 22: Always '\n' (newline, 0x0a, 10) */

	info->is_auto = !info->is_manu;
}

static void handle_flags(struct sr_datafeed_analog *analog,
			 float *floatval, const struct vc870_info *info)
{
	/*
	 * Note: is_micro etc. are not used directly to multiply/divide
	 * floatval, this is handled via parse_range() and exponents[][].
	 */

	/* Measurement modes */
	if (info->is_voltage) {
		analog->meaning->mq = SR_MQ_VOLTAGE;
		analog->meaning->unit = SR_UNIT_VOLT;
	}
	if (info->is_current) {
		analog->meaning->mq = SR_MQ_CURRENT;
		analog->meaning->unit = SR_UNIT_AMPERE;
	}
	if (info->is_resistance) {
		analog->meaning->mq = SR_MQ_RESISTANCE;
		analog->meaning->unit = SR_UNIT_OHM;
	}
	if (info->is_frequency) {
		analog->meaning->mq = SR_MQ_FREQUENCY;
		analog->meaning->unit = SR_UNIT_HERTZ;
	}
	if (info->is_capacitance) {
		analog->meaning->mq = SR_MQ_CAPACITANCE;
		analog->meaning->unit = SR_UNIT_FARAD;
	}
	if (info->is_temperature) {
		analog->meaning->mq = SR_MQ_TEMPERATURE;
		analog->meaning->unit = SR_UNIT_CELSIUS;
		/* TODO: Handle Fahrenheit in auxiliary display. */
		// analog->meaning->unit = SR_UNIT_FAHRENHEIT;
	}
	if (info->is_continuity) {
		analog->meaning->mq = SR_MQ_CONTINUITY;
		analog->meaning->unit = SR_UNIT_BOOLEAN;
		/* Vendor docs: "< 20 Ohm acoustic" */
		*floatval = (*floatval < 0.0 || *floatval > 20.0) ? 0.0 : 1.0;
	}
	if (info->is_diode) {
		analog->meaning->mq = SR_MQ_VOLTAGE;
		analog->meaning->unit = SR_UNIT_VOLT;
	}
	if (info->is_loop_current) {
		/* 4mA = 0%, 20mA = 100% */
		analog->meaning->mq = SR_MQ_CURRENT;
		analog->meaning->unit = SR_UNIT_PERCENTAGE;
	}
	if (info->is_power) {
		analog->meaning->mq = SR_MQ_POWER;
		analog->meaning->unit = SR_UNIT_WATT;
	}
	if (info->is_power_apparent_power) {
		analog->meaning->mq = SR_MQ_POWER;
		analog->meaning->unit = SR_UNIT_WATT;
		/* TODO: Handle apparent power. */
		// analog->meaning->mq = SR_MQ_APPARENT_POWER;
		// analog->meaning->unit = SR_UNIT_VOLT_AMPERE;
	}
	if (info->is_power_factor_freq) {
		analog->meaning->mq = SR_MQ_POWER_FACTOR;
		analog->meaning->unit = SR_UNIT_UNITLESS;
		/* TODO: Handle frequency. */
		// analog->meaning->mq = SR_MQ_FREQUENCY;
		// analog->meaning->unit = SR_UNIT_HERTZ;
	}
	if (info->is_v_a_rms_value) {
		analog->meaning->mqflags |= SR_MQFLAG_RMS;
		analog->meaning->mq = SR_MQ_VOLTAGE;
		analog->meaning->unit = SR_UNIT_VOLT;
		/* TODO: Handle effective current value */
		// analog->meaning->mq = SR_MQ_CURRENT;
		// analog->meaning->unit = SR_UNIT_AMPERE;
	}

	/* Measurement related flags */
	if (info->is_ac)
		analog->meaning->mqflags |= SR_MQFLAG_AC;
	if (info->is_dc)
		analog->meaning->mqflags |= SR_MQFLAG_DC;
	if (info->is_auto)
		analog->meaning->mqflags |= SR_MQFLAG_AUTORANGE;
	if (info->is_diode)
		analog->meaning->mqflags |= SR_MQFLAG_DIODE | SR_MQFLAG_DC;
	if (info->is_hold)
		/*
		 * Note: HOLD only affects the number displayed on the LCD,
		 * but not the value sent via the protocol! It also does not
		 * affect the bargraph on the LCD.
		 */
		analog->meaning->mqflags |= SR_MQFLAG_HOLD;
	if (info->is_max)
		analog->meaning->mqflags |= SR_MQFLAG_MAX;
	if (info->is_min)
		analog->meaning->mqflags |= SR_MQFLAG_MIN;
	if (info->is_rel)
		analog->meaning->mqflags |= SR_MQFLAG_RELATIVE;

	/* Other flags */
	if (info->is_batt)
		sr_spew("Battery is low.");
	if (info->is_auto_power)
		sr_spew("Auto-Power-Off enabled.");
}

static gboolean flags_valid(const struct vc870_info *info)
{
	(void)info;

	/* TODO: Implement. */
	return TRUE;
}

SR_PRIV gboolean sr_vc870_packet_valid(const uint8_t *buf)
{
	struct vc870_info info;

	/* Byte 21: Always '\r' (carriage return, 0x0d, 13) */
	/* Byte 22: Always '\n' (newline, 0x0a, 10) */
	if (buf[21] != '\r' || buf[22] != '\n')
		return FALSE;

	parse_flags(buf, &info);

	return flags_valid(&info);
}

SR_PRIV int sr_vc870_parse(const uint8_t *buf, float *floatval,
			   struct sr_datafeed_analog *analog, void *info)
{
	int ret, exponent = 0;
	struct vc870_info *info_local;

	info_local = info;
	memset(info_local, 0, sizeof(struct vc870_info));

	if (!sr_vc870_packet_valid(buf))
		return SR_ERR;

	parse_flags(buf, info_local);

	if ((ret = parse_value(buf, info_local, floatval)) != SR_OK) {
		sr_dbg("Error parsing value: %d.", ret);
		return ret;
	}

	if ((ret = parse_range(buf[2], floatval, &exponent, info_local)) != SR_OK)
		return ret;

	handle_flags(analog, floatval, info_local);

	analog->encoding->digits = -exponent;
	analog->spec->spec_digits = -exponent;

	return SR_OK;
}
Commit	Line	Data
c36f78f7 UH	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2014-2015 Uwe Hermann <uwe@hermann-uwe.de>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
2ea1fdf1	17	* along with this program; if not, see <http://www.gnu.org/licenses/>.
c36f78f7 UH	18	*/
c36f78f7 UH	19
6ec6c43b	20	#include <config.h>
c36f78f7 UH	21	#include <string.h>
	22	#include <ctype.h>
	23	#include <math.h>
	24	#include <glib.h>
c1aae900	25	#include <libsigrok/libsigrok.h>
c36f78f7 UH	26	#include "libsigrok-internal.h"
	27
	28	#define LOG_PREFIX "vc870"
	29
a66d44be AJ	30	/* Exponents for the respective measurement mode. */
	31	static const int exponents[][8] = {
	32	{ -4, -3, -2, -1, 0, 0, 0, 0 }, /* DCV */
	33	{ -3, -2, -1, 0, 0, 0, 0, 0 }, /* ACV */
	34	{ -5, 0, 0, 0, 0, 0, 0, 0 }, /* DCmV */
	35	{ -1, 0, 0, 0, 0, 0, 0, 0 }, /* Temperature (C) */
	36	// { -2, 0, 0, 0, 0, 0, 0, 0 }, /* TODO: Temperature (F) */
c36f78f7	37	/*
a66d44be	38	* Note: The sequence -1 -> 1 for the resistance
c36f78f7 UH	39	* value is correct and verified in practice!
	40	* Don't trust the vendor docs on this.
	41	*/
a66d44be AJ	42	{ -2, -1, 1, 2, 3, 4, 0, 0 }, /* Resistance */
	43	{ -2, 0, 0, 0, 0, 0, 0, 0 }, /* Continuity */
	44	{ -12, -11, -10, -9, -8, -7, -6, 0 }, /* Capacitance */
	45	{ -4, 0, 0, 0, 0, 0, 0, 0 }, /* Diode */
	46	{ -3, -2, -1, 0, 1, 2, 3, 4 }, /* Frequency */
	47	{ -2, 0, 0, 0, 0, 0, 0, 0 }, /* Loop current */
b4a0770e WS	48	/*
b4a0770e WS	49	* Note: Measurements showed that AC and DC differ
a66d44be	50	* in the exponents used, although docs say they should
b4a0770e WS	51	* be the same.
b4a0770e WS	52	*/
a66d44be AJ	53	{ -8, -7, 0, 0, 0, 0, 0, 0 }, /* DCµA */
	54	{ -7, -6, 0, 0, 0, 0, 0, 0 }, /* ACµA */
	55	{ -6, -5, 0, 0, 0, 0, 0, 0 }, /* DCmA */
	56	{ -5, -4, 0, 0, 0, 0, 0, 0 }, /* ACmA */
	57	{ -3, 0, 0, 0, 0, 0, 0, 0 }, /* DCA */
	58	/* TODO: Verify exponent for ACA */
	59	{ -3, 0, 0, 0, 0, 0, 0, 0 }, /* ACA */
	60	{ -1, 0, 0, 0, 0, 0, 0, 0 }, /* Act+apparent power */
	61	{ -3, 0, 0, 0, 0, 0, 0, 0 }, /* Power exponent / freq */
	62	{ -1, 0, 0, 0, 0, 0, 0, 0 }, /* V eff + A eff */
c36f78f7 UH	63	};
	64
	65	static int parse_value(const uint8_t buf, struct vc870_info info,
	66	float *result)
	67	{
	68	int i, intval;
c36f78f7 UH	69
	70	/* Bytes 3-7: Main display value (5 decimal digits) */
	71	if (info->is_open \|\| info->is_ol1) {
	72	sr_spew("Over limit.");
	73	*result = INFINITY;
	74	return SR_OK;
	75	} else if (!isdigit(buf[3]) \|\| !isdigit(buf[4]) \|\|
	76	!isdigit(buf[5]) \|\| !isdigit(buf[6]) \|\| !isdigit(buf[7])) {
	77	sr_dbg("Invalid digits: %02x %02x %02x %02x %02X "
6433156c DE	78	"(%c %c %c %c %c).",
	79	buf[3], buf[4], buf[5], buf[6], buf[7],
	80	buf[3], buf[4], buf[5], buf[6], buf[7]);
c36f78f7 UH	81	return SR_ERR;
	82	}
	83
	84	intval = 0;
	85	for (i = 0; i < 5; i++)
	86	intval = 10 * intval + (buf[i + 3] - '0'); /* Main display. */
	87	// intval = 10 * intval + (buf[i + 8] - '0'); /* TODO: Aux display. */
	88
	89	/* Apply sign. */
	90	intval *= info->is_sign1 ? -1 : 1;
	91	// intval = info->is_sign2 ? -1 : 1; / TODO: Fahrenheit / aux display. */
	92
c36f78f7 UH	93	/* Note: The decimal point position will be parsed later. */
c36f78f7 UH	94
b89462e4	95	sr_spew("The display value without comma is %05d.", intval);
c36f78f7	96
b89462e4	97	*result = (float)intval;
c36f78f7 UH	98
	99	return SR_OK;
	100	}
	101
a66d44be	102	static int parse_range(uint8_t b, float floatval, int exponent,
c36f78f7 UH	103	const struct vc870_info *info)
	104	{
	105	int idx, mode;
c36f78f7 UH	106
	107	idx = b - '0';
	108
	109	if (idx < 0 \|\| idx > 7) {
	110	sr_dbg("Invalid range byte / index: 0x%02x / 0x%02x.", b, idx);
	111	return SR_ERR;
	112	}
	113
	114	/* Parse range byte (depends on the measurement mode). */
	115	if (info->is_voltage && info->is_dc && !info->is_milli)
	116	mode = 0; /* DCV */
	117	else if (info->is_voltage && info->is_ac)
	118	mode = 1; /* ACV */
	119	else if (info->is_voltage && info->is_dc && info->is_milli)
	120	mode = 2; /* DCmV */
	121	else if (info->is_temperature)
	122	mode = 3; /* Temperature */
	123	else if (info->is_resistance \|\| info->is_continuity)
	124	mode = 4; /* Resistance */
	125	else if (info->is_continuity)
	126	mode = 5; /* Continuity */
	127	else if (info->is_capacitance)
	128	mode = 6; /* Capacitance */
	129	else if (info->is_diode)
	130	mode = 7; /* Diode */
	131	else if (info->is_frequency)
	132	mode = 8; /* Frequency */
	133	else if (info->is_loop_current)
	134	mode = 9; /* Loop current */
	135	else if (info->is_current && info->is_micro && info->is_dc)
	136	mode = 10; /* DCµA */
	137	else if (info->is_current && info->is_micro && info->is_ac)
	138	mode = 11; /* ACµA */
	139	else if (info->is_current && info->is_milli && info->is_dc)
	140	mode = 12; /* DCmA */
	141	else if (info->is_current && info->is_milli && info->is_ac)
	142	mode = 13; /* ACmA */
	143	else if (info->is_current && !info->is_milli && !info->is_micro && info->is_dc)
	144	mode = 14; /* DCA */
	145	else if (info->is_current && !info->is_milli && !info->is_micro && info->is_ac)
	146	mode = 15; /* ACA */
	147	else if (info->is_power_apparent_power)
	148	mode = 16; /* Act+apparent power */
	149	else if (info->is_power_factor_freq)
	150	mode = 17; /* Power factor / freq */
ee2e9be2	151	else if (info->is_v_a_rms_value)
c36f78f7 UH	152	mode = 18; /* V eff + A eff */
	153	else {
	154	sr_dbg("Invalid mode, range byte was: 0x%02x.", b);
	155	return SR_ERR;
	156	}
	157
a66d44be	158	*exponent = exponents[mode][idx];
c36f78f7	159
a66d44be AJ	160	/* Apply respective exponent (mode-dependent) on the value. */
	161	floatval = powf(10, *exponent);
	162	sr_dbg("Applying exponent %d, new value is %f.", exponent, floatval);
c36f78f7 UH	163
	164	return SR_OK;
	165	}
	166
	167	static void parse_flags(const uint8_t buf, struct vc870_info info)
	168	{
d9251a2c	169	/* Bytes 0/1: Function / function select */
c36f78f7 UH	170	/* Note: Some of these mappings are fixed up later. */
	171	switch (buf[0]) {
	172	case 0x30: /* DCV / ACV */
	173	info->is_voltage = TRUE;
	174	info->is_dc = (buf[1] == 0x30);
	175	info->is_ac = (buf[1] == 0x31);
	176	break;
	177	case 0x31: /* DCmV / Celsius */
	178	if (buf[1] == 0x30)
	179	info->is_voltage = info->is_milli = info->is_dc = TRUE;
	180	else if (buf[1] == 0x31)
	181	info->is_temperature = TRUE;
	182	break;
	183	case 0x32: /* Resistance / Short-circuit test */
	184	info->is_resistance = (buf[1] == 0x30);
	185	info->is_continuity = (buf[1] == 0x31);
	186	break;
	187	case 0x33: /* Capacitance */
	188	info->is_capacitance = (buf[1] == 0x30);
	189	break;
	190	case 0x34: /* Diode */
	191	info->is_diode = (buf[1] == 0x30);
	192	break;
	193	case 0x35: /* (4~20mA)% */
	194	info->is_frequency = (buf[1] == 0x30);
	195	info->is_loop_current = (buf[1] == 0x31);
	196	break;
	197	case 0x36: /* DCµA / ACµA */
	198	info->is_current = info->is_micro = TRUE;
	199	info->is_dc = (buf[1] == 0x30);
	200	info->is_ac = (buf[1] == 0x31);
	201	break;
	202	case 0x37: /* DCmA / ACmA */
	203	info->is_current = info->is_milli = TRUE;
	204	info->is_dc = (buf[1] == 0x30);
	205	info->is_ac = (buf[1] == 0x31);
	206	break;
	207	case 0x38: /* DCA / ACA */
	208	info->is_current = TRUE;
	209	info->is_dc = (buf[1] == 0x30);
	210	info->is_ac = (buf[1] == 0x31);
	211	break;
	212	case 0x39: /* Active power + apparent power / power factor + frequency */
	213	if (buf[1] == 0x30)
	214	/* Active power + apparent power */
	215	info->is_power_apparent_power = TRUE;
	216	else if (buf[1] == 0x31)
	217	/* Power factor + frequency */
	218	info->is_power_factor_freq = TRUE;
	219	else if (buf[1] == 0x32)
	220	/* Voltage effective value + current effective value */
ee2e9be2	221	info->is_v_a_rms_value = TRUE;
c36f78f7 UH	222	break;
	223	default:
	224	sr_dbg("Invalid function bytes: %02x %02x.", buf[0], buf[1]);
	225	break;
	226	}
	227
	228	/* Byte 2: Range */
	229
	230	/* Byte 3-7: Main display digits */
	231
	232	/* Byte 8-12: Auxiliary display digits */
	233
	234	/* Byte 13: TODO: "Simulate strip tens digit". */
	235
	236	/* Byte 14: TODO: "Simulate strip the single digit". */
	237
	238	/* Byte 15: Status */
	239	info->is_sign2 = (buf[15] & (1 << 3)) != 0;
	240	info->is_sign1 = (buf[15] & (1 << 2)) != 0;
	241	info->is_batt = (buf[15] & (1 << 1)) != 0; /* Bat. low */
	242	info->is_ol1 = (buf[15] & (1 << 0)) != 0; /* Overflow (main display) */
	243
	244	/* Byte 16: Option 1 */
	245	info->is_max = (buf[16] & (1 << 3)) != 0;
	246	info->is_min = (buf[16] & (1 << 2)) != 0;
	247	info->is_maxmin = (buf[16] & (1 << 1)) != 0;
	248	info->is_rel = (buf[16] & (1 << 0)) != 0;
	249
	250	/* Byte 17: Option 2 */
	251	info->is_ol2 = (buf[17] & (1 << 3)) != 0;
	252	info->is_open = (buf[17] & (1 << 2)) != 0;
	253	info->is_manu = (buf[17] & (1 << 1)) != 0; /* Manual mode */
	254	info->is_hold = (buf[17] & (1 << 0)) != 0; /* Hold */
	255
	256	/* Byte 18: Option 3 */
	257	info->is_light = (buf[18] & (1 << 3)) != 0;
	258	info->is_usb = (buf[18] & (1 << 2)) != 0; /* Always on */
	259	info->is_warning = (buf[18] & (1 << 1)) != 0; /* Never seen? */
	260	info->is_auto_power = (buf[18] & (1 << 0)) != 0; /* Always on */
	261
	262	/* Byte 19: Option 4 */
	263	info->is_misplug_warn = (buf[19] & (1 << 3)) != 0; /* Never gets set? */
	264	info->is_lo = (buf[19] & (1 << 2)) != 0;
	265	info->is_hi = (buf[19] & (1 << 1)) != 0;
	266	info->is_open2 = (buf[19] & (1 << 0)) != 0; /* TODO: Unknown. */
	267
	268	/* Byte 20: Dual display bit */
	269	info->is_dual_display = (buf[20] & (1 << 0)) != 0;
	270
	271	/* Byte 21: Always '\r' (carriage return, 0x0d, 13) */
	272
	273	/* Byte 22: Always '\n' (newline, 0x0a, 10) */
	274
	275	info->is_auto = !info->is_manu;
c36f78f7 UH	276	}
c36f78f7 UH	277
b02bb45f	278	static void handle_flags(struct sr_datafeed_analog *analog,
c36f78f7 UH	279	float floatval, const struct vc870_info info)
	280	{
	281	/*
	282	* Note: is_micro etc. are not used directly to multiply/divide
a66d44be	283	* floatval, this is handled via parse_range() and exponents[][].
c36f78f7 UH	284	*/
	285
	286	/* Measurement modes */
	287	if (info->is_voltage) {
b02bb45f UH	288	analog->meaning->mq = SR_MQ_VOLTAGE;
b02bb45f UH	289	analog->meaning->unit = SR_UNIT_VOLT;
c36f78f7 UH	290	}
c36f78f7 UH	291	if (info->is_current) {
b02bb45f UH	292	analog->meaning->mq = SR_MQ_CURRENT;
b02bb45f UH	293	analog->meaning->unit = SR_UNIT_AMPERE;
c36f78f7 UH	294	}
c36f78f7 UH	295	if (info->is_resistance) {
b02bb45f UH	296	analog->meaning->mq = SR_MQ_RESISTANCE;
b02bb45f UH	297	analog->meaning->unit = SR_UNIT_OHM;
c36f78f7 UH	298	}
c36f78f7 UH	299	if (info->is_frequency) {
b02bb45f UH	300	analog->meaning->mq = SR_MQ_FREQUENCY;
b02bb45f UH	301	analog->meaning->unit = SR_UNIT_HERTZ;
c36f78f7 UH	302	}
c36f78f7 UH	303	if (info->is_capacitance) {
b02bb45f UH	304	analog->meaning->mq = SR_MQ_CAPACITANCE;
b02bb45f UH	305	analog->meaning->unit = SR_UNIT_FARAD;
c36f78f7 UH	306	}
c36f78f7 UH	307	if (info->is_temperature) {
b02bb45f UH	308	analog->meaning->mq = SR_MQ_TEMPERATURE;
b02bb45f UH	309	analog->meaning->unit = SR_UNIT_CELSIUS;
c36f78f7	310	/* TODO: Handle Fahrenheit in auxiliary display. */
b02bb45f	311	// analog->meaning->unit = SR_UNIT_FAHRENHEIT;
c36f78f7 UH	312	}
c36f78f7 UH	313	if (info->is_continuity) {
b02bb45f UH	314	analog->meaning->mq = SR_MQ_CONTINUITY;
b02bb45f UH	315	analog->meaning->unit = SR_UNIT_BOOLEAN;
c36f78f7 UH	316	/* Vendor docs: "< 20 Ohm acoustic" */
	317	floatval = (floatval < 0.0 \|\| *floatval > 20.0) ? 0.0 : 1.0;
	318	}
	319	if (info->is_diode) {
b02bb45f UH	320	analog->meaning->mq = SR_MQ_VOLTAGE;
b02bb45f UH	321	analog->meaning->unit = SR_UNIT_VOLT;
c36f78f7 UH	322	}
	323	if (info->is_loop_current) {
	324	/* 4mA = 0%, 20mA = 100% */
b02bb45f UH	325	analog->meaning->mq = SR_MQ_CURRENT;
b02bb45f UH	326	analog->meaning->unit = SR_UNIT_PERCENTAGE;
c36f78f7 UH	327	}
c36f78f7 UH	328	if (info->is_power) {
b02bb45f UH	329	analog->meaning->mq = SR_MQ_POWER;
b02bb45f UH	330	analog->meaning->unit = SR_UNIT_WATT;
c36f78f7	331	}
c36f78f7	332	if (info->is_power_apparent_power) {
b02bb45f UH	333	analog->meaning->mq = SR_MQ_POWER;
b02bb45f UH	334	analog->meaning->unit = SR_UNIT_WATT;
c36f78f7	335	/* TODO: Handle apparent power. */
b02bb45f UH	336	// analog->meaning->mq = SR_MQ_APPARENT_POWER;
b02bb45f UH	337	// analog->meaning->unit = SR_UNIT_VOLT_AMPERE;
c36f78f7	338	}
4867dd17	339	if (info->is_power_factor_freq) {
b02bb45f UH	340	analog->meaning->mq = SR_MQ_POWER_FACTOR;
b02bb45f UH	341	analog->meaning->unit = SR_UNIT_UNITLESS;
2e1c4817	342	/* TODO: Handle frequency. */
b02bb45f UH	343	// analog->meaning->mq = SR_MQ_FREQUENCY;
b02bb45f UH	344	// analog->meaning->unit = SR_UNIT_HERTZ;
4867dd17	345	}
ee2e9be2	346	if (info->is_v_a_rms_value) {
b02bb45f UH	347	analog->meaning->mqflags \|= SR_MQFLAG_RMS;
	348	analog->meaning->mq = SR_MQ_VOLTAGE;
	349	analog->meaning->unit = SR_UNIT_VOLT;
ee2e9be2	350	/* TODO: Handle effective current value */
b02bb45f UH	351	// analog->meaning->mq = SR_MQ_CURRENT;
b02bb45f UH	352	// analog->meaning->unit = SR_UNIT_AMPERE;
ee2e9be2	353	}
c36f78f7 UH	354
	355	/* Measurement related flags */
	356	if (info->is_ac)
b02bb45f	357	analog->meaning->mqflags \|= SR_MQFLAG_AC;
c36f78f7	358	if (info->is_dc)
b02bb45f	359	analog->meaning->mqflags \|= SR_MQFLAG_DC;
c36f78f7	360	if (info->is_auto)
b02bb45f	361	analog->meaning->mqflags \|= SR_MQFLAG_AUTORANGE;
c36f78f7	362	if (info->is_diode)
64aa214a	363	analog->meaning->mqflags \|= SR_MQFLAG_DIODE \| SR_MQFLAG_DC;
c36f78f7 UH	364	if (info->is_hold)
	365	/*
	366	* Note: HOLD only affects the number displayed on the LCD,
	367	* but not the value sent via the protocol! It also does not
	368	* affect the bargraph on the LCD.
	369	*/
b02bb45f	370	analog->meaning->mqflags \|= SR_MQFLAG_HOLD;
c36f78f7	371	if (info->is_max)
b02bb45f	372	analog->meaning->mqflags \|= SR_MQFLAG_MAX;
c36f78f7	373	if (info->is_min)
b02bb45f	374	analog->meaning->mqflags \|= SR_MQFLAG_MIN;
c36f78f7	375	if (info->is_rel)
b02bb45f	376	analog->meaning->mqflags \|= SR_MQFLAG_RELATIVE;
c36f78f7 UH	377
	378	/* Other flags */
	379	if (info->is_batt)
	380	sr_spew("Battery is low.");
	381	if (info->is_auto_power)
	382	sr_spew("Auto-Power-Off enabled.");
	383	}
	384
	385	static gboolean flags_valid(const struct vc870_info *info)
	386	{
c35276dd UH	387	(void)info;
c35276dd UH	388
c36f78f7 UH	389	/* TODO: Implement. */
	390	return TRUE;
	391	}
	392
	393	SR_PRIV gboolean sr_vc870_packet_valid(const uint8_t *buf)
	394	{
	395	struct vc870_info info;
	396
	397	/* Byte 21: Always '\r' (carriage return, 0x0d, 13) */
	398	/* Byte 22: Always '\n' (newline, 0x0a, 10) */
	399	if (buf[21] != '\r' \|\| buf[22] != '\n')
	400	return FALSE;
	401
	402	parse_flags(buf, &info);
	403
	404	return flags_valid(&info);
	405	}
	406
	407	SR_PRIV int sr_vc870_parse(const uint8_t buf, float floatval,
b02bb45f	408	struct sr_datafeed_analog analog, void info)
c36f78f7	409	{
a66d44be	410	int ret, exponent = 0;
c36f78f7 UH	411	struct vc870_info *info_local;
c36f78f7 UH	412
94b1d506	413	info_local = info;
c36f78f7 UH	414	memset(info_local, 0, sizeof(struct vc870_info));
	415
	416	if (!sr_vc870_packet_valid(buf))
	417	return SR_ERR;
	418
	419	parse_flags(buf, info_local);
	420
	421	if ((ret = parse_value(buf, info_local, floatval)) != SR_OK) {
	422	sr_dbg("Error parsing value: %d.", ret);
	423	return ret;
	424	}
	425
a66d44be	426	if ((ret = parse_range(buf[2], floatval, &exponent, info_local)) != SR_OK)
c36f78f7 UH	427	return ret;
	428
	429	handle_flags(analog, floatval, info_local);
	430
d9251a2c	431	analog->encoding->digits = -exponent;
a66d44be AJ	432	analog->spec->spec_digits = -exponent;
a66d44be AJ	433
c36f78f7 UH	434	return SR_OK;
c36f78f7 UH	435	}