--- /dev/null
+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2019 Gerhard Sittig <gerhard.sittig@gmx.net>
+ *
+ * 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 3 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 <glib.h>
+#include <libsigrok/libsigrok.h>
+#include "libsigrok-internal.h"
+#include <math.h>
+#include <stdint.h>
+#include <string.h>
+
+#define LOG_PREFIX "vc4080"
+
+#ifdef HAVE_SERIAL_COMM
+
+/**
+ * @file Packet parser for Voltcraft 4080 LCR meters.
+ */
+
+/*
+ * Developer notes on the protocol and the implementation:
+ *
+ * The LCR meter is connected to a serial port (1200/7e1). The protocol
+ * is text based (printables plus some line termination), is accessible
+ * to interactive exploration in a terminal. Requests differ in length
+ * (single character, or sequence of seven characters in brackets).
+ * Responses either have 14 (setup) or 39 (measurement) characters.
+ * Thus the protocol lends itself to integration with the serial-lcr
+ * driver. Setup is handled outside of the acquisition loop, and all
+ * measurement results are of equal length and end in a termination
+ * that we can synchronize to. Requesting packets from the meter is
+ * similar to serial-dmm operation.
+ *
+ * Quick notes for our parser's purposes:
+ *
+ * pkt[0] 'L'/'C'/'R'
+ * pkt[1] 'Q'/'D'/'R'
+ * pkt[2] 'A'/'B' output frequency
+ * pkt[3] 'P'/'S' circuit model
+ * pkt[4] 'A'/'M' auto/manual
+ *
+ * pkt[5:9] main display value in text format, '8' switching range, '9' OL
+ * pkt[10] main display range, '0'-'6', depends on RLC and freq and ser/par
+ *
+ * pkt[11:14] secondary display value in text format, '9' OL
+ * pkt[15] secondary display range, '1'-'5', depends on QDR and Rs value
+ *
+ * pkt[16] packet sequence counter, cycling through '0'-'9'
+ *
+ * pkt[17:20] D value in text form, '9' OL
+ * pkt[21] D range
+ *
+ * pkt[22:25] Q value in text form, '9' OL
+ * pkt[26] Q range
+ *
+ * pkt[27] 'S'/'_', SETup(?)
+ * pkt[28] 'F'/'_', FUSE
+ * pkt[29] 'H'/'_', HOLD
+ * pkt[30] 'R' (present value), 'M' (max), 'I' (min), 'A' (avg),
+ * 'X' (max - min), '_' (normal)
+ * pkt[31] 'R' (REL), 'S' (REL SET), '_' (normal)
+ * pkt[32] 'L' (LIMITS), '_' (normal)
+ * pkt[33] 'T' (TOL), 'S' (TOL SET), '_' (normal)
+ * pkt[34] 'B' (backlight), '_' (normal)
+ * pkt[35] 'A' (adapter inserted(?)), '_' (normal)
+ * pkt[36] 'B' (low battery), '_' (normal)
+ *
+ * pkt[37] always CR (\r)
+ * pkt[38] always LF (\n)
+ *
+ * Example packet, PeakTech 2165, 1200/8n1 and parity bit stripped:
+ *
+ * L Q A P A 9 0 0 0 0 6 1 4 0 6 2 1 0 7 1 1 4 1 4 0 6 2 _ _ _ _ _ _ _ _ _ _ CR LF
+ * 0 5 10 15 20 25 30 35 38
+ *
+ * Another example, resistance mode, 1k probed:
+ *
+ * 52 5f 42 5f 41 30 39 39 33 30 32 30 30 30 30 39 33 37 34 35 36 31 30 30 31 33 34 5f 5f 5f 5f 5f 5f 5f 5f 5f 5f 0d 0a
+ * R _ B _ A 09930 2 00009 3 7456 1 0013 4 __________ CR/LF
+ *
+ * Another example, C mode:
+ *
+ * 43 51 42 53 4d 30 39 38 39 31 35 30 30 31 33 34 31 37 35 38 33 31 30 30 31 33 34 5f 5f 5f 5f 5f 5f 5f 5f 5f 5f 0d 0a
+ * C Q B S M 09891 5 00134 1 7583 1 0013 4 ____...
+ * C, Q, 120, ser, man, 09891 @2000uF -> C = 989.1uF, 00134 -> Q = 13.4
+ *
+ * 43 51 42 53 4d 30 39 38 38 30 35 30 30 31 33 34 34 37 35 37 34 31 30 30 31 33 34 5f 5f 5f 5f 5f 5f 5f 42 5f 5f 0d 0a
+ * 900uF (main)
+ *
+ * For more details see Conrad's summary document and PeakTech's manual:
+ * http://www.produktinfo.conrad.com/datenblaetter/100000-124999/121064-da-01-en-Schnittstellenbeschr_LCR_4080_Handmessg.pdf
+ * http://peaktech.de/productdetail/kategorie/lcr-messer/produkt/p-2165.html?file=tl_files/downloads/2001%20-%203000/PeakTech_2165_USB.pdf
+ *
+ * TODO
+ * - Check response lengths. Are line terminators involved during setup?
+ * - Check parity. Does FT232R not handle parity correctly? Neither 7e1 (as
+ * documented) nor 7o1 (for fun) worked. 8n1 provided data but contained
+ * garbage (LCR driver needs to strip off the parity bit?).
+ * - Determine whether the D and Q channels are required. It seems that
+ * every LCR packet has space to provide these values, but we may as well
+ * get away with just two channels, since users can select D and Q to be
+ * shown in the secondary display. It's yet uncertain whether the D and Q
+ * values in the packets are meaningful when the meter is not in the D/Q
+ * measurement mode.
+ */
+
+/*
+ * Supported output frequencies and equivalent circuit models. A helper
+ * for the packet parser (accepting a "code" for the property, regardless
+ * of its position in the LCR packet), and a list for capability queries.
+ * Concentrated in a single spot to remain aware duing maintenance.
+ */
+
+static const double frequencies[] = {
+ SR_HZ(120), SR_KHZ(1),
+};
+
+static uint64_t get_frequency(char code)
+{
+ switch (code) {
+ case 'A': return SR_KHZ(1);
+ case 'B': return SR_HZ(120);
+ default: return 0;
+ }
+}
+
+enum equiv_model { MODEL_PAR, MODEL_SER, MODEL_NONE, };
+
+static const char *const circuit_models[] = {
+ "PARALLEL", "SERIES", "NONE",
+};
+
+static enum equiv_model get_equiv_model(char lcr_code, char model_code)
+{
+ switch (lcr_code) {
+ case 'L': /* EMPTY */ break;
+ case 'C': /* EMPTY */ break;
+ case 'R': return MODEL_NONE;
+ default: return MODEL_NONE;
+ }
+ switch (model_code) {
+ case 'P': return MODEL_PAR;
+ case 'S': return MODEL_SER;
+ default: return MODEL_NONE;
+ }
+}
+
+static const char *get_equiv_model_text(enum equiv_model model)
+{
+ return circuit_models[model];
+}
+
+/*
+ * Packet parse routine and its helpers. Depending on the specific layout
+ * of the meter's packet which communicates measurement results. Some of
+ * them are also used outside of strict packet parsing for value extraction.
+ */
+
+static uint64_t parse_freq(const uint8_t *pkt)
+{
+ return get_frequency(pkt[2]);
+}
+
+static const char *parse_model(const uint8_t *pkt)
+{
+ return get_equiv_model_text(get_equiv_model(pkt[0], pkt[3]));
+}
+
+static float parse_number(const uint8_t *digits, size_t length)
+{
+ char value_text[8];
+ float number;
+ int ret;
+
+ memcpy(value_text, digits, length);
+ value_text[length] = '\0';
+ ret = sr_atof_ascii(value_text, &number);
+
+ return (ret == SR_OK) ? number : 0;
+}
+
+/*
+ * Conrad's protocol description suggests that:
+ * - The main display's LCR selection, output frequency, and range
+ * result in an Rs value in the 100R to 100k range, in addition to
+ * the main display's scale for the value.
+ * - The secondary display's DQR selection, the above determined Rs
+ * value, and range result in the value's scale.
+ * - The D and Q values' range seems to follow the secondary display's
+ * logic.
+ */
+
+enum lcr_kind { LCR_NONE, LCR_IS_L, LCR_IS_C, LCR_IS_R, };
+enum dqr_kind { DQR_NONE, DQR_IS_D, DQR_IS_Q, DQR_IS_R, };
+
+static int get_main_scale_rs(int *digits, int *rs,
+ uint8_t range, enum lcr_kind lcr, uint64_t freq)
+{
+ /*
+ * Scaling factors for values. Digits count for 20000 full scale.
+ * Full scale values for different modes are:
+ * R: 20R, 200R, 2k, 20k, 200k, 2M, 10M
+ * L 1kHz: 2mH, 20mH, 200mH, 2H, 20H, 200H, 1000H
+ * L 120Hz: 20mH, 200mH, 2H, 20H, 200H, 2kH, 10kH
+ * C 1kHz: 2nF, 20nF, 200nF, 2uF, 20uF, 200uF, 2mF
+ * C 120Hz: 20nF, 200nF, 2unF, 20uF, 200uF, 2muF, 20mF
+ */
+ static const int dig_r[] = { -3, -2, -1, +0, +1, +2, +3, };
+ static const int dig_l_1k[] = { -7, -6, -5, -4, -3, -2, -1, };
+ static const int dig_l_120[] = { -6, -5, -4, -3, -2, -1, 0, };
+ static const int dig_c_1k[] = { -13, -12, -11, -10, -9, -8, -7, };
+ static const int dig_c_120[] = { -12, -11, -10, -9, -8, -7, -6, };
+ /*
+ * Rs values for the scale, depending on LCR mode.
+ * Values for R/L: 100R, 100R, 100R, 1k, 10k, 100k, 100k
+ * Values for C: 100k, 100k, 10k, 1k, 100R, 100R, 100R
+ */
+ static const int rs_r_l[] = {
+ 100, 100, 100, 1000, 10000, 100000, 100000,
+ };
+ static const int rs_c[] = {
+ 100000, 100000, 10000, 1000, 100, 100, 100,
+ };
+
+ const int *digits_table, *rs_table;
+
+ /* The 'range' input value is only valid between 0..6. */
+ if (range > 6)
+ return SR_ERR_DATA;
+
+ if (lcr == LCR_IS_R) {
+ digits_table = dig_r;
+ rs_table = rs_r_l;
+ } else if (lcr == LCR_IS_L && freq == SR_KHZ(1)) {
+ digits_table = dig_l_1k;
+ rs_table = rs_r_l;
+ } else if (lcr == LCR_IS_L && freq == SR_HZ(120)) {
+ digits_table = dig_l_120;
+ rs_table = rs_r_l;
+ } else if (lcr == LCR_IS_C && freq == SR_KHZ(1)) {
+ digits_table = dig_c_1k;
+ rs_table = rs_c;
+ } else if (lcr == LCR_IS_C && freq == SR_HZ(120)) {
+ digits_table = dig_c_120;
+ rs_table = rs_c;
+ } else {
+ return SR_ERR_DATA;
+ }
+
+ if (digits)
+ *digits = digits_table[range];
+ if (rs)
+ *rs = rs_table[range];
+
+ return SR_OK;
+}
+
+static int get_sec_scale(int *digits, uint8_t range, enum dqr_kind dqr, int rs)
+{
+ static const int dig_d_q[] = { 0, -1, -2, -3, -4, 0, };
+ static const int dig_r_100[] = { 0, -2, -1, +0, +1, 0, };
+ static const int dig_r_1k_10k[] = { 0, -2, -1, +0, +1, +2, };
+ static const int dig_r_100k[] = { 0, 0, -1, +0, +1, +2, };
+
+ const int *digits_table;
+
+ /*
+ * Absolute 'range' limits are 1..5, some modes have additional
+ * invalid positions (these get checked below).
+ */
+ if (range < 1 || range > 5)
+ return SR_ERR_DATA;
+
+ if (dqr == DQR_IS_D || dqr == DQR_IS_Q) {
+ if (range > 4)
+ return SR_ERR_DATA;
+ digits_table = dig_d_q;
+ } else if (dqr == DQR_IS_R && rs == 100) {
+ if (range > 4)
+ return SR_ERR_DATA;
+ digits_table = dig_r_100;
+ } else if (dqr == DQR_IS_R && (rs == 1000 || rs == 10000)) {
+ digits_table = dig_r_1k_10k;
+ } else if (dqr == DQR_IS_R && rs == 100000) {
+ if (range < 2)
+ return SR_ERR_DATA;
+ digits_table = dig_r_100k;
+ } else {
+ return SR_ERR_DATA;
+ }
+
+ if (digits)
+ *digits = digits_table[range];
+
+ return SR_OK;
+}
+
+static void parse_measurement(const uint8_t *pkt, float *floatval,
+ struct sr_datafeed_analog *analog, size_t disp_idx)
+{
+ enum lcr_kind lcr;
+ enum dqr_kind dqr;
+ uint64_t freq;
+ enum equiv_model model;
+ gboolean is_auto, main_ranging, main_ol, sec_ol, d_ol, q_ol;
+ float main_value, sec_value, d_value, q_value;
+ char main_range, sec_range, d_range, q_range;
+ gboolean is_hold, is_relative, has_adapter, is_lowbatt;
+ enum minmax_kind {
+ MINMAX_MAX, MINMAX_MIN, MINMAX_SPAN,
+ MINMAX_AVG, MINMAX_CURR, MINMAX_NONE,
+ } minmax;
+ gboolean is_parallel;
+ int mq, mqflags, unit;
+ float value;
+ int digits, exponent;
+ gboolean ol, invalid;
+ int ret, rs, main_digits, sec_digits, d_digits, q_digits;
+ int main_invalid, sec_invalid, d_invalid, q_invalid;
+
+ /* Prepare void return values for error paths. */
+ analog->meaning->mq = 0;
+ analog->meaning->mqflags = 0;
+ if (disp_idx >= VC4080_CHANNEL_COUNT)
+ return;
+
+ /*
+ * The interpretation of secondary displays may depend not only
+ * on the meter's status (indicator flags), but also on the main
+ * display's current value (ranges, scaling). Unconditionally
+ * inspect most of the packet's content, regardless of which
+ * display we are supposed to extract the value for in this
+ * invocation.
+ *
+ * While we are converting the input text, check a few "fatal"
+ * conditions early, cease further packet inspection when the
+ * value is unstable or not yet available, or when the meter's
+ * current mode/function is not supported by this LCR parser.
+ */
+ switch (pkt[0]) {
+ case 'L': lcr = LCR_IS_L; break;
+ case 'R': lcr = LCR_IS_R; break;
+ case 'C': lcr = LCR_IS_C; break;
+ default: return;
+ }
+ switch (pkt[1]) {
+ case 'D': dqr = DQR_IS_D; break;
+ case 'Q': dqr = DQR_IS_Q; break;
+ case 'R': dqr = DQR_IS_R; break;
+ case '_': dqr = DQR_NONE; break; /* Can be valid, like in R mode. */
+ default: return;
+ }
+ freq = get_frequency(pkt[2]);
+ model = get_equiv_model(pkt[0], pkt[3]);
+ is_auto = pkt[4] == 'A';
+ main_ranging = pkt[5] == '8';
+ if (main_ranging) /* Switching ranges. */
+ return;
+ main_ol = pkt[5] == '9';
+ main_value = parse_number(&pkt[5], 5);
+ main_range = pkt[10];
+ if (main_range < '0' || main_range > '6')
+ main_range = '9';
+ main_range -= '0';
+ /*
+ * Contrary to the documentation, there have been valid four-digit
+ * values in the secondary display which start with '9'. Let's not
+ * consider these as overflown. Out-of-range 'range' specs for the
+ * secondary display will also invalidate these values.
+ */
+ sec_ol = 0 && pkt[11] == '9';
+ sec_value = parse_number(&pkt[11], 4);
+ sec_range = pkt[15];
+ if (sec_range < '0' || sec_range > '6')
+ sec_range = '9';
+ sec_range -= '0';
+ d_ol = pkt[17] == '9';
+ d_value = parse_number(&pkt[17], 4);
+ d_range = pkt[21];
+ if (d_range < '0' || d_range > '6')
+ d_range = '9';
+ d_range -= '0';
+ q_ol = pkt[22] == '9';
+ q_value = parse_number(&pkt[22], 4);
+ q_range = pkt[26];
+ if (q_range < '0' || q_range > '6')
+ q_range = '9';
+ d_range -= '0';
+ switch (pkt[27]) {
+ case 'S': return; /* Setup mode. Not supported. */
+ case '_': /* EMPTY */ break;
+ default: return; /* Unknown. */
+ }
+ is_hold = pkt[29] == 'H';
+ switch (pkt[30]) { /* Min/max modes. */
+ case 'R': minmax = MINMAX_CURR; break; /* Live reading. */
+ case 'M': minmax = MINMAX_MAX; break;
+ case 'I': minmax = MINMAX_MIN; break;
+ case 'X': minmax = MINMAX_SPAN; break; /* "Max - min" difference. */
+ case 'A': minmax = MINMAX_AVG; break;
+ case '_': minmax = MINMAX_NONE; break;
+ default: return; /* Unknown. */
+ }
+ if (minmax == MINMAX_SPAN) /* Not supported. */
+ return;
+ if (minmax == MINMAX_CURR) /* Normalize. */
+ minmax = MINMAX_NONE;
+ switch (pkt[31]) {
+ case 'R': is_relative = TRUE; break;
+ case 'S': return; /* Relative setup. Not supported. */
+ /* TODO Is this SR_MQFLAG_REFERENCE? */
+ case '_': is_relative = FALSE; break;
+ default: return; /* Unknown. */
+ }
+ if (pkt[32] != '_') /* Limits. Not supported. */
+ return;
+ if (pkt[33] != '_') /* Tolerance. Not supported. */
+ return;
+ has_adapter = pkt[35] == 'A';
+ is_lowbatt = pkt[36] == 'B';
+
+ /*
+ * Always need to inspect the main display's properties, to
+ * determine how to interpret the secondary displays.
+ */
+ rs = main_digits = sec_digits = d_digits = q_digits = 0;
+ main_invalid = sec_invalid = d_invalid = q_invalid = 0;
+ ret = get_main_scale_rs(&main_digits, &rs, main_range, lcr, freq);
+ if (ret != SR_OK)
+ main_invalid = 1;
+ ret = get_sec_scale(&sec_digits, sec_range, dqr, rs);
+ if (ret != SR_OK)
+ sec_invalid = 1;
+ ret = get_sec_scale(&d_digits, d_range, dqr, rs);
+ if (ret != SR_OK)
+ d_invalid = 1;
+ ret = get_sec_scale(&q_digits, q_range, dqr, rs);
+ if (ret != SR_OK)
+ q_invalid = 1;
+
+ /* Determine the measurement value and its units. Apply scaling. */
+ is_parallel = model == MODEL_PAR;
+ mq = 0;
+ mqflags = 0;
+ unit = 0;
+ switch (disp_idx) {
+ case VC4080_DISPLAY_PRIMARY:
+ invalid = main_invalid;
+ if (invalid)
+ break;
+ if (lcr == LCR_IS_L) {
+ mq = is_parallel
+ ? SR_MQ_PARALLEL_INDUCTANCE
+ : SR_MQ_SERIES_INDUCTANCE;
+ unit = SR_UNIT_HENRY;
+ } else if (lcr == LCR_IS_C) {
+ mq = is_parallel
+ ? SR_MQ_PARALLEL_CAPACITANCE
+ : SR_MQ_SERIES_CAPACITANCE;
+ unit = SR_UNIT_FARAD;
+ } else if (lcr == LCR_IS_R) {
+ mq = is_parallel
+ ? SR_MQ_PARALLEL_RESISTANCE
+ : SR_MQ_SERIES_RESISTANCE;
+ unit = SR_UNIT_OHM;
+ }
+ value = main_value;
+ ol = main_ol;
+ digits = 0;
+ exponent = main_digits;
+ break;
+ case VC4080_DISPLAY_SECONDARY:
+ invalid = sec_invalid;
+ if (invalid)
+ break;
+ if (dqr == DQR_IS_D) {
+ mq = SR_MQ_DISSIPATION_FACTOR;
+ unit = SR_UNIT_UNITLESS;
+ } else if (dqr == DQR_IS_Q) {
+ mq = SR_MQ_QUALITY_FACTOR;
+ unit = SR_UNIT_UNITLESS;
+ } else if (dqr == DQR_IS_R) {
+ mq = SR_MQ_RESISTANCE;
+ unit = SR_UNIT_OHM;
+ }
+ value = sec_value;
+ ol = sec_ol;
+ digits = 0;
+ exponent = sec_digits;
+ break;
+#if VC4080_WITH_DQ_CHANS
+ case VC4080_DISPLAY_D_VALUE:
+ invalid = d_invalid;
+ if (invalid)
+ break;
+ mq = SR_MQ_DISSIPATION_FACTOR;
+ unit = SR_UNIT_UNITLESS;
+ value = d_value;
+ ol = d_ol;
+ digits = 4;
+ exponent = d_digits;
+ break;
+ case VC4080_DISPLAY_Q_VALUE:
+ invalid = q_invalid;
+ if (invalid)
+ break;
+ mq = SR_MQ_QUALITY_FACTOR;
+ unit = SR_UNIT_UNITLESS;
+ value = q_value;
+ ol = q_ol;
+ digits = 4;
+ exponent = q_digits;
+ break;
+#else
+ (void)d_invalid;
+ (void)d_value;
+ (void)d_ol;
+ (void)d_digits;
+ (void)q_invalid;
+ (void)q_value;
+ (void)q_ol;
+ (void)q_digits;
+#endif
+ default:
+ /* ShouldNotHappen(TM). Won't harm either. Silences warnings. */
+ return;
+ }
+ if (invalid)
+ return;
+ if (is_auto)
+ mqflags |= SR_MQFLAG_AUTORANGE;
+ if (is_hold)
+ mqflags |= SR_MQFLAG_HOLD;
+ if (is_relative)
+ mqflags |= SR_MQFLAG_RELATIVE;
+ if (has_adapter)
+ mqflags |= SR_MQFLAG_FOUR_WIRE;
+ switch (minmax) {
+ case MINMAX_MAX:
+ mqflags |= SR_MQFLAG_MAX;
+ break;
+ case MINMAX_MIN:
+ mqflags |= SR_MQFLAG_MIN;
+ break;
+ case MINMAX_SPAN:
+ mqflags |= SR_MQFLAG_MAX | SR_MQFLAG_RELATIVE;
+ break;
+ case MINMAX_AVG:
+ mqflags |= SR_MQFLAG_AVG;
+ break;
+ case MINMAX_CURR:
+ case MINMAX_NONE:
+ default:
+ /* EMPTY */
+ break;
+ }
+
+ /* "Commit" the resulting value. */
+ if (ol) {
+ value = INFINITY;
+ } else {
+ value *= powf(10, exponent);
+ digits -= exponent;
+ }
+ *floatval = value;
+ analog->meaning->mq = mq;
+ analog->meaning->mqflags = mqflags;
+ analog->meaning->unit = unit;
+ analog->encoding->digits = digits;
+ analog->spec->spec_digits = digits;
+
+ /* Low battery is rather severe, the measurement could be invalid. */
+ if (is_lowbatt)
+ sr_warn("Low battery.");
+}
+
+/*
+ * Workaround for cables' improper(?) parity handling.
+ * TODO Should this move to serial-lcr or even common libsigrok code?
+ *
+ * Implementor's note: Serial communication is documented to be 1200/7e1.
+ * But practial setups with the shipped FT232R cable received no response
+ * at all with these settings. The 8n1 configuration resulted in responses
+ * while the LCR meter's packet parser then needs to strip the parity bits.
+ *
+ * Let's run this slightly modified setup for now, until more cables and
+ * compatible devices got observed and the proper solution gets determined.
+ * This cheat lets us receive measurement data right now. Stripping the
+ * parity bits off the packet bytes here in the parser is an idempotent
+ * operation that happens to work during stream detect as well as in the
+ * acquisition loop. It helps in the 8n1 configuration, and keeps working
+ * transparently in the 7e1 configuration, too. No harm is done, and the
+ * initial device support is achieved.
+ *
+ * By coincidence, the 'N' command which requests the next measurement
+ * value happens to conform with the 7e1 frame format (0b_0100_1110
+ * byte value). When the SETUP commands are supposed to work with this
+ * LCR meter as well, then the serial-lcr driver's TX data and RX data
+ * probably needs to pass LCR chip specific transformation routines,
+ * if the above mentioned parity support in serial cables issue has not
+ * yet been resolved.
+ */
+
+static void strip_parity_bit(uint8_t *p, size_t l)
+{
+ while (l--)
+ *p++ &= ~0x80;
+}
+
+/* LCR packet parser's public API. */
+
+SR_PRIV const char *vc4080_channel_formats[VC4080_CHANNEL_COUNT] = {
+ "P1", "P2",
+#if VC4080_WITH_DQ_CHANS
+ "D", "Q",
+#endif
+};
+
+SR_PRIV int vc4080_packet_request(struct sr_serial_dev_inst *serial)
+{
+ static const char *command = "N";
+
+ serial_write_blocking(serial, command, strlen(command), 0);
+
+ return SR_OK;
+}
+
+SR_PRIV gboolean vc4080_packet_valid(const uint8_t *pkt)
+{
+ /* Workaround for funny serial cables. */
+ strip_parity_bit((void *)pkt, VC4080_PACKET_SIZE);
+
+ /* Fixed CR/LF terminator. */
+ if (pkt[37] != '\r' || pkt[38] != '\n')
+ return FALSE;
+
+ return TRUE;
+}
+
+SR_PRIV int vc4080_packet_parse(const uint8_t *pkt, float *val,
+ struct sr_datafeed_analog *analog, void *info)
+{
+ struct lcr_parse_info *parse_info;
+
+ /* Workaround for funny serial cables. */
+ strip_parity_bit((void *)pkt, VC4080_PACKET_SIZE);
+
+ parse_info = info;
+ if (!parse_info->ch_idx) {
+ parse_info->output_freq = parse_freq(pkt);
+ parse_info->circuit_model = parse_model(pkt);
+ }
+ if (val && analog)
+ parse_measurement(pkt, val, analog, parse_info->ch_idx);
+
+ return SR_OK;
+}
+
+/*
+ * These are the get/set/list routines for the _chip_ specific parameters,
+ * the _device_ driver resides in src/hardware/serial-lcr/ instead.
+ */
+
+SR_PRIV int vc4080_config_list(uint32_t key, GVariant **data,
+ const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
+{
+
+ (void)sdi;
+ (void)cg;
+
+ switch (key) {
+ case SR_CONF_OUTPUT_FREQUENCY:
+ *data = g_variant_new_fixed_array(G_VARIANT_TYPE_DOUBLE,
+ ARRAY_AND_SIZE(frequencies), sizeof(frequencies[0]));
+ return SR_OK;
+ case SR_CONF_EQUIV_CIRCUIT_MODEL:
+ *data = g_variant_new_strv(ARRAY_AND_SIZE(circuit_models));
+ return SR_OK;
+ default:
+ return SR_ERR_NA;
+ }
+ /* UNREACH */
+}
+
+#endif
projects / libsigrok.git / commitdiff