]> sigrok.org Git - libsigrok.git/blame - src/dmm/vc870.c
Fix a few "value never read" scan-build warnings.
[libsigrok.git] / src / dmm / vc870.c
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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
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
6ec6c43b 21#include <config.h>
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22#include <string.h>
23#include <ctype.h>
24#include <math.h>
25#include <glib.h>
c1aae900 26#include <libsigrok/libsigrok.h>
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27#include "libsigrok-internal.h"
28
29#define LOG_PREFIX "vc870"
30
31/* Factors for the respective measurement mode (0 means "invalid"). */
32static const float factors[][8] = {
33 {1e-4, 1e-3, 1e-2, 1e-1, 0, 0, 0, 0}, /* DCV */
34 {1e-3, 1e-2, 1e-1, 1, 0, 0, 0, 0}, /* ACV */
35 {1e-5, 0, 0, 0, 0, 0, 0, 0}, /* DCmV */
36 {1e-1, 0, 0, 0, 0, 0, 0, 0}, /* Temperature (C) */
37// {1e-2, 0, 0, 0, 0, 0, 0, 0}, /* TODO: Temperature (F) */
38 /*
39 * Note: The sequence 1e-1 -> 1e1 for the resistance
40 * value is correct and verified in practice!
41 * Don't trust the vendor docs on this.
42 */
43 {1e-2, 1e-1, 1e1, 1e2, 1e3, 1e4, 0, 0}, /* Resistance */
44 {1e-2, 0, 0, 0, 0, 0, 0, 0}, /* Continuity */
45 {1e-12, 1e-11, 1e-10, 1e-9, 1e-8, 1e-7, 1e-6, 0}, /* Capacitance */
46 {1e-4, 0, 0, 0, 0, 0, 0, 0}, /* Diode */
47 {1e-3, 1e-2, 1e-1, 1, 1e1, 1e2, 1e3, 1e4}, /* Frequency */
48 {1e-2, 0, 0, 0, 0, 0, 0, 0}, /* Loop current */
49 {1e-8, 1e-7, 0, 0, 0, 0, 0, 0}, /* DCµA */
50 {1e-8, 1e-7, 0, 0, 0, 0, 0, 0}, /* ACµA */
51 {1e-6, 1e-5, 0, 0, 0, 0, 0, 0}, /* DCmA */
52 {1e-6, 1e-5, 0, 0, 0, 0, 0, 0}, /* ACmA */
53 {1e-3, 0, 0, 0, 0, 0, 0, 0}, /* DCA */
54 {1e-3, 0, 0, 0, 0, 0, 0, 0}, /* ACA */
55 {1e-1, 0, 0, 0, 0, 0, 0, 0}, /* Act+apparent power */
56 {1e-1, 0, 0, 0, 0, 0, 0, 0}, /* Power factor / freq */
57 {1e-1, 0, 0, 0, 0, 0, 0, 0}, /* V eff + A eff */
58};
59
60static int parse_value(const uint8_t *buf, struct vc870_info *info,
61 float *result)
62{
63 int i, intval;
64 float floatval;
65
66 /* Bytes 3-7: Main display value (5 decimal digits) */
67 if (info->is_open || info->is_ol1) {
68 sr_spew("Over limit.");
69 *result = INFINITY;
70 return SR_OK;
71 } else if (!isdigit(buf[3]) || !isdigit(buf[4]) ||
72 !isdigit(buf[5]) || !isdigit(buf[6]) || !isdigit(buf[7])) {
73 sr_dbg("Invalid digits: %02x %02x %02x %02x %02X "
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74 "(%c %c %c %c %c).",
75 buf[3], buf[4], buf[5], buf[6], buf[7],
76 buf[3], buf[4], buf[5], buf[6], buf[7]);
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77 return SR_ERR;
78 }
79
80 intval = 0;
81 for (i = 0; i < 5; i++)
82 intval = 10 * intval + (buf[i + 3] - '0'); /* Main display. */
83 // intval = 10 * intval + (buf[i + 8] - '0'); /* TODO: Aux display. */
84
85 /* Apply sign. */
86 intval *= info->is_sign1 ? -1 : 1;
87 // intval *= info->is_sign2 ? -1 : 1; /* TODO: Fahrenheit / aux display. */
88
89 floatval = (float)intval;
90
91 /* Note: The decimal point position will be parsed later. */
92
93 sr_spew("The display value is %f.", floatval);
94
95 *result = floatval;
96
97 return SR_OK;
98}
99
100static int parse_range(uint8_t b, float *floatval,
101 const struct vc870_info *info)
102{
103 int idx, mode;
104 float factor = 0;
105
106 idx = b - '0';
107
108 if (idx < 0 || idx > 7) {
109 sr_dbg("Invalid range byte / index: 0x%02x / 0x%02x.", b, idx);
110 return SR_ERR;
111 }
112
113 /* Parse range byte (depends on the measurement mode). */
114 if (info->is_voltage && info->is_dc && !info->is_milli)
115 mode = 0; /* DCV */
116 else if (info->is_voltage && info->is_ac)
117 mode = 1; /* ACV */
118 else if (info->is_voltage && info->is_dc && info->is_milli)
119 mode = 2; /* DCmV */
120 else if (info->is_temperature)
121 mode = 3; /* Temperature */
122 else if (info->is_resistance || info->is_continuity)
123 mode = 4; /* Resistance */
124 else if (info->is_continuity)
125 mode = 5; /* Continuity */
126 else if (info->is_capacitance)
127 mode = 6; /* Capacitance */
128 else if (info->is_diode)
129 mode = 7; /* Diode */
130 else if (info->is_frequency)
131 mode = 8; /* Frequency */
132 else if (info->is_loop_current)
133 mode = 9; /* Loop current */
134 else if (info->is_current && info->is_micro && info->is_dc)
135 mode = 10; /* DCµA */
136 else if (info->is_current && info->is_micro && info->is_ac)
137 mode = 11; /* ACµA */
138 else if (info->is_current && info->is_milli && info->is_dc)
139 mode = 12; /* DCmA */
140 else if (info->is_current && info->is_milli && info->is_ac)
141 mode = 13; /* ACmA */
142 else if (info->is_current && !info->is_milli && !info->is_micro && info->is_dc)
143 mode = 14; /* DCA */
144 else if (info->is_current && !info->is_milli && !info->is_micro && info->is_ac)
145 mode = 15; /* ACA */
146 else if (info->is_power_apparent_power)
147 mode = 16; /* Act+apparent power */
148 else if (info->is_power_factor_freq)
149 mode = 17; /* Power factor / freq */
150 else if (info->is_v_a_eff_value)
151 mode = 18; /* V eff + A eff */
152 else {
153 sr_dbg("Invalid mode, range byte was: 0x%02x.", b);
154 return SR_ERR;
155 }
156
157 factor = factors[mode][idx];
158
159 if (factor == 0) {
160 sr_dbg("Invalid factor for range byte: 0x%02x (mode=%d, idx=%d).", b, mode, idx);
161 return SR_ERR;
162 }
163
164 /* Apply respective factor (mode-dependent) on the value. */
165 *floatval *= factor;
166 sr_dbg("Applying factor %f, new value is %f.", factor, *floatval);
167
168 return SR_OK;
169}
170
171static void parse_flags(const uint8_t *buf, struct vc870_info *info)
172{
173 /* Bytes 0/1: Function / function select */
174 /* Note: Some of these mappings are fixed up later. */
175 switch (buf[0]) {
176 case 0x30: /* DCV / ACV */
177 info->is_voltage = TRUE;
178 info->is_dc = (buf[1] == 0x30);
179 info->is_ac = (buf[1] == 0x31);
180 break;
181 case 0x31: /* DCmV / Celsius */
182 if (buf[1] == 0x30)
183 info->is_voltage = info->is_milli = info->is_dc = TRUE;
184 else if (buf[1] == 0x31)
185 info->is_temperature = TRUE;
186 break;
187 case 0x32: /* Resistance / Short-circuit test */
188 info->is_resistance = (buf[1] == 0x30);
189 info->is_continuity = (buf[1] == 0x31);
190 break;
191 case 0x33: /* Capacitance */
192 info->is_capacitance = (buf[1] == 0x30);
193 break;
194 case 0x34: /* Diode */
195 info->is_diode = (buf[1] == 0x30);
196 break;
197 case 0x35: /* (4~20mA)% */
198 info->is_frequency = (buf[1] == 0x30);
199 info->is_loop_current = (buf[1] == 0x31);
200 break;
201 case 0x36: /* DCµA / ACµA */
202 info->is_current = info->is_micro = TRUE;
203 info->is_dc = (buf[1] == 0x30);
204 info->is_ac = (buf[1] == 0x31);
205 break;
206 case 0x37: /* DCmA / ACmA */
207 info->is_current = info->is_milli = TRUE;
208 info->is_dc = (buf[1] == 0x30);
209 info->is_ac = (buf[1] == 0x31);
210 break;
211 case 0x38: /* DCA / ACA */
212 info->is_current = TRUE;
213 info->is_dc = (buf[1] == 0x30);
214 info->is_ac = (buf[1] == 0x31);
215 break;
216 case 0x39: /* Active power + apparent power / power factor + frequency */
217 if (buf[1] == 0x30)
218 /* Active power + apparent power */
219 info->is_power_apparent_power = TRUE;
220 else if (buf[1] == 0x31)
221 /* Power factor + frequency */
222 info->is_power_factor_freq = TRUE;
223 else if (buf[1] == 0x32)
224 /* Voltage effective value + current effective value */
225 info->is_v_a_eff_value = TRUE;
226 break;
227 default:
228 sr_dbg("Invalid function bytes: %02x %02x.", buf[0], buf[1]);
229 break;
230 }
231
232 /* Byte 2: Range */
233
234 /* Byte 3-7: Main display digits */
235
236 /* Byte 8-12: Auxiliary display digits */
237
238 /* Byte 13: TODO: "Simulate strip tens digit". */
239
240 /* Byte 14: TODO: "Simulate strip the single digit". */
241
242 /* Byte 15: Status */
243 info->is_sign2 = (buf[15] & (1 << 3)) != 0;
244 info->is_sign1 = (buf[15] & (1 << 2)) != 0;
245 info->is_batt = (buf[15] & (1 << 1)) != 0; /* Bat. low */
246 info->is_ol1 = (buf[15] & (1 << 0)) != 0; /* Overflow (main display) */
247
248 /* Byte 16: Option 1 */
249 info->is_max = (buf[16] & (1 << 3)) != 0;
250 info->is_min = (buf[16] & (1 << 2)) != 0;
251 info->is_maxmin = (buf[16] & (1 << 1)) != 0;
252 info->is_rel = (buf[16] & (1 << 0)) != 0;
253
254 /* Byte 17: Option 2 */
255 info->is_ol2 = (buf[17] & (1 << 3)) != 0;
256 info->is_open = (buf[17] & (1 << 2)) != 0;
257 info->is_manu = (buf[17] & (1 << 1)) != 0; /* Manual mode */
258 info->is_hold = (buf[17] & (1 << 0)) != 0; /* Hold */
259
260 /* Byte 18: Option 3 */
261 info->is_light = (buf[18] & (1 << 3)) != 0;
262 info->is_usb = (buf[18] & (1 << 2)) != 0; /* Always on */
263 info->is_warning = (buf[18] & (1 << 1)) != 0; /* Never seen? */
264 info->is_auto_power = (buf[18] & (1 << 0)) != 0; /* Always on */
265
266 /* Byte 19: Option 4 */
267 info->is_misplug_warn = (buf[19] & (1 << 3)) != 0; /* Never gets set? */
268 info->is_lo = (buf[19] & (1 << 2)) != 0;
269 info->is_hi = (buf[19] & (1 << 1)) != 0;
270 info->is_open2 = (buf[19] & (1 << 0)) != 0; /* TODO: Unknown. */
271
272 /* Byte 20: Dual display bit */
273 info->is_dual_display = (buf[20] & (1 << 0)) != 0;
274
275 /* Byte 21: Always '\r' (carriage return, 0x0d, 13) */
276
277 /* Byte 22: Always '\n' (newline, 0x0a, 10) */
278
279 info->is_auto = !info->is_manu;
280 info->is_rms = TRUE;
281}
282
283static void handle_flags(struct sr_datafeed_analog *analog,
284 float *floatval, const struct vc870_info *info)
285{
286 /*
287 * Note: is_micro etc. are not used directly to multiply/divide
288 * floatval, this is handled via parse_range() and factors[][].
289 */
290
291 /* Measurement modes */
292 if (info->is_voltage) {
293 analog->mq = SR_MQ_VOLTAGE;
294 analog->unit = SR_UNIT_VOLT;
295 }
296 if (info->is_current) {
297 analog->mq = SR_MQ_CURRENT;
298 analog->unit = SR_UNIT_AMPERE;
299 }
300 if (info->is_resistance) {
301 analog->mq = SR_MQ_RESISTANCE;
302 analog->unit = SR_UNIT_OHM;
303 }
304 if (info->is_frequency) {
305 analog->mq = SR_MQ_FREQUENCY;
306 analog->unit = SR_UNIT_HERTZ;
307 }
308 if (info->is_capacitance) {
309 analog->mq = SR_MQ_CAPACITANCE;
310 analog->unit = SR_UNIT_FARAD;
311 }
312 if (info->is_temperature) {
313 analog->mq = SR_MQ_TEMPERATURE;
314 analog->unit = SR_UNIT_CELSIUS;
315 /* TODO: Handle Fahrenheit in auxiliary display. */
316 // analog->unit = SR_UNIT_FAHRENHEIT;
317 }
318 if (info->is_continuity) {
319 analog->mq = SR_MQ_CONTINUITY;
320 analog->unit = SR_UNIT_BOOLEAN;
321 /* Vendor docs: "< 20 Ohm acoustic" */
322 *floatval = (*floatval < 0.0 || *floatval > 20.0) ? 0.0 : 1.0;
323 }
324 if (info->is_diode) {
325 analog->mq = SR_MQ_VOLTAGE;
326 analog->unit = SR_UNIT_VOLT;
327 }
328 if (info->is_loop_current) {
329 /* 4mA = 0%, 20mA = 100% */
330 analog->mq = SR_MQ_CURRENT;
331 analog->unit = SR_UNIT_PERCENTAGE;
332 }
333 if (info->is_power) {
334 analog->mq = SR_MQ_POWER;
335 analog->unit = SR_UNIT_WATT;
336 }
337 if (info->is_power_factor_freq) {
338 /* TODO: Handle power factor. */
339 // analog->mq = SR_MQ_POWER_FACTOR;
340 // analog->unit = SR_UNIT_UNITLESS;
341 analog->mq = SR_MQ_FREQUENCY;
342 analog->unit = SR_UNIT_HERTZ;
343 }
344 if (info->is_power_apparent_power) {
345 analog->mq = SR_MQ_POWER;
346 analog->unit = SR_UNIT_WATT;
347 /* TODO: Handle apparent power. */
348 // analog->mq = SR_MQ_APPARENT_POWER;
349 // analog->unit = SR_UNIT_VOLT_AMPERE;
350 }
351
352 /* Measurement related flags */
353 if (info->is_ac)
354 analog->mqflags |= SR_MQFLAG_AC;
355 if (info->is_dc)
356 analog->mqflags |= SR_MQFLAG_DC;
357 if (info->is_auto)
358 analog->mqflags |= SR_MQFLAG_AUTORANGE;
359 if (info->is_diode)
360 analog->mqflags |= SR_MQFLAG_DIODE;
361 if (info->is_hold)
362 /*
363 * Note: HOLD only affects the number displayed on the LCD,
364 * but not the value sent via the protocol! It also does not
365 * affect the bargraph on the LCD.
366 */
367 analog->mqflags |= SR_MQFLAG_HOLD;
368 if (info->is_max)
369 analog->mqflags |= SR_MQFLAG_MAX;
370 if (info->is_min)
371 analog->mqflags |= SR_MQFLAG_MIN;
372 if (info->is_rel)
373 analog->mqflags |= SR_MQFLAG_RELATIVE;
374
375 /* Other flags */
376 if (info->is_batt)
377 sr_spew("Battery is low.");
378 if (info->is_auto_power)
379 sr_spew("Auto-Power-Off enabled.");
380}
381
382static gboolean flags_valid(const struct vc870_info *info)
383{
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384 (void)info;
385
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386 /* TODO: Implement. */
387 return TRUE;
388}
389
390SR_PRIV gboolean sr_vc870_packet_valid(const uint8_t *buf)
391{
392 struct vc870_info info;
393
394 /* Byte 21: Always '\r' (carriage return, 0x0d, 13) */
395 /* Byte 22: Always '\n' (newline, 0x0a, 10) */
396 if (buf[21] != '\r' || buf[22] != '\n')
397 return FALSE;
398
399 parse_flags(buf, &info);
400
401 return flags_valid(&info);
402}
403
404SR_PRIV int sr_vc870_parse(const uint8_t *buf, float *floatval,
405 struct sr_datafeed_analog *analog, void *info)
406{
407 int ret;
408 struct vc870_info *info_local;
409
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410 info_local = (struct vc870_info *)info;
411 memset(info_local, 0, sizeof(struct vc870_info));
412
413 if (!sr_vc870_packet_valid(buf))
414 return SR_ERR;
415
416 parse_flags(buf, info_local);
417
418 if ((ret = parse_value(buf, info_local, floatval)) != SR_OK) {
419 sr_dbg("Error parsing value: %d.", ret);
420 return ret;
421 }
422
423 if ((ret = parse_range(buf[2], floatval, info_local)) != SR_OK)
424 return ret;
425
426 handle_flags(analog, floatval, info_local);
427
428 return SR_OK;
429}