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ut71x: properly set encoding digits

This commit is contained in:
Aurelien Jacobs 2016-08-17 01:37:44 +02:00 committed by Uwe Hermann
parent 47166326ef
commit 4f414d4cbe
1 changed files with 28 additions and 30 deletions
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58
src/dmm/ut71x.c
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@ -35,28 +35,28 @@
#define LOG_PREFIX "ut71x"
/*
* Factors for the respective measurement mode (0 means "invalid").
* Exponents for the respective measurement mode.
*
* 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 const int exponents[16][8] = {
{ -5, 0, 0, 0, 0, 0, 0, 0 }, /* AC mV */
{ 0, -4, -3, -2, -1, 0, 0, 0 }, /* DC V */
{ 0, -4, -3, -2, -1, 0, 0, 0 }, /* AC V */
{ -5, 0, 0, 0, 0, 0, 0, 0 }, /* DC mV */
{ 0, -1, 0, 1, 2, 3, 4, 0 }, /* Resistance */
{ 0, -12, -11, -10, -9, -8, -7, -6 }, /* Capacitance */
{ -1, 0, 0, 0, 0, 0, 0, 0 }, /* Temp (C) */
{ -8, -7, 0, 0, 0, 0, 0, 0 }, /* uA */
{ -6, -5, 0, 0, 0, 0, 0, 0 }, /* mA */
{ 0, -3, 0, 0, 0, 0, 0, 0 }, /* 10A */
{ -1, 0, 0, 0, 0, 0, 0, 0 }, /* Continuity */
{ -4, 0, 0, 0, 0, 0, 0, 0 }, /* Diode */
{ -3, -2, -1, 0, 1, 2, 3, 4 }, /* Frequency */
{ -1, 0, 0, 0, 0, 0, 0, 0 }, /* Temp (F) */
{ 0, 0, 0, 0, 0, 0, 0, 0 }, /* Power */
{ -2, 0, 0, 0, 0, 0, 0, 0 }, /* Loop current */
};
static int parse_value(const uint8_t *buf, struct ut71x_info *info, float *result)
@ -95,10 +95,9 @@ static int parse_value(const uint8_t *buf, struct ut71x_info *info, float *resul
return SR_OK;
}
static int parse_range(const uint8_t *buf, float *floatval)
static int parse_range(const uint8_t *buf, float *floatval, int *exponent)
{
int idx, mode;
float factor = 0;
idx = buf[5] - '0';
if (idx < 0 || idx > 7) {
@ -114,15 +113,11 @@ static int parse_range(const uint8_t *buf, float *floatval)
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;
}
*exponent = exponents[mode][idx];
/* Apply respective factor (mode-dependent) on the value. */
*floatval *= factor;
sr_dbg("Applying factor %f, new value is %f.", factor, *floatval);
/* 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;
}
@ -327,7 +322,7 @@ SR_PRIV gboolean sr_ut71x_packet_valid(const uint8_t *buf)
SR_PRIV int sr_ut71x_parse(const uint8_t *buf, float *floatval,
struct sr_datafeed_analog *analog, void *info)
{
int ret;
int ret, exponent = 0;
struct ut71x_info *info_local;
info_local = (struct ut71x_info *)info;
@ -343,10 +338,13 @@ SR_PRIV int sr_ut71x_parse(const uint8_t *buf, float *floatval,
return ret;
}
if ((ret = parse_range(buf, floatval)) != SR_OK)
if ((ret = parse_range(buf, floatval, &exponent)) != SR_OK)
return ret;
handle_flags(analog, floatval, info);
analog->encoding->digits = -exponent;
analog->spec->spec_digits = -exponent;
return SR_OK;
}