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vc870: properly set encoding digits

This commit is contained in:
Aurelien Jacobs 2016-08-17 01:40:11 +02:00 committed by Uwe Hermann
parent 4f414d4cbe
commit a66d44bee1
1 changed files with 36 additions and 39 deletions
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75
src/dmm/vc870.c
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@ -28,39 +28,39 @@
#define LOG_PREFIX "vc870" #define LOG_PREFIX "vc870"
/* Factors for the respective measurement mode (0 means "invalid"). */ /* Exponents for the respective measurement mode. */
static const float factors[][8] = { static const int exponents[][8] = {
{1e-4, 1e-3, 1e-2, 1e-1, 0, 0, 0, 0}, /* DCV */ { -4, -3, -2, -1, 0, 0, 0, 0 }, /* DCV */
{1e-3, 1e-2, 1e-1, 1, 0, 0, 0, 0}, /* ACV */ { -3, -2, -1, 0, 0, 0, 0, 0 }, /* ACV */
{1e-5, 0, 0, 0, 0, 0, 0, 0}, /* DCmV */ { -5, 0, 0, 0, 0, 0, 0, 0 }, /* DCmV */
{1e-1, 0, 0, 0, 0, 0, 0, 0}, /* Temperature (C) */ { -1, 0, 0, 0, 0, 0, 0, 0 }, /* Temperature (C) */
// {1e-2, 0, 0, 0, 0, 0, 0, 0}, /* TODO: Temperature (F) */ // { -2, 0, 0, 0, 0, 0, 0, 0 }, /* TODO: Temperature (F) */
/* /*
* Note: The sequence 1e-1 -> 1e1 for the resistance * Note: The sequence -1 -> 1 for the resistance
* value is correct and verified in practice! * value is correct and verified in practice!
* Don't trust the vendor docs on this. * Don't trust the vendor docs on this.
*/ */
{1e-2, 1e-1, 1e1, 1e2, 1e3, 1e4, 0, 0}, /* Resistance */ { -2, -1, 1, 2, 3, 4, 0, 0 }, /* Resistance */
{1e-2, 0, 0, 0, 0, 0, 0, 0}, /* Continuity */ { -2, 0, 0, 0, 0, 0, 0, 0 }, /* Continuity */
{1e-12, 1e-11, 1e-10, 1e-9, 1e-8, 1e-7, 1e-6, 0}, /* Capacitance */ { -12, -11, -10, -9, -8, -7, -6, 0 }, /* Capacitance */
{1e-4, 0, 0, 0, 0, 0, 0, 0}, /* Diode */ { -4, 0, 0, 0, 0, 0, 0, 0 }, /* Diode */
{1e-3, 1e-2, 1e-1, 1, 1e1, 1e2, 1e3, 1e4}, /* Frequency */ { -3, -2, -1, 0, 1, 2, 3, 4 }, /* Frequency */
{1e-2, 0, 0, 0, 0, 0, 0, 0}, /* Loop current */ { -2, 0, 0, 0, 0, 0, 0, 0 }, /* Loop current */
/* /*
* Note: Measurements showed that AC and DC differ * Note: Measurements showed that AC and DC differ
* in the factors used, although docs say they should * in the exponents used, although docs say they should
* be the same. * be the same.
*/ */
{1e-8, 1e-7, 0, 0, 0, 0, 0, 0}, /* DCµA */ { -8, -7, 0, 0, 0, 0, 0, 0 }, /* DCµA */
{1e-7, 1e-6, 0, 0, 0, 0, 0, 0}, /* ACµA */ { -7, -6, 0, 0, 0, 0, 0, 0 }, /* ACµA */
{1e-6, 1e-5, 0, 0, 0, 0, 0, 0}, /* DCmA */ { -6, -5, 0, 0, 0, 0, 0, 0 }, /* DCmA */
{1e-5, 1e-4, 0, 0, 0, 0, 0, 0}, /* ACmA */ { -5, -4, 0, 0, 0, 0, 0, 0 }, /* ACmA */
{1e-3, 0, 0, 0, 0, 0, 0, 0}, /* DCA */ { -3, 0, 0, 0, 0, 0, 0, 0 }, /* DCA */
/* TODO: Verify factor for ACA */ /* TODO: Verify exponent for ACA */
{1e-3, 0, 0, 0, 0, 0, 0, 0}, /* ACA */ { -3, 0, 0, 0, 0, 0, 0, 0 }, /* ACA */
{1e-1, 0, 0, 0, 0, 0, 0, 0}, /* Act+apparent power */ { -1, 0, 0, 0, 0, 0, 0, 0 }, /* Act+apparent power */
{1e-3, 0, 0, 0, 0, 0, 0, 0}, /* Power factor / freq */ { -3, 0, 0, 0, 0, 0, 0, 0 }, /* Power exponent / freq */
{1e-1, 0, 0, 0, 0, 0, 0, 0}, /* V eff + A eff */ { -1, 0, 0, 0, 0, 0, 0, 0 }, /* V eff + A eff */
}; };
static int parse_value(const uint8_t *buf, struct vc870_info *info, static int parse_value(const uint8_t *buf, struct vc870_info *info,
@ -100,11 +100,10 @@ static int parse_value(const uint8_t *buf, struct vc870_info *info,
return SR_OK; return SR_OK;
} }
static int parse_range(uint8_t b, float *floatval, static int parse_range(uint8_t b, float *floatval, int *exponent,
const struct vc870_info *info) const struct vc870_info *info)
{ {
int idx, mode; int idx, mode;
float factor = 0;
idx = b - '0'; idx = b - '0';
@ -157,16 +156,11 @@ static int parse_range(uint8_t b, float *floatval,
return SR_ERR; return SR_ERR;
} }
factor = factors[mode][idx]; *exponent = exponents[mode][idx];
if (factor == 0) { /* Apply respective exponent (mode-dependent) on the value. */
sr_dbg("Invalid factor for range byte: 0x%02x (mode=%d, idx=%d).", b, mode, idx); *floatval *= powf(10, *exponent);
return SR_ERR; sr_dbg("Applying exponent %d, new value is %f.", *exponent, *floatval);
}
/* Apply respective factor (mode-dependent) on the value. */
*floatval *= factor;
sr_dbg("Applying factor %f, new value is %f.", factor, *floatval);
return SR_OK; return SR_OK;
} }
@ -287,7 +281,7 @@ static void handle_flags(struct sr_datafeed_analog *analog,
{ {
/* /*
* Note: is_micro etc. are not used directly to multiply/divide * Note: is_micro etc. are not used directly to multiply/divide
* floatval, this is handled via parse_range() and factors[][]. * floatval, this is handled via parse_range() and exponents[][].
*/ */
/* Measurement modes */ /* Measurement modes */
@ -414,7 +408,7 @@ SR_PRIV gboolean sr_vc870_packet_valid(const uint8_t *buf)
SR_PRIV int sr_vc870_parse(const uint8_t *buf, float *floatval, SR_PRIV int sr_vc870_parse(const uint8_t *buf, float *floatval,
struct sr_datafeed_analog *analog, void *info) struct sr_datafeed_analog *analog, void *info)
{ {
int ret; int ret, exponent = 0;
struct vc870_info *info_local; struct vc870_info *info_local;
info_local = (struct vc870_info *)info; info_local = (struct vc870_info *)info;
@ -430,10 +424,13 @@ SR_PRIV int sr_vc870_parse(const uint8_t *buf, float *floatval,
return ret; return ret;
} }
if ((ret = parse_range(buf[2], floatval, info_local)) != SR_OK) if ((ret = parse_range(buf[2], floatval, &exponent, info_local)) != SR_OK)
return ret; return ret;
handle_flags(analog, floatval, info_local); handle_flags(analog, floatval, info_local);
analog->encoding->digits = -exponent;
analog->spec->spec_digits = -exponent;
return SR_OK; return SR_OK;
} }