vc870: properly set encoding digits

diff --git a/src/dmm/vc870.c b/src/dmm/vc870.c
index dea94a2d434f125b7f594d78fb4fb877dcd5eebf..43be935e3bdebaff92777a04f550607784e3d936 100644 (file)
--- a/src/dmm/vc870.c
+++ b/src/dmm/vc870.c
@@ -28,39 +28,39 @@
 
 #define LOG_PREFIX "vc870"
 
-/* Factors for the respective measurement mode (0 means "invalid"). */
-static const float factors[][8] = {
-       {1e-4,  1e-3,  1e-2,  1e-1, 0,    0,    0,    0},    /* DCV */
-       {1e-3,  1e-2,  1e-1,  1,    0,    0,    0,    0},    /* ACV */
-       {1e-5,  0,     0,     0,    0,    0,    0,    0},    /* DCmV */
-       {1e-1,  0,     0,     0,    0,    0,    0,    0},    /* Temperature (C) */
-//     {1e-2,  0,     0,     0,    0,    0,    0,    0},    /* TODO: Temperature (F) */
+/* 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 1e-1 -> 1e1 for the resistance
+        * Note: The sequence -1 -> 1 for the resistance
         * value is correct and verified in practice!
         * Don't trust the vendor docs on this.
         */
-       {1e-2,  1e-1,  1e1,   1e2,  1e3,  1e4,  0,    0},    /* Resistance */
-       {1e-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 */
-       {1e-4,  0,     0,     0,    0,    0,    0,    0},    /* Diode */
-       {1e-3,  1e-2,  1e-1,  1,    1e1,  1e2,  1e3,  1e4},  /* Frequency */
-       {1e-2,  0,     0,     0,    0,    0,    0,    0},    /* Loop current */
+       {  -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 factors used, although docs say they should
+        * in the exponents used, although docs say they should
         * be the same.
         */
-       {1e-8,  1e-7,  0,     0,    0,    0,    0,    0},    /* DCµA */
-       {1e-7,  1e-6,  0,     0,    0,    0,    0,    0},    /* ACµA */
-       {1e-6,  1e-5,  0,     0,    0,    0,    0,    0},    /* DCmA */
-       {1e-5,  1e-4,  0,     0,    0,    0,    0,    0},    /* ACmA */
-       {1e-3,  0,     0,     0,    0,    0,    0,    0},    /* DCA */
-       /* TODO: Verify factor for ACA */
-       {1e-3,  0,     0,     0,    0,    0,    0,    0},    /* ACA */
-       {1e-1,  0,     0,     0,    0,    0,    0,    0},    /* Act+apparent power */
-       {1e-3,  0,     0,     0,    0,    0,    0,    0},    /* Power factor / freq */
-       {1e-1,  0,     0,     0,    0,    0,    0,    0},    /* V eff + A eff */
+       {  -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,
@@ -100,11 +100,10 @@ static int parse_value(const uint8_t *buf, struct vc870_info *info,
        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)
 {
        int idx, mode;
-       float factor = 0;
 
        idx = b - '0';
 
@@ -157,16 +156,11 @@ static int parse_range(uint8_t b, float *floatval,
                return SR_ERR;
        }
 
-       factor = factors[mode][idx];
+       *exponent = exponents[mode][idx];
 
-       if (factor == 0) {
-               sr_dbg("Invalid factor for range byte: 0x%02x (mode=%d, idx=%d).", b, mode, idx);
-               return SR_ERR;
-       }
-
-       /* 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;
 }
@@ -287,7 +281,7 @@ static void handle_flags(struct sr_datafeed_analog *analog,
 {
        /*
         * 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 */
@@ -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,
                           struct sr_datafeed_analog *analog, void *info)
 {
-       int ret;
+       int ret, exponent = 0;
        struct vc870_info *info_local;
 
        info_local = (struct vc870_info *)info;
@@ -430,10 +424,13 @@ SR_PRIV int sr_vc870_parse(const uint8_t *buf, float *floatval,
                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;
 
        handle_flags(analog, floatval, info_local);
 
+       analog->encoding->digits  = -exponent;
+       analog->spec->spec_digits = -exponent;
+
        return SR_OK;
 }