metex14: Support DMMs with slightly different protocol.

This adds support for DMMs with 5 digits in the protocol (instead of 4)
and some more whitespace variants.

diff --git a/hardware/common/dmm/metex14.c b/hardware/common/dmm/metex14.c
index 2ef5ecff7459d4f637964c0b794006fd123a13fb..f54188210f64d06a8243f86515934c61e389c0da 100644 (file)
--- a/hardware/common/dmm/metex14.c
+++ b/hardware/common/dmm/metex14.c
@@ -45,72 +45,32 @@
 
 static int parse_value(const uint8_t *buf, float *result)
 {
-       int i, sign, intval = 0, factor, decimal_point = 0, is_ol;
-       float floatval;
-       uint8_t digit;
-
-       /* Byte 3: Sign (' ' or '-') */
-       if (buf[3] == ' ') {
-               sign = 1;
-       } else if (buf[3] == '-') {
-               sign = -1;
-       } else {
-               sr_err("Invalid sign byte: 0x%02x.", buf[3]);
-               return SR_ERR;
+       int i, is_ol, cnt;
+       char valstr[7 + 1];
+
+       /* Strip all spaces from bytes 2-8. */
+       memset(&valstr, 0, 7 + 1);
+       for (i = 0, cnt = 0; i < 7; i++) {
+               if (buf[2 + i] != ' ')
+                       valstr[cnt++] = buf[2 + i];
        }
 
        /* Bytes 5-7: Over limit (various forms) */
        is_ol = 0;
-       is_ol += (!strncmp((char *)&buf[5], ".OL", 3)) ? 1 : 0;
-       is_ol += (!strncmp((char *)&buf[5], "O.L", 3)) ? 1 : 0;
-       is_ol += (!strncmp((char *)&buf[5], "OL.", 3)) ? 1 : 0;
-       is_ol += (!strncmp((char *)&buf[5], " OL", 3)) ? 1 : 0;
+       is_ol += (!strcmp((const char *)&valstr, ".OL")) ? 1 : 0;
+       is_ol += (!strcmp((const char *)&valstr, "O.L")) ? 1 : 0;
+       is_ol += (!strcmp((const char *)&valstr, "OL.")) ? 1 : 0;
+       is_ol += (!strcmp((const char *)&valstr, "OL")) ? 1 : 0;
        if (is_ol != 0) {
                sr_spew("Over limit.");
                *result = INFINITY;
                return SR_OK;
        }
 
-       /* Bytes 4-8: Value (up to 4 digits) and decimal point */
-       factor = 1000;
-       for (i = 0; i < 5; i++) {
-               digit = buf[4 + i];
-               /* Convert spaces to '0', so that we can parse them. */
-               if (digit == ' ')
-                       digit = '0';
-               if (digit == '.') {
-                       decimal_point = i;
-               } else if (isdigit(digit)) {
-                       intval += (digit - '0') * factor;
-                       factor /= 10;
-               } else {
-                       sr_err("Invalid digit byte: 0x%02x.", digit);
-                       return SR_ERR;
-               }
-       }
-
-       floatval = (float)intval;
-
-       /* Decimal point position */
-       if (decimal_point == 0 || decimal_point == 4) {
-               /* TODO: Doesn't happen? */
-       } else if (decimal_point == 1) {
-               floatval /= 1000;
-       } else if (decimal_point == 2) {
-               floatval /= 100;
-       } else if (decimal_point == 3) {
-               floatval /= 10;
-       } else {
-               sr_err("Invalid decimal point position: %d.", decimal_point);
-               return SR_ERR;
-       }
-
-       /* Apply sign. */
-       floatval *= sign;
-
-       sr_spew("The display value is %f.", floatval);
+       /* Bytes 2-8: Sign, value (up to 5 digits) and decimal point */
+       sscanf((const char *)&valstr, "%f", result);
 
-       *result = floatval;
+       sr_spew("The display value is %f.", *result);
 
        return SR_OK;
 }
@@ -141,16 +101,16 @@ static void parse_flags(const char *buf, struct metex14_info *info)
        if (info->is_dc || info->is_ac)
                info->is_volt = TRUE;
 
-       /* Byte 2: Always space (0x20). */
+       /* Bytes 2-8: See parse_value(). */
 
-       /* Bytes 3-8: See parse_value(). */
-
-       /* Bytes 9-12: Unit */
+       /* Strip all spaces from bytes 9-12. */
        memset(&unit, 0, 4 + 1);
        for (i = 0, cnt = 0; i < 4; i++) {
                if (buf[9 + i] != ' ')
                        unit[cnt++] = buf[9 + i];
        }
+
+       /* Bytes 9-12: Unit */
        u = (const char *)&unit;
        if (!strcmp(u, "A"))
                info->is_ampere = TRUE;