license: remove FSF postal address from boiler plate license text

[libsigrok.git] / src / dmm / ut372.c

diff --git a/src/dmm/ut372.c b/src/dmm/ut372.c
index b5e2c703f7682eaf132888aa4fb70362951d089f..271d034c3bbc3c3de899d23dace1b0fa5131f707 100644 (file)
--- a/src/dmm/ut372.c
+++ b/src/dmm/ut372.c
@@ -14,22 +14,23 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
 /*
  * UNI-T UT372 protocol parser.
  */
 
+#include <config.h>
 #include <stdlib.h>
+#include <stdint.h>
 #include <math.h>
-#include "libsigrok.h"
+#include <libsigrok/libsigrok.h>
 #include "libsigrok-internal.h"
 
 #define LOG_PREFIX "ut372"
 
-char lookup[] = {
+static const uint8_t lookup[] = {
        0x7B,
        0x60,
        0x5E,
@@ -39,35 +40,86 @@ char lookup[] = {
        0x3F,
        0x70,
        0x7F,
-       0x7D
+       0x7D,
 };
 
 #define DECIMAL_POINT_MASK 0x80
 
+#define FLAGS1_HOLD_MASK (1 << 2)
+
+#define FLAGS2_RPM_MASK (1 << 0)
+#define FLAGS2_COUNT_MASK (1 << 1)
+#define FLAGS2_MAX_MASK (1 << 4)
+#define FLAGS2_MIN_MASK (1 << 5)
+#define FLAGS2_AVG_MASK (1 << 6)
+
+/* Decode a pair of characters into a byte. */
+static uint8_t decode_pair(const uint8_t *buf)
+{
+       unsigned int i;
+       char hex[3];
+
+       hex[2] = '\0';
+
+       for (i = 0; i < 2; i++) {
+               hex[i] = buf[i];
+               if (hex[i] > 0x39)
+                       hex[i] += 7;
+       }
+
+       return strtol(hex, NULL, 16);
+}
+
 SR_PRIV gboolean sr_ut372_packet_valid(const uint8_t *buf)
 {
-       return (buf[25] == '\r' && buf[26] == '\n');
+       uint8_t flags2;
+
+       if (!(buf[25] == '\r' && buf[26] == '\n'))
+               return FALSE;
+
+       flags2 = decode_pair(buf + 23);
+
+       if (!(flags2 & (FLAGS2_RPM_MASK | FLAGS2_COUNT_MASK)))
+               /* Device is in the setup menu - no valid data shown. */
+               return FALSE;
+
+       return TRUE;
 }
 
 SR_PRIV int sr_ut372_parse(const uint8_t *buf, float *floatval,
                struct sr_datafeed_analog *analog, void *info)
 {
-       unsigned int i, j, segments, value, divisor;
-       char hex[3];
+       unsigned int i, j, value;
+       uint8_t segments, flags1, flags2;
+       int exponent;
 
        (void) info;
 
-       hex[2] = '\0';
+       flags1 = decode_pair(buf + 21);
+       flags2 = decode_pair(buf + 23);
+
+       if (flags2 & FLAGS2_RPM_MASK) {
+               analog->meaning->mq = SR_MQ_FREQUENCY;
+               analog->meaning->unit = SR_UNIT_REVOLUTIONS_PER_MINUTE;
+       } else if (flags2 & FLAGS2_COUNT_MASK) {
+               analog->meaning->mq = SR_MQ_COUNT;
+               analog->meaning->unit = SR_UNIT_UNITLESS;
+       }
+
+       if (flags1 & FLAGS1_HOLD_MASK)
+               analog->meaning->mqflags |= SR_MQFLAG_HOLD;
+       if (flags2 & FLAGS2_MIN_MASK)
+               analog->meaning->mqflags |= SR_MQFLAG_MIN;
+       if (flags2 & FLAGS2_MAX_MASK)
+               analog->meaning->mqflags |= SR_MQFLAG_MAX;
+       if (flags2 & FLAGS2_AVG_MASK)
+               analog->meaning->mqflags |= SR_MQFLAG_AVG;
+
        value = 0;
-       divisor = 1;
+       exponent = 0;
 
        for (i = 0; i < 5; i++) {
-               for (j = 0; j < 2; j++) {
-                       hex[j] = buf[2*i + 1 + j];
-                       if (hex[j] > 0x39)
-                               hex[j] += 7;
-               }
-               segments = strtol(hex, NULL, 16);
+               segments = decode_pair(buf + 1 + (2 * i));
                for (j = 0; j < ARRAY_SIZE(lookup); j++) {
                        if (lookup[j] == (segments & ~DECIMAL_POINT_MASK)) {
                                value += j * pow(10, i);
@@ -75,13 +127,13 @@ SR_PRIV int sr_ut372_parse(const uint8_t *buf, float *floatval,
                        }
                }
                if (segments & DECIMAL_POINT_MASK)
-                       divisor = pow(10, i);
+                       exponent = -i;
        }
 
-       *floatval = (float) value / divisor;
+       *floatval = (float) value * powf(10, exponent);
 
-       analog->mq = SR_MQ_FREQUENCY;
-       analog->unit = SR_UNIT_REVOLUTIONS_PER_MINUTE;
+       analog->encoding->digits  = -exponent;
+       analog->spec->spec_digits = -exponent;
 
        return SR_OK;
 }