X-Git-Url: https://sigrok.org/gitweb/?p=libsigrok.git;a=blobdiff_plain;f=src%2Fanalog.c;h=4ec724cfde488a0ae4a37a5c2ab0f0b414264da8;hp=4eda290f1197f162f03e3e54b64330f1f1f3a5d0;hb=f37f11ec6b3b0bc15de0a186dd9ba424635c117e;hpb=5e5fde6e2c3aabfc61bcd35a53ab0d401b2176ba

diff --git a/src/analog.c b/src/analog.c
index 4eda290f..4ec724cf 100644
--- a/src/analog.c
+++ b/src/analog.c
@@ -88,6 +88,9 @@ static struct unit_mq_string unit_strings[] = {
 	{ SR_UNIT_MOMME, "momme" },
 	{ SR_UNIT_TOLA, "tola" },
 	{ SR_UNIT_PIECE, "pcs" },
+	{ SR_UNIT_JOULE, "J" },
+	{ SR_UNIT_COULOMB, "C" },
+	{ SR_UNIT_AMPERE_HOUR, "Ah" },
 	ALL_ZERO
 };
 
@@ -176,6 +179,9 @@ SR_API int sr_analog_to_float(const struct sr_datafeed_analog *analog,
 {
 	unsigned int b, count;
 	gboolean bigendian;
+	uint8_t conv_buf[sizeof(double)];
+	float *conv_f = (float*)conv_buf;
+	double *conv_d = (double*)conv_buf;
 
 	if (!analog || !(analog->data) || !(analog->meaning)
 			|| !(analog->encoding) || !outbuf)
@@ -274,20 +280,39 @@ SR_API int sr_analog_to_float(const struct sr_datafeed_analog *analog,
 		/* The data is already in the right format. */
 		memcpy(outbuf, analog->data, count * sizeof(float));
 	} else {
-		for (unsigned int i = 0; i < count; i += analog->encoding->unitsize) {
+		for (unsigned int i = 0; i < count; i++) {
 			for (b = 0; b < analog->encoding->unitsize; b++) {
 				if (analog->encoding->is_bigendian == bigendian)
-					((uint8_t *)outbuf)[i + b] =
+					conv_buf[b] =
 						((uint8_t *)analog->data)[i * analog->encoding->unitsize + b];
 				else
-					((uint8_t *)outbuf)[i + (analog->encoding->unitsize - b)] =
+					conv_buf[analog->encoding->unitsize - b - 1] =
 						((uint8_t *)analog->data)[i * analog->encoding->unitsize + b];
 			}
-			if (analog->encoding->scale.p != 1
-					|| analog->encoding->scale.q != 1)
-				outbuf[i] = (outbuf[i] * analog->encoding->scale.p) / analog->encoding->scale.q;
-			float offset = ((float)analog->encoding->offset.p / (float)analog->encoding->offset.q);
-			outbuf[i] += offset;
+
+			if (analog->encoding->unitsize == sizeof(float)) {
+				if (analog->encoding->scale.p != 1
+				    || analog->encoding->scale.q != 1)
+					*conv_f = (*conv_f * analog->encoding->scale.p) / analog->encoding->scale.q;
+				float offset = ((float)analog->encoding->offset.p / (float)analog->encoding->offset.q);
+				*conv_f += offset;
+
+				outbuf[i] = *conv_f;
+			}
+			else if (analog->encoding->unitsize == sizeof(double)) {
+				if (analog->encoding->scale.p != 1
+				    || analog->encoding->scale.q != 1)
+					*conv_d = (*conv_d * analog->encoding->scale.p) / analog->encoding->scale.q;
+				double offset = ((double)analog->encoding->offset.p / (double)analog->encoding->offset.q);
+				*conv_d += offset;
+
+				outbuf[i] = *conv_d;
+			}
+			else {
+				sr_err("Unsupported floating-point unit size '%d' for analog-to-float"
+				       " conversion.", analog->encoding->unitsize);
+				return SR_ERR;
+			}
 		}
 	}
 
@@ -602,9 +627,8 @@ SR_API int sr_rational_mult(struct sr_rational *res, const struct sr_rational *a
  * @param[out] res Result.
  *
  * @retval SR_OK Success.
- * @retval SR_ERR_ARG Division by zero.
- * @retval SR_ERR_ARG Denominator of divisor too large.
- * @retval SR_ERR_ARG Resulting value too large.
+ * @retval SR_ERR_ARG Division by zero, denominator of divisor too large,
+ *                    or resulting value too large.
  *
  * @since 0.5.0
  */