aylp_units helper functions and pid units param

devices/pid.c

@@ -36,6 +36,10 @@ int pid_init(struct aylp_device *self)
 				data->type = AYLP_T_MATRIX;
 			else log_error("Unrecognized type: %s", s);
 			log_trace("type = %s (0x%hhX)", s, data->type);
+		} else if (!strcmp(key, "units")) {
+			const char *s = json_object_get_string(val);
+			data->units = aylp_units_from_string(s);
+			log_trace("units = %s (0x%hhX)", s, data->units);
 		} else if (!strcmp(key, "p")) {
 			data->p = json_object_get_double(val);
 			log_trace("p = %G", data->p);
@@ -85,7 +89,7 @@ int pid_init(struct aylp_device *self)
 	self->type_in = data->type;
 	self->units_in = AYLP_U_ANY;
 	self->type_out = 0;
-	self->units_out = 0;
+	self->units_out = data->units;
 	return 0;
 }
 

devices/pid.h

@@ -7,6 +7,8 @@
 struct aylp_pid_data {
 	// param type in ["vector", "matrix"]
 	aylp_type type;
+	// units to output
+	aylp_units units;
 	// accumulated error
 	union {
 		gsl_vector *acc_v;

doc/devices/pid.md

@@ -26,6 +26,8 @@ Parameters
 - `type` (string) (required)
   - "vector" if we are expecting `T_VECTOR` input, and "matrix" if we are
     expecting `T_MATRIX` input.
+- `units` (string) (optional)
+  - Output units, e.g. "V", "rad", etc. Defaults to null (unchanged from input).
 - `p` (float) (optional)
   - Coefficent for proportional correction (see equation above). Defaults
     to 1.0.

libaylp/anyloop.c

@@ -51,12 +51,9 @@ static void cleanup(void)
 
 aylp_type aylp_type_from_string(const char *type_name)
 {
-	if (!strcasecmp(type_name, "none")) return AYLP_T_NONE;
-	if (!strcasecmp(type_name, "block")) return AYLP_T_BLOCK;
-	if (!strcasecmp(type_name, "vector")) return AYLP_T_VECTOR;
-	if (!strcasecmp(type_name, "matrix")) return AYLP_T_MATRIX;
-	if (!strcasecmp(type_name, "block_uchar")) return  AYLP_T_BLOCK_UCHAR;
-	if (!strcasecmp(type_name, "matrix_uchar")) return AYLP_T_MATRIX_UCHAR;
+	#define AYLP_TYPE_FROM_STRING_MATCH_TYPE(TYPE, type) \
+	if (!strcasecmp(type_name, #type)) return TYPE;
+	FOR_AYLP_TYPES(AYLP_TYPE_FROM_STRING_MATCH_TYPE)
 
 	log_error("Couldn't parse type: %s", type_name);
 	return AYLP_T_NONE;
@@ -65,22 +62,40 @@ aylp_type aylp_type_from_string(const char *type_name)
 const char *aylp_type_to_string(aylp_type type)
 {
 	switch (type) {
-	case AYLP_T_BLOCK:
-		return "block";
-	case AYLP_T_VECTOR:
-		return "vector";
-	case AYLP_T_MATRIX:
-		return "matrix";
-	case AYLP_T_BLOCK_UCHAR:
-		return "block_uchar";
-	case AYLP_T_MATRIX_UCHAR:
-		return "matrix_uchar";
+	#define AYLP_TYPE_TO_STRING_MATCH_TYPE(TYPE, type) \
+	case TYPE: \
+		return #type; \
+		break;
+	FOR_AYLP_TYPES(AYLP_TYPE_TO_STRING_MATCH_TYPE)
 	default:
 		log_error("Unknown type 0x%hhX", type);
 		return "NONE";
 	}
 }
 
+aylp_units aylp_units_from_string(const char *units_name)
+{
+	#define AYLP_UNITS_FROM_STRING_MATCH_UNITS(UNITS, units) \
+	if (!strcasecmp(units_name, #units)) return UNITS;
+	FOR_AYLP_UNITS(AYLP_UNITS_FROM_STRING_MATCH_UNITS)
+
+	log_error("Couldn't parse units: %s", units_name);
+	return AYLP_U_NONE;
+}
+
+const char *aylp_units_to_string(aylp_units units)
+{
+	switch (units) {
+	#define AYLP_UNITS_TO_STRING_MATCH_UNITS(UNITS, units) \
+	case UNITS: \
+		return #units; \
+		break;
+	FOR_AYLP_UNITS(AYLP_UNITS_TO_STRING_MATCH_UNITS)
+	default:
+		log_error("Unknown units 0x%hhX", units);
+		return "NONE";
+	}
+}
 
 
 static void handle_signal(int sig, siginfo_t *info, void *context)

libaylp/anyloop.h

@@ -75,6 +75,15 @@ enum {
 	AYLP_T_ANY	= 0xFF,
 	// add more as necessary
 };
+// https://en.wikipedia.org/wiki/X_macro
+#define FOR_AYLP_TYPES(DO) \
+	DO(AYLP_T_NONE, none) \
+	DO(AYLP_T_BLOCK, block) \
+	DO(AYLP_T_VECTOR, vector) \
+	DO(AYLP_T_MATRIX, matrix) \
+	DO(AYLP_T_BLOCK_UCHAR, block_uchar) \
+	DO(AYLP_T_MATRIX_UCHAR, matrix_uchar) \
+	DO(AYLP_T_ANY, any)
 
 
 /** Enum for units of data in aylp_state.
@@ -99,6 +108,13 @@ enum {
 	AYLP_U_ANY	= 0xFF,
 	// add more as necessary
 };
+#define FOR_AYLP_UNITS(DO) \
+	DO(AYLP_U_NONE, none) \
+	DO(AYLP_U_COUNTS, counts) \
+	DO(AYLP_U_MINMAX, minmax) \
+	DO(AYLP_U_RAD, rad) \
+	DO(AYLP_U_V, V) \
+	DO(AYLP_U_ANY, any)
 
 
 /** Little-endian representation of "AYLP" as a magic number. */
@@ -233,17 +249,29 @@ struct aylp_conf {
 };
 
 
-/** Convert a string to a type.
- * @param type_name: the string holding the type name (e.g. "vector")
+/** Convert a string to a pure type. Case insensitive.
+ * @param type_name: the string holding the type name (e.g. "vector").
  */
 aylp_type aylp_type_from_string(const char *type_name);
 
 
-/** Convert a type to its name as a string.
- * @param type: the string holding the type name (e.g. "vector")
+/** Convert a pure type to its name as a string. Returns lowercase.
+ * @param type: the type to convert (e.g. AYLP_T_VECTOR).
  */
 const char *aylp_type_to_string(aylp_type type);
 
 
+/** Convert a string to the pure units it represents. Case insensitive.
+ * @param units_name: the string holding the units (e.g. "rad").
+ */
+aylp_units aylp_units_from_string(const char *units_name);
+
+
+/** Convert pure units to their name as a string. Mixed case (e.g. rad, V).
+ * @param units: the units to convert (e.g. AYLP_U_RAD).
+ */
+const char *aylp_units_to_string(aylp_units units);
+
+
 #endif	// include guard