feat(bsec): add option to set a static temperature offset

Documentation/card10-cfg.rst

@@ -60,4 +60,6 @@ Option name        Type       Description
 ``bsec_enable``    Boolean    Activate the Bosch :ref:`BSEC` binary blob to compute an Indoor Air Quality indication.
 ------------------ ---------- -----------
 ``bsec_debug``     Boolean    Turn on debug output of the BSEC system. Prints each meaurement on the console.
+------------------ ---------- -----------
+``bsec_offset``    Integer    Temperature offset in .1 K. Example: Set to `-14` if temperature reads 1.4 "C" to high.
 ================== ========== ===========

epicardium/modules/bsec.c

@@ -363,8 +363,6 @@ int bsec_activate(void)
 	float sample_rate = BSEC_SAMPLE_RATE_LP;
 #endif
 
-	float temperature_offset = 0.0;
-
 	bool bsec_enabled =
 		config_get_boolean_with_default("bsec_enabled", false);
 	if (!bsec_enabled) {
@@ -372,10 +370,18 @@ int bsec_activate(void)
 	}
 
 	debug = config_get_boolean_with_default("bsec_debug", false);
+
+	float temperature_offset =
+		config_get_integer_with_default("bsec_offset", 0) / 10.;
+	if (temperature_offset != 0.0) {
+		printf("BSEC Temp offset %d/10 K\n",
+		       (int)(temperature_offset * 10));
+	}
+
 	/* Puts AT LEAST 2 * #BSEC_MAX_PROPERTY_BLOB_SIZE = 2 * 454 = 908 bytes onto the stack */
 	ret = bsec_iot_init(
 		sample_rate,
-		temperature_offset,
+		-temperature_offset,
 		i2c_write,
 		i2c_read,
 		delay,