added bh1750 sensor support with adaptation to the changed driver

Author: Mircho

src/mgos_homeassistant.c

@@ -21,6 +21,7 @@
 #include "mgos_homeassistant_barometer.h"
 #include "mgos_homeassistant_gpio.h"
 #include "mgos_homeassistant_si7021.h"
+#include "mgos_homeassistant_bh1750.h"
 #include "mgos_mqtt.h"
 
 static struct mgos_homeassistant *s_homeassistant = NULL;
@@ -126,6 +127,19 @@ bool mgos_homeassistant_fromjson(struct mgos_homeassistant *ha, const char *json
 #endif
   }
 
+  while ((h = json_next_elem(json, strlen(json), h, ".provider.bh1750", &idx, &val)) != NULL) {
+#ifdef MGOS_HAVE_BH1750
+    if (!mgos_homeassistant_bh1750_fromjson(ha, val)) {
+      LOG(LL_WARN, ("Failed to add object from provider bh1750, index %d, json "
+                    "follows:%.*s",
+                    idx, (int) val.len, val.ptr));
+    }
+#else
+    LOG(LL_ERROR, ("provider.bh1750 config found: Add bh1750-i2c to mos.yml, "
+                   "skipping .. "));
+#endif
+  }
+
   while ((h = json_next_elem(json, strlen(json), h, ".provider.barometer", &idx, &val)) != NULL) {
 #ifdef MGOS_HAVE_BAROMETER
     if (!mgos_homeassistant_barometer_fromjson(ha, val)) {

src/mgos_homeassistant_bh1750.c

@@ -0,0 +1,106 @@
+/*
+ * Copyright 2020 Mircho Mirev <[email protected]>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+#ifdef MGOS_HAVE_BH1750
+#include <math.h>
+#include "mgos.h"
+#include "mgos_homeassistant_bh1750.h"
+
+static void bh1750_timer(void *user_data) {
+  struct mgos_homeassistant_object *o = (struct mgos_homeassistant_object *) user_data;
+  if (!o) return;
+  mgos_homeassistant_object_send_status(o);
+}
+
+static void bh1750_stat_light(struct mgos_homeassistant_object *o, struct json_out *json) {
+  struct mgos_homeassistant_bh1750 *d = NULL;
+  float lux = NAN;
+
+  if (!o || !json) return;
+  if (!(d = (struct mgos_homeassistant_bh1750 *) o->user_data)) return;
+
+  lux = mgos_bh1750_read_lux(d->dev, NULL);
+  json_printf(json, "%.1f", lux);
+  //initiate another measurment
+  mgos_bh1750_set_config( d->dev, MGOS_BH1750_MODE_ONCE_HIGH_RES, MGOS_BH1750_MTIME_DEFAULT );
+}
+
+static void bh1750_pre_remove_cb(struct mgos_homeassistant_object *o) {
+  struct mgos_homeassistant_bh1750 *d = NULL;
+  if (!o) return;
+  if (!(d = (struct mgos_homeassistant_bh1750 *) o->user_data)) return;
+  mgos_clear_timer(d->timer);
+  if (d->dev) mgos_bh1750_free(d->dev);
+  free(o->user_data);
+  o->user_data = NULL;
+}
+
+bool mgos_homeassistant_bh1750_fromjson(struct mgos_homeassistant *ha, struct json_token val) {
+  int i2caddr = -1;
+  int period = 60;
+  bool ret = false;
+  struct mgos_homeassistant_object *o = NULL;
+  struct mgos_homeassistant_bh1750 *d = NULL;
+  char object_name[20];
+  char *name = NULL;
+  char *nameptr = NULL;
+
+  if (!ha) goto exit;
+  if (!(d = calloc(1, sizeof(*d)))) goto exit;
+
+  json_scanf(val.ptr, val.len, "{i2caddr:%d,period:%d,name:%Q}", &i2caddr, &period, &name);
+  d->dev = mgos_bh1750_create(i2caddr);
+
+  if (!d->dev) {
+    LOG(LL_ERROR, ("Could not create bh1750 at i2caddr=%d", i2caddr));
+    goto exit;
+  }
+
+  //initiate a one time measurement
+  mgos_bh1750_set_config( d->dev, MGOS_BH1750_MODE_ONCE_HIGH_RES, MGOS_BH1750_MTIME_DEFAULT );
+
+  if (!name) {
+    mgos_homeassistant_object_generate_name(ha, "bh1750_", object_name, sizeof(object_name));
+    nameptr = object_name;
+  } else {
+    nameptr = name;
+  }
+
+  o = mgos_homeassistant_object_add(ha, nameptr, COMPONENT_SENSOR, NULL, NULL, d);
+  if (!o) {
+    LOG(LL_ERROR, ("Could not add object %s to homeassistant", nameptr));
+    goto exit;
+  }
+  o->pre_remove_cb = bh1750_pre_remove_cb;
+
+  // if (!mgos_homeassistant_object_class_add(o, "illuminance", "\"unit_of_measurement\":\"lx\"", bh1750_stat_light)) {
+  if (!mgos_homeassistant_object_class_add(o, "illuminance", "\"unit_of_measurement\":\"lx\"", bh1750_stat_light)) {
+    LOG(LL_ERROR, ("Could not add 'illuminance' class to object %s", nameptr));
+    goto exit;
+  }
+
+  if (period > 0) d->timer = mgos_set_timer(period * 1000, true, bh1750_timer, o);
+
+  ret = true;
+  LOG(LL_DEBUG, ("Successfully created object %s", nameptr));
+exit:
+  if (name) free(name);
+  if (!ret && o) mgos_homeassistant_object_remove(&o);
+  return ret;
+}
+
+#endif  // MGOS_HAVE_bh1750_I2C

src/mgos_homeassistant_bh1750.h

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2020 Mircho Mirev <[email protected]>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+#ifdef MGOS_HAVE_BH1750
+#include <strings.h>
+#include <stdbool.h>
+
+#include "mgos_bh1750.h"
+#include "mgos_homeassistant.h"
+
+struct mgos_homeassistant_bh1750 {
+  struct mgos_bh1750 *dev;
+  mgos_timer_id timer;
+};
+
+bool mgos_homeassistant_bh1750_fromjson(struct mgos_homeassistant *ha, struct json_token val);
+#endif  // MGOS_HAVE_BH1750