mqtt discovery: Set icon for soil moisture sensor

The LiPo battery apparently ranges from 3.0 V to 3.95 V.  Since we know
the range, we can report the current level as a percentage, which Home
Assistant will display.

We'll leave the original voltage reading in the MQTT state payload for
diagnostic purposes.

constants.h

@@ -9,4 +9,7 @@
 #define TOPIC_ERRORS "garden/errors"
 #define TOPIC_STATE "garden/state"
 
-#define SLEEP_MILLIS (1000 * 60)
+#define SLEEP_MILLIS_EARLY (1000 * 60)
+#define SLEEP_MILLIS (1000 * 60 * 60)
+
+#define VERSION __DATE__ " " __TIME__

gardensensor.ino

@@ -11,6 +11,8 @@
 
 INCTXT(RootCA, "isrgrootx1.pem");
 
+RTC_DATA_ATTR uint32_t boot_count = 0;
+
 WiFiClientSecure sock;
 PubSubClient mqtt(sock);
 
@@ -18,19 +20,24 @@ Values values;
 Adafruit_seesaw ss;
 
 void setup() {
-    delay(1000);  // VSCode is slow to open the serial console after upload
-
     Serial.begin(115200);
     pinMode(13, OUTPUT);
     digitalWrite(13, 1);
 
+    // VSCode is slow to open the serial console after upload
+    if (boot_count == 0) {
+        delay(1000);
+    }
+    boot_count++;
+    Serial.printf("This is boot number %d\n", boot_count);
+
     if (!wifi_connect()) {
         Serial.printf("Failed to connect to WiFi, status %s\n", WiFi.status());
-        reboot();
+        retry_after_minutes(1);
     }
     if (!mqtt_connect()) {
         Serial.println("Could not connect to MQTT");
-        reboot();
+        retry_after_minutes(1);
     }
 
     if (!publish_all_config(&mqtt, WiFi.macAddress().c_str())) {
@@ -42,20 +49,22 @@ void setup() {
         auto msg = "Seesaw not found";
         Serial.println(msg);
         mqtt_send_error(msg);
-        reboot();
+        retry_after_minutes(1);
     }
 
+    values.boot_count = boot_count;
     if (!values.read(&ss)) {
         auto msg = "Failed to get sensor values";
         Serial.println(msg);
         mqtt_send_error(msg);
-        reboot();
+        retry_after_minutes(1);
     } else {
         Serial.println("Got Values:");
         Serial.printf("  Moisture: %d\n", values.moisture);
         Serial.printf("  Temperature: %.02f\n", values.temperature);
         Serial.printf("  Battery: %.02f\n", values.battery);
         Serial.printf("  RSSI: %d\n", values.rssi);
+        Serial.printf("  Boot Count: %d\n", values.boot_count);
         if (!values.send(&mqtt, TOPIC_STATE)) {
             Serial.println("Failed to send sensor values");
         }
@@ -65,9 +74,11 @@ void setup() {
     mqtt.disconnect();
     delay(1000);
 
-    Serial.println("Entering deep sleep ...");
+    unsigned long timer =
+        ((boot_count <= 5 ? SLEEP_MILLIS_EARLY : SLEEP_MILLIS) - millis());
+    Serial.printf("Entering deep sleep for %d milliseconds...\n", timer);
     Serial.flush();
-    esp_sleep_enable_timer_wakeup((SLEEP_MILLIS - millis()) * 1000);
+    esp_sleep_enable_timer_wakeup(timer * 1000);
     esp_deep_sleep_start();
 }
 
@@ -76,15 +87,6 @@ void loop() {
     while (1) delay(1471228928);
 }
 
-void error_led_blink() {
-    while (1) {
-        digitalWrite(13, 1);
-        delay(500);
-        digitalWrite(13, 0);
-        delay(500);
-    }
-}
-
 boolean wifi_connect() {
     Serial.printf("Connecting to WiFi (%s) ", CFG_WIFI_SSID);
     WiFi.begin(CFG_WIFI_SSID, CFG_WIFI_PSK);
@@ -137,10 +139,6 @@ boolean mqtt_connect() {
     return true;
 }
 
-void mqtt_send_error(const __FlashStringHelper* msg) {
-    mqtt_send_error((const char*)msg);
-}
-
 void mqtt_send_error(const char* msg) {
     if (!mqtt.connected()) {
         Serial.println("MQTT client not connected, cannot send error message");
@@ -149,11 +147,10 @@ void mqtt_send_error(const char* msg) {
     mqtt.publish(TOPIC_ERRORS, msg);
 }
 
-void reboot() {
+void retry_after_minutes(int minutes) {
     if (mqtt.connected()) {
         mqtt.disconnect();
     }
-    Serial.println("Rebooting in 2 seconds");
-    delay(2000);
-    ESP.restart();
+    esp_sleep_enable_timer_wakeup(minutes * 60 * 1000 * 1000);
+    esp_deep_sleep_start();
 }

mqtt_discovery.cpp

@@ -4,32 +4,52 @@
 
 #include "constants.h"
 
+struct sensor_config {
+    const char* name;
+    const char* unique_id;
+    const char* value_template;
+    const char* identifier;
+    const char* device_class;
+    const char* unit;
+    const char* state_class;
+    const char* entity_category;
+    const char* icon;
+};
+
 static bool publish_config(PubSubClient* mqtt, const char* topic,
-                           const char* name, const char* unique_id,
-                           const char* value_template, const char* identifier,
-                           const char* device_class, const char* unit) {
-    StaticJsonDocument<256> doc;
-    doc["unique_id"] = unique_id;
-    doc["name"] = name;
+                           const struct sensor_config* config) {
+    StaticJsonDocument<512> doc;
+    doc["unique_id"] = config->unique_id;
+    doc["name"] = config->name;
     doc["state_topic"] = TOPIC_STATE;
-    doc["value_template"] = value_template;
-    if (device_class != NULL) {
-        doc["device_class"] = device_class;
+    doc["value_template"] = config->value_template;
+    if (config->device_class != NULL) {
+        doc["device_class"] = config->device_class;
     }
-    if (unit != NULL) {
-        doc["unit_of_measurement"] = unit;
+    if (config->unit != NULL) {
+        doc["unit_of_measurement"] = config->unit;
+    }
+    if (config->state_class != NULL) {
+        doc["state_class"] = config->state_class;
+    }
+    if (config->entity_category != NULL) {
+        doc["entity_category"] = config->entity_category;
+    }
+    if (config->icon != NULL) {
+        doc["icon"] = config->icon;
     }
     auto device = doc.createNestedObject("device");
     device["manufacturer"] = DEVICE_MANUFACTURER;
     device["name"] = DEVICE_NAME;
     device["model"] = DEVICE_MODEL;
+    device["sw_version"] = VERSION;
     auto ident = device.createNestedArray("identifiers");
-    ident.add(identifier);
+    ident.add(config->identifier);
     String msg;
     serializeJson(doc, msg);
     auto payload = msg.c_str();
     Serial.printf("Publishing configuration for %s (%zd bytes) to %s ... ",
-                  unique_id, strlen(payload), topic);
+                  config->unique_id, strlen(payload), topic);
     auto r = mqtt->publish(topic, payload, true);
     Serial.println(r ? "OK" : "FAILED");
     return r;
@@ -37,18 +57,51 @@ static bool publish_config(PubSubClient* mqtt, const char* topic,
 
 bool publish_all_config(PubSubClient* mqtt, const char* ident) {
     bool ret = true;
-    publish_config(mqtt, TOPIC_CFG_MOISTURE, "Garden Sensor Moisture",
-                   "sensor.garden_sensor_moisture",
-                   "{{ value_json.moisture }}", ident, NULL, NULL);
-    publish_config(mqtt, TOPIC_CFG_TEMPERATURE, "Garden Sensor Temperature",
-                   "sensor.garden_sensor_temperature",
-                   "{{ value_json.temperature }}", ident, "temperature", "°C");
-    publish_config(mqtt, TOPIC_CFG_BATTERY, "Garden Sensor Battery Level",
-                   "sensor.garden_sensor_battery_level",
-                   "{{ value_json.battery_level }}", ident, "voltage", "V");
-    publish_config(mqtt, TOPIC_CFG_RSSI, "Garden Sensor Signal Strength",
-                   "sensor.garden_sensor_rssi", "{{ value_json.rssi }}", ident,
-                   "signal_strength", "dBm");
+    struct sensor_config moisture = {
+        .name = "Garden Sensor Moisture",
+        .unique_id = "sensor.garden_sensor_moisture",
+        .value_template = "{{ value_json.moisture }}",
+        .identifier = ident,
+        .device_class = NULL,
+        .unit = NULL,
+        .state_class = "measurement",
+        .entity_category = NULL,
+        .icon = "mdi:water",
+    };
+    publish_config(mqtt, TOPIC_CFG_MOISTURE, &moisture);
+    struct sensor_config temperature = {
+        .name = "Garden Sensor Temperature",
+        .unique_id = "sensor.garden_sensor_temperature",
+        .value_template = "{{ value_json.temperature }}",
+        .identifier = ident,
+        .device_class = "temperature",
+        .unit = "°C",
+        .state_class = NULL,
+        .entity_category = NULL,
+    };
+    publish_config(mqtt, TOPIC_CFG_TEMPERATURE, &temperature);
+    struct sensor_config battery = {
+        .name = "Garden Sensor Battery",
+        .unique_id = "sensor.garden_sensor_battery",
+        .value_template = "{{ value_json.battery }}",
+        .identifier = ident,
+        .device_class = "battery",
+        .unit = "%",
+        .state_class = NULL,
+        .entity_category = "diagnostic",
+    };
+    publish_config(mqtt, TOPIC_CFG_BATTERY, &battery);
+    struct sensor_config signal = {
+        .name = "Garden Sensor Signal Strength",
+        .unique_id = "sensor.garden_sensor_rssi",
+        .value_template = "{{ value_json.rssi }}",
+        .identifier = ident,
+        .device_class = "signal_strength",
+        .unit = "dBm",
+        .state_class = NULL,
+        .entity_category = "diagnostic",
+    };
+    publish_config(mqtt, TOPIC_CFG_RSSI, &signal);
 
     return ret;
 }

values.cpp

@@ -16,11 +16,13 @@ bool Values::read(Adafruit_seesaw* ss) {
 }
 
 bool Values::send(PubSubClient* mqtt, const char* topic) {
-    StaticJsonDocument<64> doc;
+    StaticJsonDocument<96> doc;
     doc["moisture"] = moisture;
     doc["temperature"] = round2(temperature);
     doc["battery_level"] = round2(battery);
+    doc["battery"] = (int)((battery - 3) / 0.95 * 100);
     doc["rssi"] = rssi;
+    doc["boot_count"] = boot_count;
 
     String msg;
     serializeJson(doc, msg);

values.hpp

@@ -7,6 +7,7 @@ class Values {
     float temperature;
     float battery;
     int8_t rssi;
+    uint32_t boot_count;
 
     Values() {};
     ~Values() {};