From 1ea3de712ee0074e44ef36f7f3bf4be8a6dfd62a Mon Sep 17 00:00:00 2001
From: "Dustin C. Hatch" <dustin@hatch.name>
Date: Mon, 16 May 2022 21:40:41 -0500
Subject: [PATCH] values: Report battery level in percentage

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.
---
 mqtt_discovery.cpp | 10 +++++-----
 values.cpp         |  1 +
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/mqtt_discovery.cpp b/mqtt_discovery.cpp
index dcf5134..a7c4465 100644
--- a/mqtt_discovery.cpp
+++ b/mqtt_discovery.cpp
@@ -75,12 +75,12 @@ bool publish_all_config(PubSubClient* mqtt, const char* ident) {
     };
     publish_config(mqtt, TOPIC_CFG_TEMPERATURE, &temperature);
     struct sensor_config battery = {
-        .name = "Garden Sensor Battery Level",
-        .unique_id = "sensor.garden_sensor_battery_level",
-        .value_template = "{{ value_json.battery_level }}",
+        .name = "Garden Sensor Battery",
+        .unique_id = "sensor.garden_sensor_battery",
+        .value_template = "{{ value_json.battery }}",
         .identifier = ident,
-        .device_class = "voltage",
-        .unit = "V",
+        .device_class = "battery",
+        .unit = "%",
         .state_class = NULL,
         .entity_category = "diagnostic",
     };
diff --git a/values.cpp b/values.cpp
index 97ed9ff..67dc8cc 100644
--- a/values.cpp
+++ b/values.cpp
@@ -20,6 +20,7 @@ bool Values::send(PubSubClient* mqtt, const char* topic) {
     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;