From e43c07eb073de27fccd6846d977caaf5df16be70 Mon Sep 17 00:00:00 2001
From: Florian Klemenz <loe.florian@gmail.com>
Date: Fri, 18 Sep 2026 21:11:17 +0000
Subject: [PATCH] adds sending of sensor values to homeassistant via mqtt

---
 mqtt/Makefile       |   5 ++
 mqtt/ina219.service |   9 ++++
 mqtt/ina219.timer   |  12 +++++
 mqtt/mqtt           | 127 ++++++++++++++++++++++++++++++++++++++++++++
 mqtt/send           |  32 +++++++++++
 5 files changed, 185 insertions(+)
 create mode 100644 mqtt/Makefile
 create mode 100644 mqtt/ina219.service
 create mode 100644 mqtt/ina219.timer
 create mode 100755 mqtt/mqtt
 create mode 100755 mqtt/send

diff --git a/mqtt/Makefile b/mqtt/Makefile
new file mode 100644
index 0000000..930b932
--- /dev/null
+++ b/mqtt/Makefile
@@ -0,0 +1,5 @@
+systemd:
+	sudo cp ./ina219.service /etc/systemd/system
+	sudo cp ./ina219.timer /etc/systemd/system
+	sudo systemctl enable ina219.timer
+	sudo systemctl start ina219.timer
diff --git a/mqtt/ina219.service b/mqtt/ina219.service
new file mode 100644
index 0000000..b064c89
--- /dev/null
+++ b/mqtt/ina219.service
@@ -0,0 +1,9 @@
+[Unit]
+Description=Read sensor values
+
+[Service]
+Type=oneshot
+User=root
+Group=root
+WorkingDirectory=/root/git/rpi-ina219/mqtt
+ExecStart=/root/git/rpi-ina219/mqtt/send
diff --git a/mqtt/ina219.timer b/mqtt/ina219.timer
new file mode 100644
index 0000000..34916b6
--- /dev/null
+++ b/mqtt/ina219.timer
@@ -0,0 +1,12 @@
+[Unit]
+Description=Periodically update sensor readings
+
+[Timer]
+#OnCalendar=*-*-* 10:45:00
+#OnBootSec=30sec
+#OnUnitActiveSec=30sec
+OnCalendar=*:0/1
+
+
+[Install]
+WantedBy=timers.target
diff --git a/mqtt/mqtt b/mqtt/mqtt
new file mode 100755
index 0000000..fd5605b
--- /dev/null
+++ b/mqtt/mqtt
@@ -0,0 +1,127 @@
+#!/bin/bash
+
+# MQTT configuration attributes
+# https://www.home-assistant.io/integrations/sensor.mqtt/
+# https://www.home-assistant.io/integrations/switch.mqtt/
+
+# Explanation
+# https://www.youtube.com/watch?v=VHiCtZqllU8
+# https://resinchemtech.blogspot.com/2023/12/mqtt-auto-discovery.html
+
+# Prerequesite
+#apt install mosquitto-clients
+
+LC_NAME="${DEVICE_NAME,,}"
+
+# Device attriutes
+DEVICE_ID="${LC_NAME// /_}"
+DEVICE_MANUFACTURER="custom"
+DEVICE_MODEL="${DEVICE_NAME}" #"custom"
+
+# Sensor attributes
+case ${SENSOR_UNIT} in
+    "W"|"mW")
+        SENSOR_ICON="mdi:lightning-bolt"
+	SENSOR_TYPE="power"
+    ;;
+    "V"|"mV")
+        SENSOR_ICON="mdi:sine-wave"
+	SENSOR_TYPE="voltage"
+    ;;
+    "A"|"mA")
+        SENSOR_ICON="mdi:current-dc"
+	SENSOR_TYPE="current"
+    ;;
+    "C")
+        SENSOR_UNIT="°C"
+    ;;&    
+    "°C")
+        SENSOR_ICON="mdi:thermometer"
+	SENSOR_TYPE="temperature"
+    ;;
+    "%")
+        SENSOR_ICON="mdi:water-percent"
+	SENSOR_TYPE="humidity"
+    ;;
+    *)
+        echo "Unknown sensor unit: ${SENSOR_UNIT}" >&2
+        exit 1
+    ;;
+esac
+SENSOR_ID="${DEVICE_ID}_${SENSOR_TYPE}"
+SENSOR_EXPIRE_AFTER_S="600"
+
+# MQTT attributes
+MQTT_CONFIG_TOPIC="homeassistant/sensor/${SENSOR_ID}/config"
+MQTT_STATE_TOPIC="${LC_NAME// //}/${SENSOR_NAME}/state"
+
+
+
+function send {
+    TOPIC=$1
+    PAYLOAD=$2
+    echo "Sending payload to ${MQTT_BROKER}:${MQTT_PORT}/${TOPIC} ..."
+    echo "TOPIC=$TOPIC"
+    echo "PAYLOAD=$PAYLOAD"
+    if [ -n "${MQTT_USERNAME}" ] && [ -n "${MQTT_PASSWORD}" ]; then
+        mosquitto_pub -h "${MQTT_BROKER:=localhost}" -p "${MQTT_PORT:=1883}" -u "${MQTT_USERNAME}" -P "${MQTT_PASSWORD}" \
+            -t "$TOPIC" \
+            -m "$PAYLOAD"
+    else
+        mosquitto_pub -h "${MQTT_BROKER:=localhost}" -p "${MQTT_PORT:=1883}" \
+            -t "$TOPIC" \
+            -m "$PAYLOAD"
+    fi
+}
+
+function config {
+    send "${MQTT_CONFIG_TOPIC}" "$1"
+}
+
+function state {
+    send "${MQTT_STATE_TOPIC}" "$1"
+}
+
+function setupEntity {
+    config "{\
+\"name\": \"${SENSOR_NAME}\",\
+\"unique_id\": \"${SENSOR_ID}\",\
+\"device_class\": \"${SENSOR_TYPE}\",\
+\"unit_of_measurement\": \"${SENSOR_UNIT}\",\
+\"state_topic\": \"${MQTT_STATE_TOPIC}\",\
+\"expire_after\": \"${SENSOR_EXPIRE_AFTER_S}\",\
+\"icon\": \"${SENSOR_ICON}\",\
+\"device\": {\
+\"name\": \"${DEVICE_NAME}\",\
+\"identifiers\": [\"${DEVICE_ID}\"],\
+\"manufacturer\": \"${DEVICE_MANUFACTURER}\",\
+\"model\": \"${DEVICE_MODEL}\"\
+}}"
+
+#\"firendly_name\": \"${NAME} power\",\
+#    "hw_version":"1.02",
+#     "sw_version":"2.45",
+#     "configuration_url":"http://192.168.1.226"
+}
+
+function deleteEntity {
+    config ""
+}
+
+if [ "$1" == "r" ]; then
+    deleteEntity
+    exit 0 
+fi
+
+if [ -n "$1" ]; then
+    setupEntity
+    state "$1"
+    exit 0 
+fi
+
+if [ -z "$1" ]; then
+    setupEntity
+    exit 0
+fi
+
+exit 1
diff --git a/mqtt/send b/mqtt/send
new file mode 100755
index 0000000..07eeebe
--- /dev/null
+++ b/mqtt/send
@@ -0,0 +1,32 @@
+#!/bin/bash
+
+ROUNDS=5
+
+VOLTAGE=0
+CURRENT=0
+POWER=0
+
+for i in $(seq ${ROUNDS}); do
+    RESULT=$(/usr/bin/ina219)
+
+    VOLTAGE_RAW=$(echo $RESULT | /bin/sed 's/\([0-9]\+\)mV \+\([0-9\.]\+\)mA/\1/')
+    VOLTAGE=$(echo "scale=3; $VOLTAGE+$VOLTAGE_RAW" | /usr/bin/bc)
+
+    CURRENT_RAW=$(echo $RESULT | /bin/sed 's/\([0-9]\+\)mV \+\([0-9\.]\+\)mA/\2/')
+    CURRENT=$(echo "scale=3; $CURRENT+$CURRENT_RAW" | /usr/bin/bc)
+
+done
+    
+VOLTAGE=$(echo "scale=0; $VOLTAGE/$ROUNDS" | /usr/bin/bc)
+CURRENT=$(echo "scale=0; $CURRENT/$ROUNDS" | /usr/bin/bc)
+POWER=$(echo "scale=0; $VOLTAGE*$CURRENT/1000" | /usr/bin/bc)
+
+
+echo "voltage.value $VOLTAGE"
+echo "current.value $CURRENT"
+echo "power.value $POWER"
+
+SENSOR_NAME="voltage" SENSOR_UNIT="mV" DEVICE_NAME="heat-pi ina219" ./mqtt $VOLTAGE
+SENSOR_NAME="current" SENSOR_UNIT="mA" DEVICE_NAME="heat-pi ina219" ./mqtt $CURRENT
+SENSOR_NAME="power" SENSOR_UNIT="mW" DEVICE_NAME="heat-pi ina219" ./mqtt $POWER
+