Add support for SMT100 Soil Moisture Sensor (#3654)

Co-authored-by: Dennis Piecha <d.piecha@ymail.com>

CODEOWNERS

@@ -189,6 +189,7 @@ esphome/components/shutdown/* @esphome/core @jsuanet
 esphome/components/sim800l/* @glmnet
 esphome/components/sm2135/* @BoukeHaarsma23
 esphome/components/sml/* @alengwenus
+esphome/components/smt100/* @piechade
 esphome/components/socket/* @esphome/core
 esphome/components/sonoff_d1/* @anatoly-savchenkov
 esphome/components/spi/* @esphome/core

esphome/components/smt100/__init__.py

@@ -0,0 +1 @@
+CODEOWNERS = ["@piechade"]

esphome/components/smt100/sensor.py

@@ -0,0 +1,94 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.components import sensor, uart
+
+from esphome.const import (
+    CONF_ID,
+    CONF_COUNTS,
+    CONF_DIELECTRIC_CONSTANT,
+    CONF_TEMPERATURE,
+    CONF_MOISTURE,
+    CONF_VOLTAGE,
+    ICON_WATER_PERCENT,
+    DEVICE_CLASS_TEMPERATURE,
+    DEVICE_CLASS_VOLTAGE,
+    STATE_CLASS_MEASUREMENT,
+    UNIT_EMPTY,
+    UNIT_CELSIUS,
+    UNIT_PERCENT,
+    UNIT_VOLT,
+)
+
+DEPENDENCIES = ["uart"]
+
+smt100_ns = cg.esphome_ns.namespace("smt100")
+SMT100 = smt100_ns.class_("SMT100Component", cg.PollingComponent, uart.UARTDevice)
+
+
+CONFIG_SCHEMA = (
+    cv.Schema(
+        {
+            cv.GenerateID(): cv.declare_id(SMT100),
+            cv.Optional(CONF_COUNTS): sensor.sensor_schema(
+                unit_of_measurement=UNIT_EMPTY,
+                accuracy_decimals=0,
+                state_class=STATE_CLASS_MEASUREMENT,
+            ),
+            cv.Optional(CONF_DIELECTRIC_CONSTANT): sensor.sensor_schema(
+                unit_of_measurement=UNIT_EMPTY,
+                accuracy_decimals=2,
+                state_class=STATE_CLASS_MEASUREMENT,
+            ),
+            cv.Optional(CONF_TEMPERATURE): sensor.sensor_schema(
+                unit_of_measurement=UNIT_CELSIUS,
+                accuracy_decimals=2,
+                device_class=DEVICE_CLASS_TEMPERATURE,
+                state_class=STATE_CLASS_MEASUREMENT,
+            ),
+            cv.Optional(CONF_MOISTURE): sensor.sensor_schema(
+                unit_of_measurement=UNIT_PERCENT,
+                icon=ICON_WATER_PERCENT,
+                accuracy_decimals=2,
+                state_class=STATE_CLASS_MEASUREMENT,
+            ),
+            cv.Optional(CONF_VOLTAGE): sensor.sensor_schema(
+                unit_of_measurement=UNIT_VOLT,
+                accuracy_decimals=2,
+                device_class=DEVICE_CLASS_VOLTAGE,
+                state_class=STATE_CLASS_MEASUREMENT,
+            ),
+        }
+    )
+    .extend(cv.polling_component_schema("60s"))
+    .extend(uart.UART_DEVICE_SCHEMA)
+)
+
+FINAL_VALIDATE_SCHEMA = uart.final_validate_device_schema(
+    "smt100", baud_rate=9600, require_rx=True, require_tx=True
+)
+
+
+async def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    await cg.register_component(var, config)
+    await uart.register_uart_device(var, config)
+
+    if CONF_COUNTS in config:
+        sens = await sensor.new_sensor(config[CONF_COUNTS])
+        cg.add(var.set_counts_sensor(sens))
+
+    if CONF_DIELECTRIC_CONSTANT in config:
+        sens = await sensor.new_sensor(config[CONF_DIELECTRIC_CONSTANT])
+        cg.add(var.set_dielectric_constant_sensor(sens))
+
+    if CONF_TEMPERATURE in config:
+        sens = await sensor.new_sensor(config[CONF_TEMPERATURE])
+        cg.add(var.set_temperature_sensor(sens))
+
+    if CONF_MOISTURE in config:
+        sens = await sensor.new_sensor(config[CONF_MOISTURE])
+        cg.add(var.set_moisture_sensor(sens))
+
+    if CONF_VOLTAGE in config:
+        sens = await sensor.new_sensor(config[CONF_VOLTAGE])
+        cg.add(var.set_voltage_sensor(sens))

esphome/components/smt100/smt100.cpp

@@ -0,0 +1,84 @@
+#include "smt100.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace smt100 {
+
+static const char *const TAG = "smt100";
+
+void SMT100Component::update() {
+  ESP_LOGV(TAG, "Sending measurement request");
+  this->write_str("GetAllMeasurements!\r");
+}
+
+void SMT100Component::loop() {
+  static char buffer[MAX_LINE_LENGTH];
+  while (this->available() != 0) {
+    if (readline_(read(), buffer, MAX_LINE_LENGTH) > 0) {
+      int counts = (int) strtol((strtok(buffer, ",")), nullptr, 10);
+      float dielectric_constant = (float) strtod((strtok(nullptr, ",")), nullptr);
+      float moisture = (float) strtod((strtok(nullptr, ",")), nullptr);
+      float temperature = (float) strtod((strtok(nullptr, ",")), nullptr);
+      float voltage = (float) strtod((strtok(nullptr, ",")), nullptr);
+
+      if (this->counts_sensor_ != nullptr) {
+        counts_sensor_->publish_state(counts);
+      }
+
+      if (this->dielectric_constant_sensor_ != nullptr) {
+        dielectric_constant_sensor_->publish_state(dielectric_constant);
+      }
+
+      if (this->moisture_sensor_ != nullptr) {
+        moisture_sensor_->publish_state(moisture);
+      }
+
+      if (this->temperature_sensor_ != nullptr) {
+        temperature_sensor_->publish_state(temperature);
+      }
+
+      if (this->voltage_sensor_ != nullptr) {
+        voltage_sensor_->publish_state(voltage);
+      }
+    }
+  }
+}
+
+float SMT100Component::get_setup_priority() const { return setup_priority::DATA; }
+
+void SMT100Component::dump_config() {
+  ESP_LOGCONFIG(TAG, "SMT100:");
+
+  LOG_SENSOR(TAG, "Counts", this->temperature_sensor_);
+  LOG_SENSOR(TAG, "Dielectric Constant", this->temperature_sensor_);
+  LOG_SENSOR(TAG, "Temperature", this->temperature_sensor_);
+  LOG_SENSOR(TAG, "Moisture", this->moisture_sensor_);
+  LOG_UPDATE_INTERVAL(this);
+  this->check_uart_settings(9600);
+}
+
+int SMT100Component::readline_(int readch, char *buffer, int len) {
+  static int pos = 0;
+  int rpos;
+
+  if (readch > 0) {
+    switch (readch) {
+      case '\n':  // Ignore new-lines
+        break;
+      case '\r':  // Return on CR
+        rpos = pos;
+        pos = 0;  // Reset position index ready for next time
+        return rpos;
+      default:
+        if (pos < len - 1) {
+          buffer[pos++] = readch;
+          buffer[pos] = 0;
+        }
+    }
+  }
+  // No end of line has been found, so return -1.
+  return -1;
+}
+
+}  // namespace smt100
+}  // namespace esphome

esphome/components/smt100/smt100.h

@@ -0,0 +1,43 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/sensor/sensor.h"
+#include "esphome/components/uart/uart.h"
+
+namespace esphome {
+namespace smt100 {
+
+class SMT100Component : public PollingComponent, public uart::UARTDevice {
+  static const uint16_t MAX_LINE_LENGTH = 31;
+
+ public:
+  SMT100Component() = default;
+
+  void dump_config() override;
+  void loop() override;
+  void update() override;
+
+  float get_setup_priority() const override;
+
+  void set_counts_sensor(sensor::Sensor *counts_sensor) { this->counts_sensor_ = counts_sensor; }
+  void set_dielectric_constant_sensor(sensor::Sensor *dielectric_constant_sensor) {
+    this->dielectric_constant_sensor_ = dielectric_constant_sensor;
+  }
+  void set_temperature_sensor(sensor::Sensor *temperature_sensor) { this->temperature_sensor_ = temperature_sensor; }
+  void set_moisture_sensor(sensor::Sensor *moisture_sensor) { this->moisture_sensor_ = moisture_sensor; }
+  void set_voltage_sensor(sensor::Sensor *voltage_sensor) { this->voltage_sensor_ = voltage_sensor; }
+
+ protected:
+  int readline_(int readch, char *buffer, int len);
+
+  sensor::Sensor *counts_sensor_{nullptr};
+  sensor::Sensor *dielectric_constant_sensor_{nullptr};
+  sensor::Sensor *moisture_sensor_{nullptr};
+  sensor::Sensor *temperature_sensor_{nullptr};
+  sensor::Sensor *voltage_sensor_{nullptr};
+
+  uint32_t last_transmission_{0};
+};
+
+}  // namespace smt100
+}  // namespace esphome

esphome/const.py

@@ -126,6 +126,7 @@ CONF_COOL_MODE = "cool_mode"
 CONF_COOL_OVERRUN = "cool_overrun"
 CONF_COUNT = "count"
 CONF_COUNT_MODE = "count_mode"
+CONF_COUNTS = "counts"
 CONF_COURSE = "course"
 CONF_CRON = "cron"
 CONF_CS_PIN = "cs_pin"
@@ -164,6 +165,7 @@ CONF_DELTA = "delta"
 CONF_DEVICE = "device"
 CONF_DEVICE_CLASS = "device_class"
 CONF_DEVICE_FACTOR = "device_factor"
+CONF_DIELECTRIC_CONSTANT = "dielectric_constant"
 CONF_DIMENSIONS = "dimensions"
 CONF_DIO_PIN = "dio_pin"
 CONF_DIR_PIN = "dir_pin"

tests/test3.yaml

@@ -270,6 +270,10 @@ uart:
     tx_pin: GPIO4
     rx_pin: GPIO5
     baud_rate: 9600
+  - id: uart10
+    tx_pin: GPIO4
+    rx_pin: GPIO5
+    baud_rate: 9600
 
 modbus:
   uart_id: uart1
@@ -755,6 +759,19 @@ sensor:
     temperature:
       name: "mlxtemp"
       oversampling: 2
+  - platform: smt100
+    uart_id: uart10
+    counts:
+      name: "Counts"
+    dielectric_constant:
+      name: "Dielectric Constant"
+    temperature:
+      name: "Temperature"
+    moisture:
+      name: "Moisture"
+    voltage:
+      name: "Voltage"
+    update_interval: 60s
 time:
   - platform: homeassistant