[MAX31888] Add temperature sensor (#13567)

Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>
Co-authored-by: J. Nick Koston <nick@home-assistant.io>

CODEOWNERS

@@ -343,6 +343,7 @@ esphome/components/mapping/* @clydebarrow
 esphome/components/matrix_keypad/* @ssieb
 esphome/components/max17043/* @blacknell
 esphome/components/max31865/* @DAVe3283
+esphome/components/max31888/* @JiriPrchal
 esphome/components/max44009/* @berfenger
 esphome/components/max6956/* @looping40
 esphome/components/max7219digit/* @rspaargaren

esphome/components/max31888/__init__.py

@@ -0,0 +1,2 @@
+CODEOWNERS = ["@JiriPrchal"]
+DOMAIN = "max31888"

esphome/components/max31888/max31888.cpp

@@ -0,0 +1,95 @@
+#include "max31888.h"
+#include "esphome/core/helpers.h"
+#include "esphome/core/log.h"
+
+namespace esphome::max31888 {
+
+ESPHOME_LOG_TAG(TAG, "max31888");
+
+static constexpr uint32_t CONVERSION_TIMEOUT_ID = 0;
+
+static constexpr uint8_t MAX31888_COMMAND_START_CONVERSION = 0x44;
+static constexpr uint8_t MAX31888_COMMAND_READ = 0x33;
+static constexpr uint8_t MAX31888_COMMAND_SOFT_RESET = 0x82;
+static constexpr uint8_t MAX31888_REGISTER_FIFO_DATA = 0x08;
+static constexpr uint8_t MAX31888_FIFO_READ_LENGTH = 0x01;  // number of bytes to read, minus one
+static constexpr uint16_t MAX31888_CONVERSION_TIME_MS = 20;
+static constexpr float MAX31888_DEGREES_PER_LSB = 0.005f;
+
+// Sends a command and checks the checksum the device appends to it (Maxim CRC-16 over the command byte,
+// sent inverted and low byte first)
+bool MAX31888Sensor::send_checked_command_(uint8_t command) {
+  if (!this->send_command_(command)) {
+    this->status_set_warning(LOG_STR("bus reset failed"));
+    return false;
+  }
+  const uint8_t low = this->bus_->read8();
+  const uint8_t high = this->bus_->read8();
+  if (crc16(&command, 1, 0, 0xa001, false, true) != encode_uint16(high, low)) {
+    this->status_set_warning(LOG_STR("command checksum invalid"));
+    return false;
+  }
+  return true;
+}
+
+void MAX31888Sensor::setup() {
+  if (!this->check_address_or_index_())
+    return;
+  if (!this->send_checked_command_(MAX31888_COMMAND_SOFT_RESET)) {
+    this->mark_failed();
+  }
+}
+
+void MAX31888Sensor::dump_config() {
+  ESP_LOGCONFIG(TAG, "MAX31888 Sensor:");
+  if (this->address_ == 0) {
+    ESP_LOGW(TAG, "  Unable to select an address");
+    return;
+  }
+  LOG_ONE_WIRE_DEVICE(this);
+  LOG_UPDATE_INTERVAL(this);
+}
+
+void MAX31888Sensor::update() {
+  if (this->address_ == 0)
+    return;
+
+  if (!this->send_checked_command_(MAX31888_COMMAND_START_CONVERSION)) {
+    this->publish_state(NAN);
+    return;
+  }
+
+  this->set_timeout(CONVERSION_TIMEOUT_ID, MAX31888_CONVERSION_TIME_MS, [this] {
+    int16_t raw;
+    if (!this->read_temperature_(raw)) {
+      this->publish_state(NAN);
+      return;
+    }
+    const float temperature = raw * MAX31888_DEGREES_PER_LSB;
+    ESP_LOGD(TAG, "'%s': Got Temperature=%.3f°C", this->get_name().c_str(), temperature);
+    this->status_clear_warning();
+    this->publish_state(temperature);
+  });
+}
+
+bool MAX31888Sensor::read_temperature_(int16_t &raw) {
+  // The checksum covers the command and its two arguments as well as the data
+  uint8_t frame[7] = {MAX31888_COMMAND_READ, MAX31888_REGISTER_FIFO_DATA, MAX31888_FIFO_READ_LENGTH};
+  if (!this->send_command_(frame[0])) {
+    this->status_set_warning(LOG_STR("bus reset failed"));
+    return false;
+  }
+  this->bus_->write8(frame[1]);
+  this->bus_->write8(frame[2]);
+  for (size_t i = 3; i < sizeof(frame); i++) {
+    frame[i] = this->bus_->read8();
+  }
+  if (crc16(frame, 5, 0, 0xa001, false, true) != encode_uint16(frame[6], frame[5])) {
+    this->status_set_warning(LOG_STR("checksum invalid"));
+    return false;
+  }
+  raw = static_cast<int16_t>(encode_uint16(frame[3], frame[4]));
+  return true;
+}
+
+}  // namespace esphome::max31888

esphome/components/max31888/max31888.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/sensor/sensor.h"
+#include "esphome/components/one_wire/one_wire.h"
+
+namespace esphome::max31888 {
+
+class MAX31888Sensor final : public PollingComponent, public sensor::Sensor, public one_wire::OneWireDevice {
+ public:
+  void setup() override;
+  void update() override;
+  void dump_config() override;
+
+ protected:
+  bool send_checked_command_(uint8_t command);
+  /// Reads the latest conversion from the FIFO; false when the bus or the checksum fails
+  bool read_temperature_(int16_t &raw);
+};
+
+}  // namespace esphome::max31888

esphome/components/max31888/sensor.py

@@ -0,0 +1,36 @@
+import esphome.codegen as cg
+from esphome.components import one_wire, sensor
+import esphome.config_validation as cv
+from esphome.const import (
+    DEVICE_CLASS_TEMPERATURE,
+    STATE_CLASS_MEASUREMENT,
+    UNIT_CELSIUS,
+)
+from esphome.types import ConfigType
+
+max31888_ns = cg.esphome_ns.namespace("max31888")
+
+MAX31888Sensor = max31888_ns.class_(
+    "MAX31888Sensor",
+    cg.PollingComponent,
+    sensor.Sensor,
+    one_wire.OneWireDevice,
+)
+
+CONFIG_SCHEMA = (
+    sensor.sensor_schema(
+        MAX31888Sensor,
+        unit_of_measurement=UNIT_CELSIUS,
+        accuracy_decimals=2,
+        device_class=DEVICE_CLASS_TEMPERATURE,
+        state_class=STATE_CLASS_MEASUREMENT,
+    )
+    .extend(one_wire.one_wire_device_schema())
+    .extend(cv.polling_component_schema("60s"))
+)
+
+
+async def to_code(config: ConfigType) -> None:
+    var = await sensor.new_sensor(config)
+    await cg.register_component(var, config)
+    await one_wire.register_one_wire_device(var, config)

esphome/components/one_wire/one_wire_bus.cpp

@@ -10,6 +10,7 @@ static const uint8_t DALLAS_MODEL_DS1822 = 0x22;
 static const uint8_t DALLAS_MODEL_DS18B20 = 0x28;
 static const uint8_t DALLAS_MODEL_DS1825 = 0x3B;
 static const uint8_t DALLAS_MODEL_DS28EA00 = 0x42;
+static const uint8_t MAXIM_MODEL_MAX31888 = 0x54;
 
 const uint8_t ONE_WIRE_ROM_SELECT = 0x55;
 const uint8_t ONE_WIRE_ROM_SEARCH = 0xF0;
@@ -76,6 +77,8 @@ const LogString *OneWireBus::get_model_str(uint8_t model) {
       return LOG_STR("DS1825");
     case DALLAS_MODEL_DS28EA00:
       return LOG_STR("DS28EA00");
+    case MAXIM_MODEL_MAX31888:
+      return LOG_STR("MAX31888");
     default:
       return LOG_STR("Unknown");
   }

tests/components/max31888/common.yaml

@@ -0,0 +1,9 @@
+sensor:
+  - platform: max31888
+    one_wire_id: one_wire_bus
+    address: 0x1C0000031EDD2A54
+    name: MAX31888 Temperature 1
+  - platform: max31888
+    one_wire_id: one_wire_bus
+    name: MAX31888 Temperature 2
+    index: 1

tests/components/max31888/test.esp32-idf.yaml

@@ -0,0 +1,3 @@
+packages:
+  one_wire: !include ../../test_build_components/common/one_wire/esp32-idf.yaml
+  max31888: !include common.yaml

tests/components/max31888/test.esp8266-ard.yaml

@@ -0,0 +1,3 @@
+packages:
+  one_wire: !include ../../test_build_components/common/one_wire/esp8266-ard.yaml
+  max31888: !include common.yaml

tests/components/max31888/test.rp2040-ard.yaml

@@ -0,0 +1,3 @@
+packages:
+  one_wire: !include ../../test_build_components/common/one_wire/rp2040-ard.yaml
+  max31888: !include common.yaml

tests/test_build_components/common/README.md

@@ -125,6 +125,11 @@ Components using `modbus` packages automatically get `uart` as well.
 - **RP2040**: SCL=GPIO5, SDA=GPIO4
 - **BK72xx**: SCL=P20, SDA=P21
 
+### 1-Wire
+- **ESP32 IDF**: GPIO4
+- **ESP8266**: GPIO13
+- **RP2040**: GPIO10
+
 ### I2C Low Frequency (10kHz)
 Same pin allocations as standard I2C, but with 10kHz frequency for components requiring slower speeds.
 

tests/test_build_components/common/one_wire/esp32-idf.yaml

@@ -0,0 +1,10 @@
+# Common 1-Wire configuration for esp32-idf tests
+# Provides a shared 1-Wire bus that all components can use
+
+substitutions:
+  one_wire_pin: GPIO4
+
+one_wire:
+  - platform: gpio
+    id: one_wire_bus
+    pin: ${one_wire_pin}

tests/test_build_components/common/one_wire/esp8266-ard.yaml

@@ -0,0 +1,10 @@
+# Common 1-Wire configuration for esp8266-ard tests
+# Provides a shared 1-Wire bus that all components can use
+
+substitutions:
+  one_wire_pin: GPIO13
+
+one_wire:
+  - platform: gpio
+    id: one_wire_bus
+    pin: ${one_wire_pin}

tests/test_build_components/common/one_wire/rp2040-ard.yaml

@@ -0,0 +1,10 @@
+# Common 1-Wire configuration for rp2040-ard tests
+# Provides a shared 1-Wire bus that all components can use
+
+substitutions:
+  one_wire_pin: GPIO10
+
+one_wire:
+  - platform: gpio
+    id: one_wire_bus
+    pin: ${one_wire_pin}