diff --git a/esphome/components/cse7766/cse7766.cpp b/esphome/components/cse7766/cse7766.cpp
index 358453a63a..6c014138fd 100644
--- a/esphome/components/cse7766/cse7766.cpp
+++ b/esphome/components/cse7766/cse7766.cpp
@@ -172,6 +172,7 @@ void CSE7766Component::dump_config() {
   LOG_SENSOR("  ", "Voltage", this->voltage_sensor_);
   LOG_SENSOR("  ", "Current", this->current_sensor_);
   LOG_SENSOR("  ", "Power", this->power_sensor_);
+  this->check_uart_settings(4800);
 }
 
 }  // namespace cse7766
diff --git a/esphome/components/mhz19/mhz19.cpp b/esphome/components/mhz19/mhz19.cpp
index 36ccf70d84..8e28d04dea 100644
--- a/esphome/components/mhz19/mhz19.cpp
+++ b/esphome/components/mhz19/mhz19.cpp
@@ -94,6 +94,7 @@ void MHZ19Component::dump_config() {
   ESP_LOGCONFIG(TAG, "MH-Z19:");
   LOG_SENSOR("  ", "CO2", this->co2_sensor_);
   LOG_SENSOR("  ", "Temperature", this->temperature_sensor_);
+  this->check_uart_settings(9600);
 
   if (this->abc_boot_logic_ == MHZ19_ABC_ENABLED) {
     ESP_LOGCONFIG(TAG, "  Automatic baseline calibration enabled on boot");
diff --git a/esphome/components/modbus/__init__.py b/esphome/components/modbus/__init__.py
new file mode 100644
index 0000000000..88105b7baf
--- /dev/null
+++ b/esphome/components/modbus/__init__.py
@@ -0,0 +1,43 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.components import uart
+from esphome.const import CONF_ID, CONF_ADDRESS
+from esphome.core import coroutine
+
+DEPENDENCIES = ['uart']
+
+modbus_ns = cg.esphome_ns.namespace('modbus')
+Modbus = modbus_ns.class_('Modbus', cg.Component, uart.UARTDevice)
+ModbusDevice = modbus_ns.class_('ModbusDevice')
+MULTI_CONF = True
+
+CONF_MODBUS_ID = 'modbus_id'
+CONFIG_SCHEMA = cv.Schema({
+    cv.GenerateID(): cv.declare_id(Modbus),
+}).extend(cv.COMPONENT_SCHEMA).extend(uart.UART_DEVICE_SCHEMA)
+
+
+def to_code(config):
+    cg.add_global(modbus_ns.using)
+    var = cg.new_Pvariable(config[CONF_ID])
+    yield cg.register_component(var, config)
+
+    yield uart.register_uart_device(var, config)
+
+
+def modbus_device_schema(default_address):
+    schema = {
+        cv.GenerateID(CONF_MODBUS_ID): cv.use_id(Modbus),
+    }
+    if default_address is None:
+        schema[cv.Required(CONF_ADDRESS)] = cv.hex_uint8_t
+    else:
+        schema[cv.Optional(CONF_ADDRESS, default=default_address)] = cv.hex_uint8_t
+    return cv.Schema(schema)
+
+
+@coroutine
+def register_modbus_device(var, config):
+    parent = yield cg.get_variable(config[CONF_MODBUS_ID])
+    cg.add(var.set_parent(parent))
+    cg.add(var.set_address(config[CONF_ADDRESS]))
diff --git a/esphome/components/modbus/modbus.cpp b/esphome/components/modbus/modbus.cpp
new file mode 100644
index 0000000000..92505c6429
--- /dev/null
+++ b/esphome/components/modbus/modbus.cpp
@@ -0,0 +1,119 @@
+#include "modbus.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace modbus {
+
+static const char *TAG = "modbus";
+
+void Modbus::loop() {
+  const uint32_t now = millis();
+  if (now - this->last_modbus_byte_ > 50) {
+    this->rx_buffer_.clear();
+    this->last_modbus_byte_ = now;
+  }
+
+  while (this->available()) {
+    uint8_t byte;
+    this->read_byte(&byte);
+    if (this->parse_modbus_byte_(byte)) {
+      this->last_modbus_byte_ = now;
+    } else {
+      this->rx_buffer_.clear();
+    }
+  }
+}
+
+uint16_t crc16(uint8_t *data, uint8_t len) {
+  uint16_t crc = 0xFFFF;
+  while (len--) {
+    crc ^= *data++;
+    for (uint8_t i = 0; i < 8; i++) {
+      if ((crc & 0x01) != 0) {
+        crc >>= 1;
+        crc ^= 0xA001;
+      } else {
+        crc >>= 1;
+      }
+    }
+  }
+  return crc;
+}
+
+bool Modbus::parse_modbus_byte_(uint8_t byte) {
+  size_t at = this->rx_buffer_.size();
+  this->rx_buffer_.push_back(byte);
+  uint8_t *raw = &this->rx_buffer_[0];
+
+  // Byte 0: modbus address (match all)
+  if (at == 0)
+    return true;
+  uint8_t address = raw[0];
+
+  // Byte 1: Function (msb indicates error)
+  if (at == 1)
+    return (byte & 0x80) != 0x80;
+
+  // Byte 2: Size (with modbus rtu function code 4/3)
+  // See also https://en.wikipedia.org/wiki/Modbus
+  if (at == 2)
+    return true;
+
+  uint8_t data_len = raw[2];
+  // Byte 3..3+data_len-1: Data
+  if (at < 3 + data_len)
+    return true;
+
+  // Byte 3+data_len: CRC_LO (over all bytes)
+  if (at == 3 + data_len)
+    return true;
+  // Byte 3+len+1: CRC_HI (over all bytes)
+  uint16_t computed_crc = crc16(raw, 3 + data_len);
+  uint16_t remote_crc = uint16_t(raw[3 + data_len]) | (uint16_t(raw[3 + data_len]) << 8);
+  if (computed_crc != remote_crc) {
+    ESP_LOGW(TAG, "Modbus CRC Check failed! %02X!=%02X", computed_crc, remote_crc);
+    return false;
+  }
+
+  std::vector<uint8_t> data(this->rx_buffer_.begin() + 3, this->rx_buffer_.begin() + 3 + data_len);
+
+  bool found = false;
+  for (auto *device : this->devices_) {
+    if (device->address_ == address) {
+      device->on_modbus_data(data);
+      found = true;
+    }
+  }
+  if (!found) {
+    ESP_LOGW(TAG, "Got Modbus frame from unknown address 0x%02X!", address);
+  }
+
+  // return false to reset buffer
+  return false;
+}
+
+void Modbus::dump_config() {
+  ESP_LOGCONFIG(TAG, "Modbus:");
+  this->check_uart_settings(9600, 2);
+}
+float Modbus::get_setup_priority() const {
+  // After UART bus
+  return setup_priority::BUS - 1.0f;
+}
+void Modbus::send(uint8_t address, uint8_t function, uint16_t start_address, uint16_t register_count) {
+  uint8_t frame[8];
+  frame[0] = address;
+  frame[1] = function;
+  frame[2] = start_address >> 8;
+  frame[3] = start_address >> 0;
+  frame[4] = register_count >> 8;
+  frame[5] = register_count >> 0;
+  auto crc = crc16(frame, 6);
+  frame[6] = crc >> 0;
+  frame[7] = crc >> 8;
+
+  this->write_array(frame, 8);
+}
+
+}  // namespace modbus
+}  // namespace esphome
diff --git a/esphome/components/modbus/modbus.h b/esphome/components/modbus/modbus.h
new file mode 100644
index 0000000000..b75de147b1
--- /dev/null
+++ b/esphome/components/modbus/modbus.h
@@ -0,0 +1,51 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/uart/uart.h"
+
+namespace esphome {
+namespace modbus {
+
+class ModbusDevice;
+
+class Modbus : public uart::UARTDevice, public Component {
+ public:
+  Modbus() = default;
+
+  void loop() override;
+
+  void dump_config() override;
+
+  void register_device(ModbusDevice *device) { this->devices_.push_back(device); }
+
+  float get_setup_priority() const override;
+
+  void send(uint8_t address, uint8_t function, uint16_t start_address, uint16_t register_count);
+
+ protected:
+  bool parse_modbus_byte_(uint8_t byte);
+
+  std::vector<uint8_t> rx_buffer_;
+  uint32_t last_modbus_byte_{0};
+  std::vector<ModbusDevice *> devices_;
+};
+
+class ModbusDevice {
+ public:
+  void set_parent(Modbus *parent) { parent_ = parent; }
+  void set_address(uint8_t address) { address_ = address; }
+  virtual void on_modbus_data(const std::vector<uint8_t> &data) = 0;
+
+  void send(uint8_t function, uint16_t start_address, uint16_t register_count) {
+    this->parent_->send(this->address_, function, start_address, register_count);
+  }
+
+ protected:
+  friend Modbus;
+
+  Modbus *parent_;
+  uint8_t address_;
+};
+
+}  // namespace modbus
+}  // namespace esphome
diff --git a/esphome/components/pmsx003/pmsx003.cpp b/esphome/components/pmsx003/pmsx003.cpp
index 548099a495..489442c637 100644
--- a/esphome/components/pmsx003/pmsx003.cpp
+++ b/esphome/components/pmsx003/pmsx003.cpp
@@ -169,6 +169,7 @@ void PMSX003Component::dump_config() {
   LOG_SENSOR("  ", "Temperature", this->temperature_sensor_);
   LOG_SENSOR("  ", "Humidity", this->humidity_sensor_);
   LOG_SENSOR("  ", "Formaldehyde", this->formaldehyde_sensor_);
+  this->check_uart_settings(9600);
 }
 
 }  // namespace pmsx003
diff --git a/esphome/components/pzem004t/__init__.py b/esphome/components/pzem004t/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/esphome/components/pzem004t/pzem004t.cpp b/esphome/components/pzem004t/pzem004t.cpp
new file mode 100644
index 0000000000..3f07e74f9b
--- /dev/null
+++ b/esphome/components/pzem004t/pzem004t.cpp
@@ -0,0 +1,103 @@
+#include "pzem004t.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace pzem004t {
+
+static const char *TAG = "pzem004t";
+
+void PZEM004T::loop() {
+  const uint32_t now = millis();
+  if (now - this->last_read_ > 500 && this->available()) {
+    while (this->available())
+      this->read();
+    this->last_read_ = now;
+  }
+
+  // PZEM004T packet size is 7 byte
+  while (this->available() >= 7) {
+    auto resp = *this->read_array<7>();
+    // packet format:
+    // 0: packet type
+    // 1-5: data
+    // 6: checksum (sum of other bytes)
+    // see https://github.com/olehs/PZEM004T
+    uint8_t sum = 0;
+    for (int i = 0; i < 6; i++)
+      sum += resp[i];
+
+    if (sum != resp[6]) {
+      ESP_LOGV(TAG, "PZEM004T invalid checksum! 0x%02X != 0x%02X", sum, resp[6]);
+      continue;
+    }
+
+    switch (resp[0]) {
+      case 0xA4: {  // Set Module Address Response
+        this->write_state_(READ_VOLTAGE);
+        break;
+      }
+      case 0xA0: {  // Voltage Response
+        uint16_t int_voltage = (uint16_t(resp[1]) << 8) | (uint16_t(resp[2]) << 0);
+        float voltage = int_voltage + (resp[3] / 10.0f);
+        if (this->voltage_sensor_ != nullptr)
+          this->voltage_sensor_->publish_state(voltage);
+        ESP_LOGD(TAG, "Got Voltage %.1f V", voltage);
+        this->write_state_(READ_CURRENT);
+        break;
+      }
+      case 0xA1: {  // Current Response
+        uint16_t int_current = (uint16_t(resp[1]) << 8) | (uint16_t(resp[2]) << 0);
+        float current = int_current + (resp[3] / 100.0f);
+        if (this->current_sensor_ != nullptr)
+          this->current_sensor_->publish_state(current);
+        ESP_LOGD(TAG, "Got Current %.2f A", current);
+        this->write_state_(READ_POWER);
+        break;
+      }
+      case 0xA2: {  // Active Power Response
+        uint16_t power = (uint16_t(resp[1]) << 8) | (uint16_t(resp[2]) << 0);
+        if (this->power_sensor_ != nullptr)
+          this->power_sensor_->publish_state(power);
+        ESP_LOGD(TAG, "Got Power %u W", power);
+        this->write_state_(DONE);
+        break;
+      }
+
+      case 0xA3:  // Energy Response
+      case 0xA5:  // Set Power Alarm Response
+      case 0xB0:  // Voltage Request
+      case 0xB1:  // Current Request
+      case 0xB2:  // Active Power Response
+      case 0xB3:  // Energy Request
+      case 0xB4:  // Set Module Address Request
+      case 0xB5:  // Set Power Alarm Request
+      default:
+        break;
+    }
+
+    this->last_read_ = now;
+  }
+}
+void PZEM004T::update() { this->write_state_(SET_ADDRESS); }
+void PZEM004T::write_state_(PZEM004T::PZEM004TReadState state) {
+  if (state == DONE) {
+    this->read_state_ = state;
+    return;
+  }
+  std::array<uint8_t, 7> data{};
+  data[0] = state;
+  data[1] = 192;
+  data[2] = 168;
+  data[3] = 1;
+  data[4] = 1;
+  data[5] = 0;
+  data[6] = 0;
+  for (int i = 0; i < 6; i++)
+    data[6] += data[i];
+
+  this->write_array(data);
+  this->read_state_ = state;
+}
+
+}  // namespace pzem004t
+}  // namespace esphome
diff --git a/esphome/components/pzem004t/pzem004t.h b/esphome/components/pzem004t/pzem004t.h
new file mode 100644
index 0000000000..7969efd78c
--- /dev/null
+++ b/esphome/components/pzem004t/pzem004t.h
@@ -0,0 +1,39 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/uart/uart.h"
+#include "esphome/components/sensor/sensor.h"
+
+namespace esphome {
+namespace pzem004t {
+
+class PZEM004T : public PollingComponent, public uart::UARTDevice {
+ public:
+  void set_voltage_sensor(sensor::Sensor *voltage_sensor) { voltage_sensor_ = voltage_sensor; }
+  void set_current_sensor(sensor::Sensor *current_sensor) { current_sensor_ = current_sensor; }
+  void set_power_sensor(sensor::Sensor *power_sensor) { power_sensor_ = power_sensor; }
+
+  void loop() override;
+
+  void update() override;
+
+ protected:
+  sensor::Sensor *voltage_sensor_;
+  sensor::Sensor *current_sensor_;
+  sensor::Sensor *power_sensor_;
+
+  enum PZEM004TReadState {
+    SET_ADDRESS = 0xB4,
+    READ_VOLTAGE = 0xB0,
+    READ_CURRENT = 0xB1,
+    READ_POWER = 0xB2,
+    DONE = 0x00,
+  } read_state_{DONE};
+
+  void write_state_(PZEM004TReadState state);
+
+  uint32_t last_read_{0};
+};
+
+}  // namespace pzem004t
+}  // namespace esphome
diff --git a/esphome/components/pzem004t/sensor.py b/esphome/components/pzem004t/sensor.py
new file mode 100644
index 0000000000..6e3628c5ec
--- /dev/null
+++ b/esphome/components/pzem004t/sensor.py
@@ -0,0 +1,37 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.components import sensor, uart
+from esphome.const import CONF_CURRENT, CONF_ID, CONF_POWER, CONF_VOLTAGE, \
+    UNIT_VOLT, ICON_FLASH, UNIT_AMPERE, UNIT_WATT
+
+DEPENDENCIES = ['uart']
+
+pzem004t_ns = cg.esphome_ns.namespace('pzem004t')
+PZEM004T = pzem004t_ns.class_('PZEM004T', cg.PollingComponent, uart.UARTDevice)
+
+CONFIG_SCHEMA = cv.Schema({
+    cv.GenerateID(): cv.declare_id(PZEM004T),
+
+    cv.Optional(CONF_VOLTAGE): sensor.sensor_schema(UNIT_VOLT, ICON_FLASH, 1),
+    cv.Optional(CONF_CURRENT): sensor.sensor_schema(UNIT_AMPERE, ICON_FLASH, 2),
+    cv.Optional(CONF_POWER): sensor.sensor_schema(UNIT_WATT, ICON_FLASH, 0),
+}).extend(cv.polling_component_schema('60s')).extend(uart.UART_DEVICE_SCHEMA)
+
+
+def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    yield cg.register_component(var, config)
+    yield uart.register_uart_device(var, config)
+
+    if CONF_VOLTAGE in config:
+        conf = config[CONF_VOLTAGE]
+        sens = yield sensor.new_sensor(conf)
+        cg.add(var.set_voltage_sensor(sens))
+    if CONF_CURRENT in config:
+        conf = config[CONF_CURRENT]
+        sens = yield sensor.new_sensor(conf)
+        cg.add(var.set_current_sensor(sens))
+    if CONF_POWER in config:
+        conf = config[CONF_POWER]
+        sens = yield sensor.new_sensor(conf)
+        cg.add(var.set_power_sensor(sens))
diff --git a/esphome/components/pzemac/__init__.py b/esphome/components/pzemac/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/esphome/components/pzemac/pzemac.cpp b/esphome/components/pzemac/pzemac.cpp
new file mode 100644
index 0000000000..1c3957dc09
--- /dev/null
+++ b/esphome/components/pzemac/pzemac.cpp
@@ -0,0 +1,62 @@
+#include "pzemac.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace pzemac {
+
+static const char *TAG = "pzemac";
+
+static const uint8_t PZEM_CMD_READ_IN_REGISTERS = 0x04;
+static const uint8_t PZEM_REGISTER_COUNT = 10;  // 10x 16-bit registers
+
+void PZEMAC::on_modbus_data(const std::vector<uint8_t> &data) {
+  if (data.size() < 20) {
+    ESP_LOGW(TAG, "Invalid size for PZEM AC!");
+    return;
+  }
+
+  // See https://github.com/esphome/feature-requests/issues/49#issuecomment-538636809
+  //  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
+  // 01 04 14 08 D1 00 6C 00 00 00 F4 00 00 00 26 00 00 01 F4 00 64 00 00 51 34
+  // Id Cc Sz Volt- Current---- Power------ Energy----- Frequ PFact Alarm Crc--
+
+  auto pzem_get_16bit = [&](size_t i) -> uint16_t {
+    return (uint16_t(data[i + 0]) << 8) | (uint16_t(data[i + 1]) << 0);
+  };
+  auto pzem_get_32bit = [&](size_t i) -> uint32_t {
+    return (uint32_t(pzem_get_16bit(i + 2)) << 16) | (uint32_t(pzem_get_16bit(i + 0)) << 0);
+  };
+
+  uint16_t raw_voltage = pzem_get_16bit(0);
+  float voltage = raw_voltage / 10.0f;  // max 6553.5 V
+
+  uint32_t raw_current = pzem_get_32bit(2);
+  float current = raw_current / 1000.0f;  // max 4294967.295 A
+
+  uint32_t raw_active_power = pzem_get_32bit(6);
+  float active_power = raw_active_power / 10.0f;  // max 429496729.5 W
+
+  uint16_t raw_frequency = pzem_get_16bit(14);
+  float frequency = raw_frequency / 10.0f;
+
+  uint16_t raw_power_factor = pzem_get_16bit(16);
+  float power_factor = raw_power_factor / 100.0f;
+
+  ESP_LOGD(TAG, "PZEM AC: V=%.1f V, I=%.3f A, P=%.1f W, F=%.1f Hz, PF=%.2f", voltage, current, active_power, frequency,
+           power_factor);
+  if (this->voltage_sensor_ != nullptr)
+    this->voltage_sensor_->publish_state(voltage);
+  if (this->current_sensor_ != nullptr)
+    this->current_sensor_->publish_state(current);
+  if (this->power_sensor_ != nullptr)
+    this->power_sensor_->publish_state(active_power);
+  if (this->frequency_sensor_ != nullptr)
+    this->frequency_sensor_->publish_state(frequency);
+  if (this->power_factor_sensor_ != nullptr)
+    this->power_factor_sensor_->publish_state(power_factor);
+}
+
+void PZEMAC::update() { this->send(PZEM_CMD_READ_IN_REGISTERS, 0, PZEM_REGISTER_COUNT); }
+
+}  // namespace pzemac
+}  // namespace esphome
diff --git a/esphome/components/pzemac/pzemac.h b/esphome/components/pzemac/pzemac.h
new file mode 100644
index 0000000000..0ba742fafe
--- /dev/null
+++ b/esphome/components/pzemac/pzemac.h
@@ -0,0 +1,31 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/sensor/sensor.h"
+#include "esphome/components/modbus/modbus.h"
+
+namespace esphome {
+namespace pzemac {
+
+class PZEMAC : public PollingComponent, public modbus::ModbusDevice {
+ public:
+  void set_voltage_sensor(sensor::Sensor *voltage_sensor) { voltage_sensor_ = voltage_sensor; }
+  void set_current_sensor(sensor::Sensor *current_sensor) { current_sensor_ = current_sensor; }
+  void set_power_sensor(sensor::Sensor *power_sensor) { power_sensor_ = power_sensor; }
+  void set_frequency_sensor(sensor::Sensor *frequency_sensor) { frequency_sensor_ = frequency_sensor; }
+  void set_power_factor_sensor(sensor::Sensor *power_factor_sensor) { power_factor_sensor_ = power_factor_sensor; }
+
+  void update() override;
+
+  void on_modbus_data(const std::vector<uint8_t> &data) override;
+
+ protected:
+  sensor::Sensor *voltage_sensor_;
+  sensor::Sensor *current_sensor_;
+  sensor::Sensor *power_sensor_;
+  sensor::Sensor *frequency_sensor_;
+  sensor::Sensor *power_factor_sensor_;
+};
+
+}  // namespace pzemac
+}  // namespace esphome
diff --git a/esphome/components/pzemac/sensor.py b/esphome/components/pzemac/sensor.py
new file mode 100644
index 0000000000..35d8069767
--- /dev/null
+++ b/esphome/components/pzemac/sensor.py
@@ -0,0 +1,47 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.components import sensor, modbus
+from esphome.const import CONF_CURRENT, CONF_ID, CONF_POWER, CONF_VOLTAGE, \
+    CONF_FREQUENCY, UNIT_VOLT, ICON_FLASH, UNIT_AMPERE, UNIT_WATT, UNIT_EMPTY, \
+    ICON_POWER, CONF_POWER_FACTOR, ICON_CURRENT_AC
+
+AUTO_LOAD = ['modbus']
+
+pzemac_ns = cg.esphome_ns.namespace('pzemac')
+PZEMAC = pzemac_ns.class_('PZEMAC', cg.PollingComponent, modbus.ModbusDevice)
+
+CONFIG_SCHEMA = cv.Schema({
+    cv.GenerateID(): cv.declare_id(PZEMAC),
+    cv.Optional(CONF_VOLTAGE): sensor.sensor_schema(UNIT_VOLT, ICON_FLASH, 1),
+    cv.Optional(CONF_CURRENT): sensor.sensor_schema(UNIT_AMPERE, ICON_CURRENT_AC, 3),
+    cv.Optional(CONF_POWER): sensor.sensor_schema(UNIT_WATT, ICON_POWER, 1),
+    cv.Optional(CONF_FREQUENCY): sensor.sensor_schema(UNIT_EMPTY, ICON_CURRENT_AC, 1),
+    cv.Optional(CONF_POWER_FACTOR): sensor.sensor_schema(UNIT_EMPTY, ICON_FLASH, 2),
+}).extend(cv.polling_component_schema('60s')).extend(modbus.modbus_device_schema(0x01))
+
+
+def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    yield cg.register_component(var, config)
+    yield modbus.register_modbus_device(var, config)
+
+    if CONF_VOLTAGE in config:
+        conf = config[CONF_VOLTAGE]
+        sens = yield sensor.new_sensor(conf)
+        cg.add(var.set_voltage_sensor(sens))
+    if CONF_CURRENT in config:
+        conf = config[CONF_CURRENT]
+        sens = yield sensor.new_sensor(conf)
+        cg.add(var.set_current_sensor(sens))
+    if CONF_POWER in config:
+        conf = config[CONF_POWER]
+        sens = yield sensor.new_sensor(conf)
+        cg.add(var.set_power_sensor(sens))
+    if CONF_FREQUENCY in config:
+        conf = config[CONF_FREQUENCY]
+        sens = yield sensor.new_sensor(conf)
+        cg.add(var.set_frequency_sensor(sens))
+    if CONF_POWER_FACTOR in config:
+        conf = config[CONF_POWER_FACTOR]
+        sens = yield sensor.new_sensor(conf)
+        cg.add(var.set_power_factor_sensor(sens))
diff --git a/esphome/components/pzemdc/__init__.py b/esphome/components/pzemdc/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/esphome/components/pzemdc/pzemdc.cpp b/esphome/components/pzemdc/pzemdc.cpp
new file mode 100644
index 0000000000..c85d35106d
--- /dev/null
+++ b/esphome/components/pzemdc/pzemdc.cpp
@@ -0,0 +1,52 @@
+#include "pzemdc.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace pzemdc {
+
+static const char *TAG = "pzemdc";
+
+static const uint8_t PZEM_CMD_READ_IN_REGISTERS = 0x04;
+static const uint8_t PZEM_REGISTER_COUNT = 10;  // 10x 16-bit registers
+
+void PZEMDC::on_modbus_data(const std::vector<uint8_t> &data) {
+  if (data.size() < 16) {
+    ESP_LOGW(TAG, "Invalid size for PZEM DC!");
+    return;
+  }
+
+  // See https://github.com/esphome/feature-requests/issues/49#issuecomment-538636809
+  //           0     1     2     3     4     5     6     7           = ModBus register
+  //  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20  = Buffer index
+  // 01 04 10 05 40 00 0A 00 0D 00 00 00 02 00 00 00 00 00 00 D6 29
+  // Id Cc Sz Volt- Curre Power------ Energy----- HiAlm LoAlm Crc--
+
+  auto pzem_get_16bit = [&](size_t i) -> uint16_t {
+    return (uint16_t(data[i + 0]) << 8) | (uint16_t(data[i + 1]) << 0);
+  };
+  auto pzem_get_32bit = [&](size_t i) -> uint32_t {
+    return (uint32_t(pzem_get_16bit(i + 2)) << 16) | (uint32_t(pzem_get_16bit(i + 0)) << 0);
+  };
+
+  uint16_t raw_voltage = pzem_get_16bit(0);
+  float voltage = raw_voltage / 100.0f;  // max 655.35 V
+
+  uint16_t raw_current = pzem_get_16bit(2);
+  float current = raw_current / 100.0f;  // max 655.35 A
+
+  uint32_t raw_power = pzem_get_32bit(4);
+  float power = raw_power / 10.0f;  // max 429496729.5 W
+
+  ESP_LOGD(TAG, "PZEM DC: V=%.1f V, I=%.3f A, P=%.1f W", voltage, current, power);
+  if (this->voltage_sensor_ != nullptr)
+    this->voltage_sensor_->publish_state(voltage);
+  if (this->current_sensor_ != nullptr)
+    this->current_sensor_->publish_state(current);
+  if (this->power_sensor_ != nullptr)
+    this->power_sensor_->publish_state(power);
+}
+
+void PZEMDC::update() { this->send(PZEM_CMD_READ_IN_REGISTERS, 0, 8); }
+
+}  // namespace pzemdc
+}  // namespace esphome
diff --git a/esphome/components/pzemdc/pzemdc.h b/esphome/components/pzemdc/pzemdc.h
new file mode 100644
index 0000000000..e19203dc21
--- /dev/null
+++ b/esphome/components/pzemdc/pzemdc.h
@@ -0,0 +1,31 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/sensor/sensor.h"
+#include "esphome/components/modbus/modbus.h"
+
+namespace esphome {
+namespace pzemdc {
+
+class PZEMDC : public PollingComponent, public modbus::ModbusDevice {
+ public:
+  void set_voltage_sensor(sensor::Sensor *voltage_sensor) { voltage_sensor_ = voltage_sensor; }
+  void set_current_sensor(sensor::Sensor *current_sensor) { current_sensor_ = current_sensor; }
+  void set_power_sensor(sensor::Sensor *power_sensor) { power_sensor_ = power_sensor; }
+  void set_frequency_sensor(sensor::Sensor *frequency_sensor) { frequency_sensor_ = frequency_sensor; }
+  void set_powerfactor_sensor(sensor::Sensor *powerfactor_sensor) { power_factor_sensor_ = powerfactor_sensor; }
+
+  void update() override;
+
+  void on_modbus_data(const std::vector<uint8_t> &data) override;
+
+ protected:
+  sensor::Sensor *voltage_sensor_;
+  sensor::Sensor *current_sensor_;
+  sensor::Sensor *power_sensor_;
+  sensor::Sensor *frequency_sensor_;
+  sensor::Sensor *power_factor_sensor_;
+};
+
+}  // namespace pzemdc
+}  // namespace esphome
diff --git a/esphome/components/pzemdc/sensor.py b/esphome/components/pzemdc/sensor.py
new file mode 100644
index 0000000000..8c6fd08868
--- /dev/null
+++ b/esphome/components/pzemdc/sensor.py
@@ -0,0 +1,36 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.components import sensor, modbus
+from esphome.const import CONF_CURRENT, CONF_ID, CONF_POWER, CONF_VOLTAGE, \
+    UNIT_VOLT, ICON_FLASH, UNIT_AMPERE, UNIT_WATT, ICON_POWER, ICON_CURRENT_AC
+
+AUTO_LOAD = ['modbus']
+
+pzemdc_ns = cg.esphome_ns.namespace('pzemdc')
+PZEMDC = pzemdc_ns.class_('PZEMDC', cg.PollingComponent, modbus.ModbusDevice)
+
+CONFIG_SCHEMA = cv.Schema({
+    cv.GenerateID(): cv.declare_id(PZEMDC),
+    cv.Optional(CONF_VOLTAGE): sensor.sensor_schema(UNIT_VOLT, ICON_FLASH, 1),
+    cv.Optional(CONF_CURRENT): sensor.sensor_schema(UNIT_AMPERE, ICON_CURRENT_AC, 3),
+    cv.Optional(CONF_POWER): sensor.sensor_schema(UNIT_WATT, ICON_POWER, 1),
+}).extend(cv.polling_component_schema('60s')).extend(modbus.modbus_device_schema(0x01))
+
+
+def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    yield cg.register_component(var, config)
+    yield modbus.register_modbus_device(var, config)
+
+    if CONF_VOLTAGE in config:
+        conf = config[CONF_VOLTAGE]
+        sens = yield sensor.new_sensor(conf)
+        cg.add(var.set_voltage_sensor(sens))
+    if CONF_CURRENT in config:
+        conf = config[CONF_CURRENT]
+        sens = yield sensor.new_sensor(conf)
+        cg.add(var.set_current_sensor(sens))
+    if CONF_POWER in config:
+        conf = config[CONF_POWER]
+        sens = yield sensor.new_sensor(conf)
+        cg.add(var.set_power_sensor(sens))
diff --git a/esphome/components/sds011/sds011.cpp b/esphome/components/sds011/sds011.cpp
index 6ca414c55d..1a5be0adc3 100644
--- a/esphome/components/sds011/sds011.cpp
+++ b/esphome/components/sds011/sds011.cpp
@@ -56,6 +56,7 @@ void SDS011Component::dump_config() {
   ESP_LOGCONFIG(TAG, "  RX-only mode: %s", ONOFF(this->rx_mode_only_));
   LOG_SENSOR("  ", "PM2.5", this->pm_2_5_sensor_);
   LOG_SENSOR("  ", "PM10.0", this->pm_10_0_sensor_);
+  this->check_uart_settings(9600);
 }
 
 void SDS011Component::loop() {
diff --git a/esphome/components/senseair/senseair.cpp b/esphome/components/senseair/senseair.cpp
index 96f456282f..8b41a441ad 100644
--- a/esphome/components/senseair/senseair.cpp
+++ b/esphome/components/senseair/senseair.cpp
@@ -73,6 +73,7 @@ bool SenseAirComponent::senseair_write_command_(const uint8_t *command, uint8_t
 void SenseAirComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "SenseAir:");
   LOG_SENSOR("  ", "CO2", this->co2_sensor_);
+  this->check_uart_settings(9600);
 }
 
 }  // namespace senseair
diff --git a/esphome/components/tuya/tuya.cpp b/esphome/components/tuya/tuya.cpp
index ae3e7eed43..4efcf08fe6 100644
--- a/esphome/components/tuya/tuya.cpp
+++ b/esphome/components/tuya/tuya.cpp
@@ -36,6 +36,7 @@ void Tuya::dump_config() {
     else
       ESP_LOGCONFIG(TAG, "  Datapoint %d: unknown", info.id);
   }
+  this->check_uart_settings(9600);
 }
 
 bool Tuya::validate_message_() {
diff --git a/esphome/components/uart/__init__.py b/esphome/components/uart/__init__.py
index 110bd64c81..2511cf28b1 100644
--- a/esphome/components/uart/__init__.py
+++ b/esphome/components/uart/__init__.py
@@ -29,11 +29,13 @@ def validate_rx_pin(value):
     return value
 
 
+CONF_STOP_BITS = 'stop_bits'
 CONFIG_SCHEMA = cv.All(cv.Schema({
     cv.GenerateID(): cv.declare_id(UARTComponent),
     cv.Required(CONF_BAUD_RATE): cv.int_range(min=1),
     cv.Optional(CONF_TX_PIN): pins.output_pin,
     cv.Optional(CONF_RX_PIN): validate_rx_pin,
+    cv.Optional(CONF_STOP_BITS, default=1): cv.one_of(1, 2, int=True),
 }).extend(cv.COMPONENT_SCHEMA), cv.has_at_least_one_key(CONF_TX_PIN, CONF_RX_PIN))
 
 
@@ -48,6 +50,7 @@ def to_code(config):
         cg.add(var.set_tx_pin(config[CONF_TX_PIN]))
     if CONF_RX_PIN in config:
         cg.add(var.set_rx_pin(config[CONF_RX_PIN]))
+    cg.add(var.set_stop_bits(config[CONF_STOP_BITS]))
 
 
 # A schema to use for all UART devices, all UART integrations must extend this!
diff --git a/esphome/components/uart/uart.cpp b/esphome/components/uart/uart.cpp
index 83ae81490e..fd27a8f897 100644
--- a/esphome/components/uart/uart.cpp
+++ b/esphome/components/uart/uart.cpp
@@ -25,7 +25,10 @@ void UARTComponent::setup() {
   }
   int8_t tx = this->tx_pin_.has_value() ? *this->tx_pin_ : -1;
   int8_t rx = this->rx_pin_.has_value() ? *this->rx_pin_ : -1;
-  this->hw_serial_->begin(this->baud_rate_, SERIAL_8N1, rx, tx);
+  uint32_t config = SERIAL_8N1;
+  if (this->stop_bits_ == 2)
+    config = SERIAL_8N2;
+  this->hw_serial_->begin(this->baud_rate_, config, rx, tx);
 }
 
 void UARTComponent::dump_config() {
@@ -37,6 +40,7 @@ void UARTComponent::dump_config() {
     ESP_LOGCONFIG(TAG, "  RX Pin: GPIO%d", *this->rx_pin_);
   }
   ESP_LOGCONFIG(TAG, "  Baud Rate: %u baud", this->baud_rate_);
+  ESP_LOGCONFIG(TAG, "  Stop bits: %u", this->stop_bits_);
 }
 
 void UARTComponent::write_byte(uint8_t data) {
@@ -102,21 +106,27 @@ void UARTComponent::setup() {
   // Use Arduino HardwareSerial UARTs if all used pins match the ones
   // preconfigured by the platform. For example if RX disabled but TX pin
   // is 1 we still want to use Serial.
+  uint32_t mode = UART_NB_BIT_8 | UART_PARITY_NONE;
+  if (this->stop_bits_ == 1)
+    mode |= UART_NB_STOP_BIT_1;
+  else
+    mode |= UART_NB_STOP_BIT_2;
+  SerialConfig config = static_cast<SerialConfig>(mode);
   if (this->tx_pin_.value_or(1) == 1 && this->rx_pin_.value_or(3) == 3) {
     this->hw_serial_ = &Serial;
-    this->hw_serial_->begin(this->baud_rate_);
+    this->hw_serial_->begin(this->baud_rate_, config);
   } else if (this->tx_pin_.value_or(15) == 15 && this->rx_pin_.value_or(13) == 13) {
     this->hw_serial_ = &Serial;
-    this->hw_serial_->begin(this->baud_rate_);
+    this->hw_serial_->begin(this->baud_rate_, config);
     this->hw_serial_->swap();
   } else if (this->tx_pin_.value_or(2) == 2 && this->rx_pin_.value_or(8) == 8) {
     this->hw_serial_ = &Serial1;
-    this->hw_serial_->begin(this->baud_rate_);
+    this->hw_serial_->begin(this->baud_rate_, config);
   } else {
     this->sw_serial_ = new ESP8266SoftwareSerial();
     int8_t tx = this->tx_pin_.has_value() ? *this->tx_pin_ : -1;
     int8_t rx = this->rx_pin_.has_value() ? *this->rx_pin_ : -1;
-    this->sw_serial_->setup(tx, rx, this->baud_rate_);
+    this->sw_serial_->setup(tx, rx, this->baud_rate_, this->stop_bits_);
   }
 }
 
@@ -129,6 +139,7 @@ void UARTComponent::dump_config() {
     ESP_LOGCONFIG(TAG, "  RX Pin: GPIO%d", *this->rx_pin_);
   }
   ESP_LOGCONFIG(TAG, "  Baud Rate: %u baud", this->baud_rate_);
+  ESP_LOGCONFIG(TAG, "  Stop bits: %u", this->stop_bits_);
   if (this->hw_serial_ != nullptr) {
     ESP_LOGCONFIG(TAG, "  Using hardware serial interface.");
   } else {
@@ -231,7 +242,7 @@ void UARTComponent::flush() {
   }
 }
 
-void ESP8266SoftwareSerial::setup(int8_t tx_pin, int8_t rx_pin, uint32_t baud_rate) {
+void ESP8266SoftwareSerial::setup(int8_t tx_pin, int8_t rx_pin, uint32_t baud_rate, uint8_t stop_bits) {
   this->bit_time_ = F_CPU / baud_rate;
   if (tx_pin != -1) {
     auto pin = GPIOPin(tx_pin, OUTPUT);
@@ -246,6 +257,7 @@ void ESP8266SoftwareSerial::setup(int8_t tx_pin, int8_t rx_pin, uint32_t baud_ra
     this->rx_buffer_ = new uint8_t[this->rx_buffer_size_];
     pin.attach_interrupt(ESP8266SoftwareSerial::gpio_intr, this, FALLING);
   }
+  this->stop_bits_ = stop_bits;
 }
 void ICACHE_RAM_ATTR ESP8266SoftwareSerial::gpio_intr(ESP8266SoftwareSerial *arg) {
   uint32_t wait = arg->bit_time_ + arg->bit_time_ / 3 - 500;
@@ -262,6 +274,8 @@ void ICACHE_RAM_ATTR ESP8266SoftwareSerial::gpio_intr(ESP8266SoftwareSerial *arg
   rec |= arg->read_bit_(&wait, start) << 7;
   // Stop bit
   arg->wait_(&wait, start);
+  if (arg->stop_bits_ == 2)
+    arg->wait_(&wait, start);
 
   arg->rx_buffer_[arg->rx_in_pos_] = rec;
   arg->rx_in_pos_ = (arg->rx_in_pos_ + 1) % arg->rx_buffer_size_;
@@ -289,6 +303,8 @@ void ICACHE_RAM_ATTR HOT ESP8266SoftwareSerial::write_byte(uint8_t data) {
   this->write_bit_(data & (1 << 7), &wait, start);
   // Stop bit
   this->write_bit_(true, &wait, start);
+  if (this->stop_bits_ == 2)
+    this->wait_(&wait, start);
   enable_interrupts();
 }
 void ICACHE_RAM_ATTR ESP8266SoftwareSerial::wait_(uint32_t *wait, const uint32_t &start) {
@@ -344,5 +360,16 @@ int UARTComponent::peek() {
   return data;
 }
 
+void UARTDevice::check_uart_settings(uint32_t baud_rate, uint8_t stop_bits) {
+  if (this->parent_->baud_rate_ != baud_rate) {
+    ESP_LOGE(TAG, "  Invalid baud_rate: Integration requested baud_rate %u but you have %u!", baud_rate,
+             this->parent_->baud_rate_);
+  }
+  if (this->parent_->stop_bits_ != stop_bits) {
+    ESP_LOGE(TAG, "  Invalid stop bits: Integration requested stop_bits %u but you have %u!", stop_bits,
+             this->parent_->stop_bits_);
+  }
+}
+
 }  // namespace uart
 }  // namespace esphome
diff --git a/esphome/components/uart/uart.h b/esphome/components/uart/uart.h
index 3b347c1ff7..0e92fed0dc 100644
--- a/esphome/components/uart/uart.h
+++ b/esphome/components/uart/uart.h
@@ -10,7 +10,7 @@ namespace uart {
 #ifdef ARDUINO_ARCH_ESP8266
 class ESP8266SoftwareSerial {
  public:
-  void setup(int8_t tx_pin, int8_t rx_pin, uint32_t baud_rate);
+  void setup(int8_t tx_pin, int8_t rx_pin, uint32_t baud_rate, uint8_t stop_bits);
 
   uint8_t read_byte();
   uint8_t peek_byte();
@@ -33,6 +33,7 @@ class ESP8266SoftwareSerial {
   size_t rx_buffer_size_{512};
   volatile size_t rx_in_pos_{0};
   size_t rx_out_pos_{0};
+  uint8_t stop_bits_;
   ISRInternalGPIOPin *tx_pin_{nullptr};
   ISRInternalGPIOPin *rx_pin_{nullptr};
 };
@@ -72,9 +73,11 @@ class UARTComponent : public Component, public Stream {
 
   void set_tx_pin(uint8_t tx_pin) { this->tx_pin_ = tx_pin; }
   void set_rx_pin(uint8_t rx_pin) { this->rx_pin_ = rx_pin; }
+  void set_stop_bits(uint8_t stop_bits) { this->stop_bits_ = stop_bits; }
 
  protected:
   bool check_read_timeout_(size_t len = 1);
+  friend class UARTDevice;
 
   HardwareSerial *hw_serial_{nullptr};
 #ifdef ARDUINO_ARCH_ESP8266
@@ -83,6 +86,7 @@ class UARTComponent : public Component, public Stream {
   optional<uint8_t> tx_pin_;
   optional<uint8_t> rx_pin_;
   uint32_t baud_rate_;
+  uint8_t stop_bits_;
 };
 
 #ifdef ARDUINO_ARCH_ESP32
@@ -100,6 +104,9 @@ class UARTDevice : public Stream {
 
   void write_array(const uint8_t *data, size_t len) { this->parent_->write_array(data, len); }
   void write_array(const std::vector<uint8_t> &data) { this->parent_->write_array(data); }
+  template<size_t N> void write_array(const std::array<uint8_t, N> &data) {
+    this->parent_->write_array(data.data(), data.size());
+  }
 
   void write_str(const char *str) { this->parent_->write_str(str); }
 
@@ -107,6 +114,13 @@ class UARTDevice : public Stream {
   bool peek_byte(uint8_t *data) { return this->parent_->peek_byte(data); }
 
   bool read_array(uint8_t *data, size_t len) { return this->parent_->read_array(data, len); }
+  template<size_t N> optional<std::array<uint8_t, N>> read_array() {  // NOLINT
+    std::array<uint8_t, N> res;
+    if (!this->read_array(res.data(), N)) {
+      return {};
+    }
+    return res;
+  }
 
   int available() override { return this->parent_->available(); }
 
@@ -116,6 +130,9 @@ class UARTDevice : public Stream {
   int read() override { return this->parent_->read(); }
   int peek() override { return this->parent_->peek(); }
 
+  /// Check that the configuration of the UART bus matches the provided values and otherwise print a warning
+  void check_uart_settings(uint32_t baud_rate, uint8_t stop_bits = 1);
+
  protected:
   UARTComponent *parent_{nullptr};
 };
diff --git a/esphome/const.py b/esphome/const.py
index b595bdf629..163b526b32 100644
--- a/esphome/const.py
+++ b/esphome/const.py
@@ -323,6 +323,7 @@ CONF_PM_2_5 = 'pm_2_5'
 CONF_PORT = 'port'
 CONF_POSITION = 'position'
 CONF_POWER = 'power'
+CONF_POWER_FACTOR = 'power_factor'
 CONF_POWER_ON_VALUE = 'power_on_value'
 CONF_POWER_SAVE_MODE = 'power_save_mode'
 CONF_POWER_SUPPLY = 'power_supply'
@@ -479,6 +480,7 @@ ICON_BRIEFCASE_DOWNLOAD = 'mdi:briefcase-download'
 ICON_BRIGHTNESS_5 = 'mdi:brightness-5'
 ICON_CHEMICAL_WEAPON = 'mdi:chemical-weapon'
 ICON_CHECK_CIRCLE_OUTLINE = 'mdi:check-circle-outline'
+ICON_CURRENT_AC = 'mdi:current-ac'
 ICON_EMPTY = ''
 ICON_FLASH = 'mdi:flash'
 ICON_FLOWER = 'mdi:flower'
diff --git a/tests/test3.yaml b/tests/test3.yaml
index f3e530f07a..d1596c8f41 100644
--- a/tests/test3.yaml
+++ b/tests/test3.yaml
@@ -291,6 +291,31 @@ sensor:
       name: ADE7953 Active Power A
     active_power_b:
       name: ADE7953 Active Power B
+  - platform: pzem004t
+    voltage:
+      name: "PZEM00T Voltage"
+    current:
+      name: "PZEM004T Current"
+    power:
+      name: "PZEM004T Power"
+  - platform: pzemac
+    voltage:
+      name: "PZEMAC Voltage"
+    current:
+      name: "PZEMAC Current"
+    power:
+      name: "PZEMAC Power"
+    frequency:
+      name: "PZEMAC Frequency"
+    power_factor:
+      name: "PZEMAC Power Factor"
+  - platform: pzemdc
+    voltage:
+      name: "PZEMDC Voltage"
+    current:
+      name: "PZEMDC Current"
+    power:
+      name: "PZEMDC Power"
 
 time:
 - platform: homeassistant