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Renesas Electronics Corporation

Mid-Range Thermostat

Overview

Description

Mid-range thermostat systems build upon base thermostat systems with a cost-optimized UI, simplified voice control, and integrated sensors that switch relays for direct load control in an HVAC system. These systems then transmit measurement data to peer devices, such as a central thermostat and/or an outdoor unit.

This mid-range thermostat system can be leveraged for a wide range of needs—whether essential, enhanced, expanded, or extended. It comes in multiple variants, offering a wide range of functionalities and capabilities depending on the end application, to deliver scalable, smart, and sensor‑integrated systems for easy setup, control, and communication. Integrated Wi‑Fi® and Bluetooth® connect seamlessly to mobile apps and smart home ecosystems, enabling remote control and scheduling, while onboard sensors such as humidity and occupancy detection provide more accurate environmental awareness to optimize HVAC operation.

System Benefits:

  • Wi‑Fi 6 and Bluetooth connectivity enable remote monitoring, OTA updates, and smart home integration.
  • Easy installation and configuration via Bluetooth Low Energy (LE) and NFC eliminate the need for additional communications wiring by enabling wireless communication with other thermostats, sensors, and actuators through Wi‑Fi and Bluetooth LE.
  • Flexible HMI options—from simple voice command recognition and LCD visualization of critical information to sleek capacitive touch controls—enable intuitive, modern, and hands‑free user interaction.
  • Integrated sensors for temperature, humidity, and air quality enable precise environmental control through relay‑based load switching.
  • GreenPAK™ devices provide ultra‑low power latching relay control, reducing energy consumption while ensuring reliable HVAC switching.

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Essential Thermostat with Core Functionality

WS151-1: WEBLine.226Line Arrow.171Bridge Rectifier.184Sheet.3Sheet.4Sheet.5Sheet.6Sheet.7Sheet.8Sheet.9Sheet.10Sheet.11Sheet.12Sheet.13Sheet.14Sheet.15Sheet.16Sheet.17Sheet.18LineConnector 1.160Line ArrowConnector 1.160.23Connector ArrowEnableEnableEnable24VAC24VAC24VAC5V5V5VGroundSheet.33Sheet.34Battery 1-CellSheet.36Sheet.37Line 1pt.1552Line 1pt.1583Line.40Connector Arrow.41Line Arrow.42VSYSVSYSVSYSBi-directionalAntennaSheet.56Sheet.57Sheet.58Sheet.59Sheet.60Line.83Line Arrow.84VSYSVSYSVSYSTouch KeySheet.119Sheet.120Sheet.121Sheet.122Sheet.123Sheet.124Sheet.125Sheet.126Sheet.127Line Arrow.128Touch InterfaceTouch InterfaceTouch InterfaceLCD/LED Segment DisplaySheet.132Sheet.133Sheet.134Sheet.135Sheet.136Sheet.137Sheet.138Sheet.139Sheet.140Sheet.141Sheet.142Sheet.143Sheet.144Sheet.145Sheet.146Sheet.147Sheet.148Sheet.149Sheet.150Sheet.151Sheet.152Sheet.153Sheet.154Sheet.155Sheet.156Sheet.157Sheet.158Sheet.159Sheet.160ONONONOFFOFFOFFSheet.163Sheet.164Sheet.165Sheet.166Sheet.167Sheet.168Sheet.169Sheet.170VSYSVSYSVSYSLine Arrow.173LCD DisplayLCD DisplayLCD DisplayTemperature & Humidity SensorTemperature & Humidity SensorTemperature & Humidity SensorIAQ SensorIAQ SensorIAQ SensorBi-directional.178Connected signals arrowConnected signals arrow.180Connected signals arrow.181Line.210WS151-1WS151-1WS151-1Battery ChargerBattery ChargerBattery ChargerBuck-BoostBuck-BoostBuck-BoostWireless ConnectivityWireless ConnectivityWireless ConnectivityCentral ThermostatCentral ThermostatCentral ThermostatAntenna.220Sheet.230Sheet.231Sheet.232Sheet.233Sheet.234Line Bi-directional Dotted.236Wireless Connectivity (Wi-Fi or Bluetooth LE) or Wired Connectivity (RS-485, CAN, Ethernet)Wireless Connectivity (Wi-Fi or Bluetooth LE) or Wired Connec...Wireless Connectivity (Wi-Fi or Bluetooth LE) or Wired Connectivity (RS-485, CAN, Ethernet)Line Bi-directional Dotted.238Sheet.284CrystalSheet.286Sheet.287Sheet.288Sheet.289Sheet.290Sheet.291Sheet.292Line.69Line.7027.12MHz27.12MHz27.12MHzLine Bi-directional DottedNFC CoilNFC CoilNFC CoilNFC CoilSheet.299Transformer.324Line.841Line.842Sheet.303Inductor.300Sheet.305Sheet.306Sheet.307Line.103Line.104NFC ReaderNFC ReaderNFC ReaderVSYSVSYSVSYSLine Arrow.206Connector Arrow.315Connector Arrow.201Line Arrow.186Op AmpOp AmpOp AmpMicrophoneSheet.408Sheet.409Keyword detection & voice controlKeyword Detection & Voice ControlKeyword Detection & Voice ControlVSYSVSYSVSYSLine Arrow.203Line Arrow.205Line Arrow.213HVAC ControlHVAC ControlHVAC ControlRelay Control: GreenPAKRelay Control: GreenPAKRelay Control: GreenPAKLatching RelaysLatching RelaysLatching RelaysLine.214PIR Motion SensorPIR Motion SensorPIR Motion Sensor VSYSVSYSVSYSLine Arrow.194 VSYSVSYSVSYSLine Arrow.196Line Arrow.197Sheet.448 Comparator & Op AmpComparator & Op AmpComparator & Op AmpOp Amp.205PeripheralOp Amp ComparatorSheet.433Sheet.434DriverSheet.436Sheet.437Sheet.438Op Amp.214PeripheralOp Amp ComparatorSheet.442Sheet.443DriverSheet.445Sheet.446Sheet.447Sheet.449MCUMCUMCU GPIOGPIOGPIOUARTUARTUARTCTSUCTSUCTSUSLCDCSLCDCSLCDCI2CI2CI2CSPISPISPIGPIOGPIOGPIOGPIOGPIOGPIOADCADCADCBuck RegulatorBuck RegulatorBuck Regulator
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Enhanced Thermostat with Higher Display Resolution

WS151-2: WEBLine Arrow.197Line.83Connector Arrow.201Line Arrow.186Line Arrow.244Line Arrow.245Bridge Rectifier.184Sheet.7Sheet.8Sheet.9Sheet.10Sheet.11Sheet.12Sheet.13Sheet.14Sheet.15Sheet.16Sheet.17Sheet.18Sheet.19Sheet.20Sheet.21Sheet.22LineConnector 1.160Line ArrowConnector 1.2324VAC24VAC24VACLine Arrow.42VSYSVSYSVSYSBi-directionalAntennaSheet.32Sheet.33Sheet.34Sheet.35Sheet.36Wireless ConnectivityWireless ConnectivityWireless ConnectivityLine Arrow.84VSYSVSYSVSYSVSYSVSYSVSYSTemperature & Humidity SensorTemperature & Humidity SensorTemperature & Humidity SensorIAQ SensorIAQ SensorIAQ SensorConnected signals arrow.181MicrophoneSheet.47Sheet.48Keyword detection & voice controlKeyword Detection & Voice ControlKeyword Detection & Voice ControlVSYSVSYSVSYSLine Arrow.203Line Arrow.205Line.210Line Arrow.213HVAC ControlHVAC ControlHVAC ControlWS151-2WS151-2WS151-2LCD (TFT-LCD)Block.120TFT LCD, OLED, or MIPI DisplayTFT LCD, OLED, or MIPI DisplayTFT LCD, OLED, or MIPI DisplayLCD (TFT-LCD).231Sheet.70Sheet.71Sheet.72Line Bi-directionalTouch InterfaceTouch InterfaceTouch InterfaceLCD DriverLCD DriverLCD DriverBacklightBacklightBacklightConnector ArrowLine Arrow.252VSYSVSYSVSYSBi-directional.257Connector dotted arrowConnector 1.259Relay Control: GreenPAKRelay Control: GreenPAKRelay Control: GreenPAKLatching RelaysLatching RelaysLatching RelaysAntenna.220Sheet.99Sheet.100Sheet.101Sheet.102Sheet.103Line.226Line Bi-directional Dotted.227Line Bi-directional DottedWireless Connectivity (Wi-Fi or Bluetooth LE) or Wired Connectivity (RS-485, CAN, Ethernet)Wireless Connectivity (Wi-Fi or Bluetooth LE) or Wired Connec...Wireless Connectivity (Wi-Fi or Bluetooth LE) or Wired Connectivity (RS-485, CAN, Ethernet)Central ThermostatCentral ThermostatCentral ThermostatLine.214PIR Motion SensorPIR Motion SensorPIR Motion SensorSheet.143CrystalSheet.145Sheet.146Sheet.147Sheet.148Sheet.149Sheet.150Sheet.151Line.69Line.7027.12MHz27.12MHz27.12MHzLine Bi-directional Dotted.155NFC CoilNFC CoilNFC CoilNFC CoilSheet.158Transformer.324Line.841Line.842Sheet.162Inductor.300Sheet.164Sheet.165Sheet.166Line.103Line.104 VSYSVSYSVSYSLine Arrow.206 VSYSVSYSVSYSLine Arrow.194 VSYSVSYSVSYSLine Arrow.196Buck RegulatorBuck RegulatorBuck RegulatorNFC ReaderNFC ReaderNFC ReaderOp AmpOp AmpOp AmpSheet.223 Comparator & Op AmpComparator & Op AmpComparator & Op AmpOp Amp.205PeripheralOp Amp ComparatorSheet.208Sheet.209DriverSheet.211Sheet.212Sheet.213Op Amp.214PeripheralOp Amp ComparatorSheet.217Sheet.218DriverSheet.220Sheet.221Sheet.222Sheet.224MCUMCUMCUUARTUARTUARTI2CI2CI2CGPIOGPIOGPIOGPIOGPIOGPIOADCADCADC I2CI2CI2CDisplay I/FDisplay I/FDisplay I/FPWMPWMPWM SPISPISPI
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Expanded Thermostat with Scalable Smart Features

WS151-3: WEBLine Arrow.171Connector Arrow.233Line.4Sheet.5CrystalSheet.7Sheet.8Sheet.9Sheet.10Sheet.11Sheet.12Sheet.13Line.69Line.7040MHz40MHz40MHzSheet.17CrystalSheet.19Sheet.20Sheet.21Sheet.22Sheet.23Sheet.24Sheet.25Line.69Line.7032MHz32MHz32MHzSheet.29CrystalSheet.31Sheet.32Sheet.33Sheet.34Sheet.35Sheet.36Sheet.37Line.69Line.7027.12MHz27.12MHz27.12MHzBridge Rectifier.184Sheet.42Sheet.43Sheet.44Sheet.45Sheet.46Sheet.47Sheet.48Sheet.49Sheet.50Sheet.51Sheet.52Sheet.53Sheet.54Sheet.55Sheet.56Sheet.57LineConnector 1.160Line ArrowConnector 1.2324VAC24VAC24VACGroundSheet.64Sheet.65Battery 1-CellSheet.67Sheet.68Line 1pt.1552Line 1pt.1583Line.40Line Bi-directional DottedNFC CoilNFC CoilNFC CoilNFC CoilSheet.75Transformer.324Line.841Line.842Sheet.79Inductor.300Sheet.81Sheet.82Sheet.83Line.103Line.104NFC ReaderNFC ReaderNFC ReaderTemperature & Humidity SensorTemperature & Humidity SensorTemperature & Humidity SensorIAQ SensorIAQ SensorIAQ SensorBi-directional.178Connected signals arrowConnected signals arrow.181WS151-3WS151-3WS151-3VSYSVSYSVSYSLine Arrow.206Touch KeySheet.115Sheet.116Sheet.117Sheet.118Sheet.119Sheet.120Sheet.121Sheet.122Sheet.123Line Arrow.128Touch InterfaceTouch InterfaceTouch InterfaceLCD/LED Segment DisplaySheet.127Sheet.128Sheet.129Sheet.130Sheet.131Sheet.132Sheet.133Sheet.134Sheet.135Sheet.136Sheet.137Sheet.138Sheet.139Sheet.140Sheet.141Sheet.142Sheet.143Sheet.144Sheet.145Sheet.146Sheet.147Sheet.148Sheet.149Sheet.150Sheet.151Sheet.152Sheet.153Sheet.154Sheet.155ONONONOFFOFFOFFSheet.158Sheet.159Sheet.160Sheet.161Sheet.162Sheet.163Sheet.164Sheet.165VSYSVSYSVSYSLine Arrow.173Segment LCD DisplaySegment LCD DisplaySegment LCD DisplayVSYSVSYSVSYSConnector Arrow.2092x AA Batteries2x AA Batteries2x AA BatteriesConnector ArrowConnector Arrow.214CircleCircle.212VSYSVSYSVSYS3.3V3.3V3.3V3.3V3.3V3.3VConnector Arrow.218Connected signals arrow.219AntennaSheet.182Sheet.183Sheet.184Sheet.185Sheet.186Bi-directionalPSRAMPSRAMPSRAMBi-directional.236SPI NOR FlashSPI NOR FlashSPI NOR FlashBi-directional.239Buck RegulatorBuck RegulatorBuck RegulatorBuck-BoostBuck-BoostBuck-BoostORing SwitchORing SwitchORing SwitchSheet.215MCUMCUMCUCTSUCTSUCTSUSLCDCSLCDCSLCDCUARTUARTUARTGPIOGPIOGPIOAntenna.220Sheet.222Sheet.223Sheet.224Sheet.225Sheet.226Line.226Line Bi-directional Dotted.278Wireless Connectivity (Wi-Fi or Bluetooth LE) or Wired Connectivity (RS-485, CAN, Ethernet)Wireless Connectivity (Wi-Fi or Bluetooth LE) or Wired Connec...Wireless Connectivity (Wi-Fi or Bluetooth LE) or Wired Connectivity (RS-485, CAN, Ethernet)Line Bi-directional Dotted.280Central ThermostatCentral ThermostatCentral ThermostatConnector Arrow.201Line Arrow.186Op AmpOp AmpOp AmpMicrophoneSheet.236Sheet.237Keyword detection & voice controlKeyword Detection & Voice ControlKeyword Detection & Voice Control VSYSVSYSVSYSLine Arrow.203Line Arrow.205Line Arrow.213HVAC ControlHVAC ControlHVAC ControlRelay Control: GreenPAKRelay Control: GreenPAKRelay Control: GreenPAKLatching RelaysLatching RelaysLatching RelaysLine.214PIR Motion SensorPIR Motion SensorPIR Motion Sensor VSYSVSYSVSYSLine Arrow.194 VSYSVSYSVSYSLine Arrow.196Line Arrow.197Sheet.276 Comparator & Op AmpComparator & Op AmpComparator & Op AmpOp Amp.205PeripheralOp Amp ComparatorSheet.261Sheet.262DriverSheet.264Sheet.265Sheet.266Op Amp.214PeripheralOp Amp ComparatorSheet.270Sheet.271DriverSheet.273Sheet.274Sheet.275Sheet.277Wireless ConnectivityWireless ConnectivityWireless ConnectivitySPISPISPII2CI2CI2CPHYPHYPHYUARTUARTUARTIRQIRQIRQQSPIQSPIQSPIQSPIQSPIQSPIXTALXTALXTALXTALXTALXTALGPIOGPIOGPIOGPIOGPIOGPIOADCADCADC
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Extended Thermostat with Premium Features

WS151-4: WEBConnector Arrow.201Line Arrow.242Line Arrow.241Bridge Rectifier.184Sheet.5Sheet.6Sheet.7Sheet.8Sheet.9Sheet.10Sheet.11Sheet.12Sheet.13Sheet.14Sheet.15Sheet.16Sheet.17Sheet.18Sheet.19Sheet.20LineConnector 1.160Line ArrowConnector 1.2324VAC24VAC24VACLine Arrow.42VSYSVSYSVSYSBi-directionalAntennaSheet.30Sheet.31Sheet.32Sheet.33Sheet.34Wireless ConnectivityWireless ConnectivityWireless ConnectivityLine.83Line Arrow.84VSYSVSYSVSYSLine Bi-directional DottedNFC CoilNFC CoilNFC CoilNFC CoilSheet.42Transformer.324Line.841Line.842Sheet.46Inductor.300Sheet.48Sheet.49Sheet.50Line.103Line.104NFC ReaderNFC ReaderNFC ReaderTouch KeySheet.55Sheet.56Sheet.57Sheet.58Sheet.59Sheet.60Sheet.61Sheet.62Sheet.63VSYSVSYSVSYSTemperature & Humidity SensorTemperature & Humidity SensorTemperature & Humidity SensorIAQ SensorIAQ SensorIAQ SensorBi-directional.178Connected signals arrowLine.210WS151-4WS151-4WS151-4Connector ArrowConnected signals arrow.219SPI NOR FlashSPI NOR FlashSPI NOR FlashConnector dotted double arrowLine Dotted ArrowBlock.120TFT LCD, OLED, or MIPI DisplayTFT LCD, OLED, or MIPI DisplayTFT LCD, OLED, or MIPI DisplaySheet.98Sheet.99Sheet.100Sheet.101Line Bi-directionalTouch InterfaceTouch InterfaceTouch InterfaceLCD DriverLCD DriverLCD DriverBacklightBacklightBacklightBi-directional.246Bi-directional.319RS-485RS-485RS-485Fan.321Sheet.110Sheet.111Sheet.112Sheet.113Sheet.114Sheet.115Sheet.116Sheet.117Sheet.118Sheet.119Line Bi-directional.332Antenna.333Sheet.122Sheet.123Sheet.124Sheet.125Sheet.126Line.339RS-485RS-485RS-485Fan.280Sheet.130Sheet.131Sheet.132Sheet.133Sheet.134Sheet.135Sheet.136Sheet.137Sheet.138Sheet.139Line Bi-directional.291Antenna.292Sheet.142Sheet.143Sheet.144Sheet.145Sheet.146Line.298Motor.299Sheet.149MMMLine Bi-directional.302FanFanFanCompressorCompressorCompressorFanFanFanHVAC/Heat Pump for Room/Indoor UnitHVAC/Heat Pump for Room/Indoor UnitHVAC/Heat Pump for Room/Indoor UnitHVAC/Heat Pump for Outdoor UnitHVAC/Heat Pump for Outdoor UnitHVAC/Heat Pump for Outdoor UnitLine Dotted Arrow.384Line Dotted Arrow.385Line Dotted Arrow.386Dotted LineConnector 1.388USB-CUSB-CUSB-CUSB-CSheet.164Sheet.165Sheet.166Sheet.167Sheet.168Sheet.169Sheet.170Sheet.171Sheet.172Sheet.173Sheet.174Sheet.175Sheet.176RS-485RS-485RS-485Connector dotted double arrow.411CAN PHYCAN PHYCAN PHYEthernet PHYEthernet PHYEthernet PHYConnector dotted double arrow.417Connector dotted double arrow.418Line Bi-directional Dotted.419Line Arrow.420VSYSVSYSVSYSBuck RegulatorBuck RegulatorBuck RegulatorHVAC Controller with GUI & e-AIHVAC Controller with GUI & e-AIHVAC Controller with GUI & e-AIHVAC Controller with GUI & e-AIHVAC Controller with GUI & e-AIHVAC Controller with GUI & e-AIMotor ControlMotor ControlMotor ControlBi-directional.278Sheet.196Capacitive Touch MCUCapacitive Touch MCUCapacitive Touch MCUCTSUCTSUCTSUUARTUARTUARTSheet.217Motor Control
EU188Motor Control EU188Motor ControlEU188Motor ControlMotor ControlMotor ControlLine Arrow.186Op AmpOp AmpOp AmpMicrophoneSheet.224Sheet.225Keyword detection & voice controlKeyword Detection & Voice ControlKeyword Detection & Voice ControlVSYSVSYSVSYSLine Arrow.203Line Arrow.205Line Arrow.213HVAC ControlHVAC ControlHVAC ControlRelay Control: HVPAKRelay Control: HVPAKRelay Control: HVPAKLatching RelaysLatching RelaysLatching RelaysLine.214PIR Motion SensorPIR Motion SensorPIR Motion Sensor VSYSVSYSVSYSLine Arrow.194 VSYSVSYSVSYSLine Arrow.196Line Arrow.197Sheet.264 Comparator & Op AmpComparator & Op AmpComparator & Op AmpOp Amp.205PeripheralOp Amp ComparatorSheet.249Sheet.250DriverSheet.252Sheet.253Sheet.254Op Amp.214PeripheralOp Amp ComparatorSheet.258Sheet.259DriverSheet.261Sheet.262Sheet.263Sheet.265MCUMCUMCUSCISCISCISPISPISPII2CI2CI2CInternal Temp. SensorInternal Temp. SensorInternal Temp. SensorUARTUARTUARTI2CI2CI2CDisplay I/FDisplay I/FDisplay I/FPWMPWMPWMSCISCISCISCISCISCIEthernetEthernetEthernetUSBUSBUSBGPIOGPIOGPIOGPIOGPIOGPIOADCADCADC
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