LM35 series(LM35, LM35A)

LM35 series(LM35, LM35A) is a temperatures sensor IC (-55 °C to +150 °C) made by Texas Instruments. This posting will provide the OSS-ECAL(Open Source Software for Electronic Components Abstraction Layer) for LM35 series.
MCU interface : ADC

CAUTION:Please be sure to refer to the latest version of the Datasheet prior to actual design.

LM35 series(LM35, LM35A)

General description

The LM35 series are precision integrated-circuit temperature devices with an output voltage linearly-proportional to the Centigrade temperature. The LM35 device has an advantage over linear temperature sensors calibrated in Kelvin, as the user is not required to subtract a large constant voltage from the output to obtain convenient Centigrade scaling. The LM35 device does not require any external calibration or trimming to provide typical accuracies of ±¼°C at room temperature and ±¾°C over a full −55°C to 150°C temperature range. Lower cost is assured by trimming and calibration at the wafer level. The low-output impedance, linear output, and precise inherent calibration of the LM35 device makes interfacing to readout or control circuitry especially easy. The device is used with single power supplies, or with plus and minus supplies. As the LM35 device draws only 60 μA from the supply, it has very low self-heating of less than 0.1°C in still air. The LM35 device is rated to operate over a −55°C to 150°C temperature range, while the LM35C device is rated for a −40°C to 110°C range (−10° with improved accuracy). The LM35-series devices are available packaged in hermetic TO transistor packages, while the LM35C, LM35CA, and LM35D devices are available in the plastic TO-92 transistor package. The LM35D device is available in an 8-lead surface-mount small-outline package and a plastic TO-220 package.

Feature

  • Calibrated Directly in Celsius (Centigrade)
  • Linear + 10-mV/°C Scale Factor
  • 0.5°C Ensured Accuracy (at 25°C)
  • Rated for Full −55°C to 150°C Range
  • Suitable for Remote Applications
  • Low-Cost Due to Wafer-Level Trimming
  • Operates From 4 V to 30 V
  • Less Than 60-μA Current Drain
  • Low Self-Heating, 0.08°C in Still Air
  • Non-Linearity Only ±¼°C Typical
  • Low-Impedance Output, 0.1 Ω for 1-mA Load

Application

  • Power Supplies
  • Battery Management
  • HVAC
  • Appliances

OSS-ECAL specification

API Function

etSTS oLM35( etCMD cmd, float32* rlt )

The oLM35 function is an API function that executes LM35 series(LM35, LM35A) processing according to the command in the argument.

Return valueetSTSOSS-ECAL status code
eSTS_FINCompleted successfully
eSTS_ERR_MINMinimum temperature error (rlt is minimum temperature)
eSTS_ERR_MAXMaximum temperature error (rlt is maximum temperature)
eSTS_ERR_HAL_ADCHAL ADC Error
eSTS_ERR_COMMAND_CODECommand selection error
eSTS_ERR_OTHERS_RUNError during execution of other components
eSTS_ERR_ADC_OBJECTAD conversion object selection error
Parameter INetCMD cmdOSS-ECAL command code
eCMD_STARTCommand to start AD conversion.
eCMD_READCommand that reads the AD conversion value, converts the AD conversion value to a characteristic Temperature, and stores the Temperature in rlt.

AD conversion value to temperature conversion equation
Voltage value = (AD conversion value × VDD) / ( 2AD bit )
Temperature = ((voltage value – voltage offset value) / gain) + Temperature offset value (Min, Max Limit)
eCMD_START_READCommand that starts AD conversion, waits for AD conversion to finish, reads out the AD conversion value, converts the AD conversion value to a characteristic Temperature, and stores the Temperature in rlt.

AD conversion value to temperature conversion equation
Voltage value = (AD conversion value × VDD) / ( 2AD bit )
Temperature = ((voltage value – voltage offset value) / gain) + Temperature offset value (Min, Max Limit)
Parameter OUTfloat32* rltTemperature -55.0 to +150.0 [°C]

Command Correspondence Table by HAL

ArduinoArduinoeCMD_START_READ
ARMMbedeCMD_START_READ
Debian ProjectDebian(Linux)eCMD_START_READ
InfineonModusToolbox eCMD_START_READ
NXPMCUXpresso MXRT1051B_1052BeCMD_START
eCMD_READ
eCMD_START_READ
RenesasSSPeCMD_START
eCMD_READ
eCMD_START_READ
STMSTM32Cube FW_F4 eCMD_START
eCMD_READ
eCMD_START_READ
etSTS oLM35_START(void)

The oLM35_START function is an API function to start AD conversion of the LM35 series(LM35, LM35A).

Return valueetSTSOSS-ECAL status code
eSTS_FINCompleted successfully
eSTS_ERR_HAL_ADCHAL ADC Error
eSTS_ERR_OTHERS_RUNError during execution of other components
eSTS_ERR_ADC_OBJECTAD conversion object selection error

Function Correspondence Table by HAL

ArduinoArduino
ARMMbed
Debian ProjectDebian(Linux)
InfineonModusToolbox
NXPMCUXpresso MXRT1051B_1052BX
RenesasSSPX
STMSTM32Cube FW_F4 X
etSTS oLM35_READ( float32* rlt )

The oLM35_READ function is an API function that checks for the end of AD conversion, reads the AD conversion value, converts the AD conversion value to a characteristic temperature, and stores the temperature in rlt.

AD conversion value to temperature conversion equation
Voltage value = (AD conversion value × VDD) / ( 2AD bit )
Temperature = ((voltage value – voltage offset value) / gain) + Temperature offset value (Min, Max Limit)

Return valueetSTSOSS-ECAL status code
eSTS_FINCompleted successfully
eSTS_ERR_MINMinimum temperature error (rlt is minimum temperature)
eSTS_ERR_MAXMaximum temperature error (rlt is maximum temperature)
eSTS_ERR_HAL_ADCHAL ADC Error
eSTS_ERR_TIMEOUTADC Timeout error (AUTOSAR only)
eSTS_ERR_OTHERS_RUNError during execution of other components
eSTS_ERR_ADC_OBJECTAD conversion object selection error
Parameter OUTfloat32* rltTemperature -55.0 to +150.0 [°C]

Function Correspondence Table by HAL

ArduinoArduino
ARMMbed
Debian ProjectDebian(Linux)
InfineonModusToolbox
NXPMCUXpresso MXRT1051B_1052BX
RenesasSSPX
STMSTM32Cube FW_F4 XTime-out time HAL_MAX_DELAY
etSTS oLM35_START_READ( float32* rlt )

The oLM35_START_READ function is an API function that starts an AD conversion, waits for the AD conversion to finish, reads the AD conversion value, converts the AD conversion value to a temperature characteristic, and stores the temperature in rlt.

AD conversion value to temperature conversion equation
Voltage value = (AD conversion value × VDD) / ( 2AD bit )
Temperature = ((voltage value – voltage offset value) / gain) + Temperature offset value (Min, Max Limit)

Return valueetSTSOSS-ECAL status code
eSTS_FINCompleted successfully
eSTS_ERR_MINMinimum temperature error (rlt is minimum temperature)
eSTS_ERR_MAXMaximum temperature error (rlt is maximum temperature)
eSTS_ERR_HAL_ADCHAL ADC Error
eSTS_ERR_OTHERS_RUNError during execution of other components
eSTS_ERR_ADC_OBJECTAD conversion object selection error
Parameter OUTfloat32* rltTemperature -55.0 to +150.0 [°C]

Function Correspondence Table by HAL

ArduinoArduinoX
ARMMbedX
Debian ProjectDebian(Linux)X
InfineonModusToolbox X
NXPMCUXpresso MXRT1051B_1052BX
RenesasSSPX
STMSTM32Cube FW_F4 XTime-out time HAL_MAX_DELAY

Files

Folder*FileSummary
LM35_HALNAME_VERSION/samplesample.c (.cpp)Sample Application Program
sample.hSample Application Header
LM35_HALNAME_VERSIONoLM35.c (.cpp)OSS-ECAL Program for LM35 series(LM35, LM35A)
oLM35.hOSS-ECAL Header for LM35 series(LM35, LM35A)
LM35_ARDUINO.inoSample application programs for Arduino
oss_ecal.hOSS-ECAL Common Header (Ver 01.00.00 or later)
user_setting.c (.cpp)Const and Table of User setting
user_setting.hHeader of User setting
readme.mdReadme
OSS-ECAL Terms of Use.txtOSS-ECAL Terms of Use

* For HALNAME, please refer to HAL Support.

HAL Support List

MCU/Board
manufacturer
HALMCU*Development environment*HALNAME
ArduinoArduino 1.8.6ATmega2560
ATmega328P
Mega 2560 Rev3
Arduino Pro Mini 3.3V
ARDUINO
ARMMbed 6.17.0STM32F401RESTM32 Nucleo-64 boardsMBED
InfineonModusToolbox HAL Cat1 2.4.3CYBLE-416045-02CY8CPROTO-063-BLE PSoC 6 BLE Prototyping KitModusToolbox
NXPMCUXpresso SDK
iMXRT1051B_1052B
ksdk2_0
MIMXRT1052DVL6AIMXRT1050-EVKBiMXRT1051B1052B
RenesasSSP 2.4.0R7FS7G27H3A01CFCS7G2 SKSSP
STMSTM32Cube FW_F4 V1.27.1STM32F401RESTM32 Nucleo-64 boardsSTM32F4
Debian ProjectDebian(Linux) v2022.04TI AM335xBeagleBone Black – Rev CLinux

* MCU and development environment at the time of development. Even if the same HAL is used, different MCUs and development environments may not work together.

OSS-ECAL Download

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This OSS-ECAL is a sample version and can be downloaded without user registration, but please accept the OSS-ECAL Terms of Use before downloading.

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Built-in How to

How to incorporate OSS-ECAL into user programs

How to incorporate multiple OSS-ECALs in a user program (same MCU function)

How to incorporate multiple OSS-ECALs in a user program (different MCU function)

How to incorporate multiple identical electronic components into a user program

How to reduce the impact on user programs by replacing electronic components

OSS-ECAL English
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