The MCP9808 is one of the more accurate temperature sensing options, with a typical accuracy of ±0.25°C and maximum accuracy of ±0.5°C over the sensor's -40°C to +125°C range and precision of +0.0625°C. The MCP9808 comes with user-programmable registers that allow user-selectable settings such as Shutdown or Low-Power modes and the specification of temperature Alert window limits and critical output limits. When the temperature changes beyond the specified boundary limits, the MCP9808 outputs an Alert signal. The user has the option of setting the Alert output signal polarity as an active-low or active-high comparator output for thermostat operation, or as a temperature Alert interrupt output for microprocessor-based systems. These features make the MCP9808 ideal for sophisticated, multi-zone, temperature-monitoring applications.
Product Link(https://www.dfrobot.com/product-2546.html)
SKU:SEN0435
- Operating Voltage: 2.7~5.5V
- Operating Current: 200μA (typical)
- Accuracy: ±0.25°C (typical) from -40°C to +125°C ±0.5°C (maximum) from -20°C to 100°C ±1°C (maximum) from -40°C to +125°C
- User-Selectable Measurement Resolution: +0.5°C, +0.25°C, +0.125°C, +0.0625°C
- User-Programmable Temperature Alert: Temperature Threshold Alert, Critical Temperature Alert
- Communication Interface: I2C (2.54mm Breakout)
- Dimension: 18.5×23mm/0.73×0.91"
- Mounting Hole Size: 2mm
- Mounting Hole Pitch: 18mm
There are two methods for using this library:
- Open Arduino IDE, search for "DFRobot_EOxygenSensor" on the status bar in Tools ->Manager Libraries and install the library.
- Download the library file before use, paste it into \Arduino\libraries directory, then open the examples folder and run the demo in the folder.
/**
* @fn sleepMode
* @brief Sensor sleep mode, lower power consumption, cannot get sensor temperature properly
* @return bool type, indicate the returned status
* @retval true, set successfully
* @retval false, register lock is not allowed to be modified
*/
bool sleepMode(void);
/**
* @fn wakeUpMode
* @brief Sensor waking up mode, sensor data can be obtained normally at this time
* @return bool type, indicate the returned status
* @retval true, set successfully
* @retval false, register lock is not allowed to be modified
*/
bool wakeUpMode(void);
/**
* @fn wakeUpMode
* @brief Get the configured power mode
* @return bool type, indicate the returned status
* @retval true, waking up mode
* @retval false, sleep mode
*/
bool getPowerMode(void);
/**
* @fn setResolution
* @brief Set resolution of the temperature sensor, the accuracy of the acquired temp is different in different resolution
* @param resolution
* @n RESOLUTION_0_5 The decimal part of the obtained temp is a multiple of 0.5 e.g. 0.5°C, 1.0°C, 1.5°C
* @n RESOLUTION_0_25 The decimal part of the obtained temp is a multiple of 0.25 e.g. 0.25°C, 0.50°C, 0.75°C
* @n RESOLUTION_0_125 The decimal part of the obtained temp is a multiple of 0.125 e.g. 0.125°C, 0.250°C, 0.375°C
* @n RESOLUTION_0_0625 The decimal part of the obtained temp is a multiple of 0.0625 e.g. 0.0625°C, 0.1250°C, 0.1875°C
* @return Set status
* @retval true, set successfully
* @retval false, set parameter error
*/
bool setResolution(uint8_t resolution);
/**
* @fn getResolution
* @brief Get resolution of the temperature sensor, the accuracy of the acquired temp is different in different resolution
* @return resolution
* @retval RESOLUTION_0_5 The decimal part of the obtained temp is a multiple of 0.5 e.g. 0.5°C, 1.0°C, 1.5°C
* @retval RESOLUTION_0_25 The decimal part of the obtained temp is a multiple of 0.25 e.g. 0.25°C, 0.50°C, 0.75°C
* @retval RESOLUTION_0_125 The decimal part of the obtained temp is a multiple of 0.125 e.g. 0.125°C, 0.250°C, 0.375°C
* @retval RESOLUTION_0_0625 The decimal part of the obtained temp is a multiple of 0.0625 e.g. 0.0625°C, 0.1250°C, 0.1875°C
*/
uint8_t getResolution(void);
/**
* @fn getTemperature
* @brief Get the current ambient temp, note that different temp accuracy can be obtained by setting different resolution
* @return The temp value is a floating point, default to reserve two decimal places, unit is °C.
*/
float getTemperature(void);
/**
* @fn getComparatorState
* @brief Get the current comparator status and temp data, which works only in comparator mode
* @return Struct for storing the current data
* @n temperate Current temp
* @n state Character string of the comparator status, compare the current temp with the upper threshold, lower threshold, and critical value
* @n value Value of the comparator status, explained as follows
* @n TA for current temp, TCRIT for critical temp, TUPPER for maximum temp, TLOWER for minimum temp
* @n 1 for TA ≥ TCRIT, TA > TUPPER, TA < TLOWER
* @n 0 for TA < TCRIT, TA ≤ TUPPER, TA ≥ TLOWER
* @n ------------------------------------
* @n | bit7 ~ bit3 | bit2 | bit1 | bit0 |
* @n ------------------------------------
* @n | reserved | 0 | 0 | 0 |
* @n ------------------------------------
*/
sComparator_t getComparatorState(void);
/**
* @fn setLockState
* @brief Set lock mode or unlock, prevent wrong operations that may change upper limit, lower limit and critical value, and unlock only by power-off reset after locking.
* @param lock
* @n CRIT_LOCK Lock threshold value, which is not allowed to be changed
* @n WIN_LOCK Lock upper and lower thresholds, which are not allowed to be changed
* @n CRIT_WIN_LOCK Lock threshold value, upper and lower limit, which are not allowed to be changed
* @n NO_LOCK No locking of threshold value, upper and lower limit
* @return bool type return the set status
* @retval true set successfully
* @retval false set parameter error
*/
bool setLockState(uint8_t lock);
/**
* @fn getLockState
* @brief Get locking status, to determine if upper limit, lower limit, and threshold can be changed
* @return Locking status
* @retval CRIT_LOCK Lock threshold value, which is not allowed to be changed
* @retval WIN_LOCK Lock upper and lower thresholds, which are not allowed to be changed
* @retval CRIT_WIN_LOCK Lock threshold and the window at the same time, upper limit, lower limit, and threshold are all not allowed to be changed
* @retval NO_LOCK No locking, threshold value, upper and lower limit are all can be changed
*/
uint8_t getLockState(void);
/**
* @fn setAlertHysteresis
* @brief Set alert temp hysteresis range, add a range to the upper limit, lower limit and threshold, hysteresis function is only applicable to reduce temp(from hot to cold).
* @details i.e, ALE level will be restored only when the temp reaches the value obtained by subtracting hysteresis temp from the upper limit/lower limit/threshold
* @details For example: maximum temp is 30.0℃, hysteresis temp is +1.5℃, the current temp is 35℃ and ALE level has flipped,
* @details and then the ALE level can only be restored when the temp goes to 30-1.5=28.5℃
* @param mode
* @n HYSTERESIS_0_0 No hysteresis, respond when reaching the specified temp
* @n HYSTERESIS_1_5 1.5℃ lag from hot to cold
* @n HYSTERESIS_3_0 3.0℃ lag from hot to cold
* @n HYSTERESIS_6_0 6.0℃ lag from hot to cold
* @return uint8_t type
* @retval 0x00 is set successfully
* @retval 0xFE is set parameter error
* @retval 0xFF is register lock is not allowed to be modified
*/
uint8_t setAlertHysteresis(uint8_t mode);
/**
* @fn getAlertHysteresis
* @brief Get hysteresis temp
* @return hysteresis type
* @retval HYSTERESIS_0_0 Temp hysteresis range +0.0℃
* @retval HYSTERESIS_1_5 Temp hysteresis range +1.5℃
* @retval HYSTERESIS_3_0 Temp hysteresis range +3.0℃
* @retval HYSTERESIS_6_0 Temp hysteresis range +6.0℃
*/
uint8_t getAlertHysteresis(void);
/**
* @fn setPolarity
* @brief Set pin ALE polarity, high polarity: pin ALE is active on high, the default is low level, which turns to high level when alert occurs.
* @details low polarity: pin ALE is active on low, the default is high level, which turns to low when alert occurs.
* @param polarity
* @n POLARITY_HIGH pin ALE is active on high
* @n POLARITY_LOW pin ALE is active on low
* @return state
* @retval 0x00 is set successfully
* @retval 0xFE is set parameter error
* @retval 0xFF is register lock is not allowed to be modified
*/
uint8_t setPolarity(uint8_t polarity);
/**
* @fn getPolarityState
* @brief Get pin ALE polarity, high polarity: pin ALE is active on high, the default is low level, which turns to high when alert occurs.
* @details low polarity: pin ALE is active on low, the default is high level, which turns to low when alert occurs.
* @return polarity
* @retval POLARITY_HIGH pin ALE is active on high
* @retval POLARITY_LOW pin ALE is active on low
*/
uint8_t getPolarityState(void);
/**
* @fn setAlertOutputMode
* @brief Set alert output mode, clearing interrupt is not required in comparator output mode, but required in interrupt mode
* @param mode:
* @n COMPARATOR_OUTPUT_MODE clearing interrupt is not required in comparator output mode,
* @n For example: set pin ALE to be active on low, when the temp exceeds the upper limit alert temp, pin ALE level turns from high to low; when it’s below the upper but above the lower limit, pin ALE level turns back to high.
* @n INTERRPUT_OUTPUT_MODE clearing interrupt is required in interrupt mode, when an alert occurs, the interrupt keep existing if it's not cleared, triggering interrupt mode means status changes from one to another
* @n For example, set lower threshold to be 20℃, upper threshold 25℃, and threshold 30℃, no interrupt occurs when temp is below 20℃; when temp exceeds 25℃, interrupt occurs and pin ALE jump, the interrupt should be cleared at the time and pin ALE is restored; in the special case, when the current temp is above the critical temp of 30℃, the interrupt mode and clearing interrupt are both invalid, the interrupt mode will be restored only when the temp drops below 30℃.
* @n DISABLE_OUTPUT_MODE After disabling output mode, no alert occurs and pin ALE is invalid.
* @return state
* @retval 0x00 is set successfully
* @retval 0xFE is set parameter error
* @retval 0xFF is register lock is not allowed to be modified
*/
uint8_t setAlertOutputMode(uint8_t mode);
/**
* @fn getAlertOutputMode
* @brief Get alert output mode
* @return mode
* @retval COMPARATOR_OUTPUT_MODE comparator output mode
* @retval INTERRPUT_OUTPUT_MODE interrupt output mode
* @retval DISABLE_OUTPUT_MODE disable output mode
*/
uint8_t getAlertOutputMode(void);
/**
* @fn setAlertResponseMode
* @brief Set alert response mode, respond to upper & lower limits and threshold; or only respond to threshold, which is inapplicable to interrupt mode.
* @param mode
* @n UPPER_LOWER_CRIT_RESPONSE enable upper/lower limits and threshold response alike
* @n ONLY_CRIT_RESPONSE disable upper/lower limits response, only enable threshold response
* @return state
* @retval 0x00 is set successfully
* @retval 0xFE is set parameter error
* @retval 0xFF is register lock is not allowed to be modified
*/
uint8_t setAlertResponseMode(uint8_t mode);
/**
* @fn getAlertResponseMode
* @brief Get interrupt response mode
* @return mode
* @retval UPPER_LOWER_CRIT_RESPONSE respond to upper/lower limits and threshold
* @retval ONLY_CRIT_RESPONSE disable upper/lower limits response, only respond to threshold
*/
uint8_t getAlertResponseMode(void);
/**
* @fn setThreshold
* @brief Set threshold value, the upper and lower thresholds, and respond according to the configured interrupt mode
* @details Responding interrupt when the temp is above the upper limit, below the lower limit and above the threshold.
* @details The critical temp must be above the upper limit
* @details The upper limit temp must be 2℃ higher than the lower limit temp
* @param crit Temp threshold, up to two decimal places, automatically processed to multiples of 0.25, range is from -40 to +125 degrees
* @param upper Upper limit temp, up to two decimal places, automatically processed to multiples of 0.25, range is from -40 to +125 degrees
* @param lower Lower limit temp, up to two decimal places, automatically processed to multiples of 0.25, range is from -40 to +125 degrees
* @return state
* @retval 0x00 is set successfully
* @retval 0xFD Upper limit temp is below lower limit, or (upper limit temp - lower limit temp < 2)
* @retval 0xFE Upper limit temp is below threshold
* @retval 0xFF is register lock, not allowed to be modified
*/
uint8_t setThreshold(float crit, float upper, float lower);
/**
* @fn clearInterrupt
* @brief Clear interrupt, only used in interrupt mode, not work in other modes
*/
void clearInterrupt(void);| MCU | Work Well | Work Wrong | Untested | Remarks |
|---|---|---|---|---|
| Arduino Uno | √ | |||
| Arduino MEGA2560 | √ | |||
| Arduino Leonardo | √ | |||
| FireBeetle-ESP32 | √ | |||
| Micro:bit | √ |
- 2021/04/16 - V1.0.0 Version
Written by ZhixinLiu(zhixin.liu@dfrobot.com), 2021. (Welcome to our website)