Component: Temp / Humidity (DHT11) (Environmental): Difference between revisions

Latest revision as of 14:37, 13 July 2026

Author	Matrix TSL
Version	1.1
Category	Environmental

Temp / Humidity (DHT11) component

The DHT11 temperature and humidity sensor is a popular sensor allowing the ambient temperature and relative humidity to be monitored digitally. Humidity Range = 20% - 90% +/- 5% Temperature Range = 0 - 50 Degrees C +/- 2 Degrees C

Component Source Code

Please click here to download the component source project: FC_Comp_Source_DHT11.fcfx

Please click here to view the component source code (Beta): FC_Comp_Source_DHT11.fcfx

Detailed description

No detailed description exists yet for this component

Examples

Example Program showing how to sample the DHT11 sensor and show the temperature and humidity on an LCD. DHT11 Example

Macro reference

GetHumidityFloat

	GetHumidityFloat
Gets the humidity returned by calling SampleSensor as a floating point number.
- FLOAT	Return

GetHumidityReal

	GetHumidityReal
Gets the real number portion of the humidity returned by calling SampleSensor. If humidity is 15.8 % then this function would return 8.
- INT	Return

GetHumidityString

	GetHumidityString
Gets the humidity returned by calling SampleSensor as a string.
- STRING	Return

GetHumidityWhole

	GetHumidityWhole
Gets the whole number portion of the humidity returned by calling SampleSensor. If humidity is 15.8 % then this function would return 15.
- INT	Return

GetTempFloat

	GetTempFloat
Gets the temperature returned by calling SampleSensor as a floating point number.
- FLOAT	Return

GetTempReal

	GetTempReal
Gets the real number portion of the temperature returned by calling SampleSensor. If temperature is 15.8 degrees C then this function would return 8.
- INT	Return

GetTempString

	GetTempString
Gets the temperature returned by calling SampleSensor as a string.
- STRING	Return

GetTempWhole

	GetTempWhole
Gets the whole number portion of the temperature returned by calling SampleSensor. If temperature is 15.8 degrees C then this function would return 15.
- INT	Return

SampleSensor

	SampleSensor
Communicates with the DHT11 sensor and receives the temperature and humidity readings. Returns 0 for success, 1 for no communication detected and 2 for checksum error.
- BYTE	Return

Property reference

	Properties
	Data Pin
Microcontroller I/O Pin connected to the DHT11 sensor data pin.
	Use Checksum
The checksum value is used to ensure the data being received is correct. Yes = Only receive data if checksum is correct No = Ignore checksum
	Advanced Settings
	Clock Adjustment
On 8-bit PIC devices the timings can be a little tight as slower clock speeds and so we implement an adjustment factor to allow the sensor to function. Auto mode will attempt to automatically calculate a correct adjustment factor. Manual mode will allow you to set your own adjustment factor.

@@ Line 79: / Line 79: @@
-==Macro reference==
-===GetTempWhole===
-{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
-|-
-| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''GetTempWhole'''
-|-
-| colspan="2" | Gets the whole number portion of the temperature returned by calling SampleSensor. If temperature is 15.8 degrees C then this function would return 15.&nbsp;
-|-
-|-
-| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-s16-icon.png]] - INT
-| width="90%" style="border-top: 2px solid #000;" | ''Return''
-|}
+==Macro reference==
 ===GetHumidityFloat===
-{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
+{| class="mtx-class-macrotable wikitable"
 |-
-| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
+| width="10%" align="center" class="mtx-class-macrohead" | [[File:Fc9-comp-macro.png]]
-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''GetHumidityFloat'''
+| width="90%" class="mtx-class-macrohead" | '''GetHumidityFloat'''
 |-
 | colspan="2" | Gets the humidity returned by calling SampleSensor as a floating point number. &nbsp;
@@ Line 109: / Line 101: @@
-===GetTempString===
+===GetHumidityReal===
-{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
+{| class="mtx-class-macrotable wikitable"
 |-
-| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
+| width="10%" align="center" class="mtx-class-macrohead" | [[File:Fc9-comp-macro.png]]
-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''GetTempString'''
+| width="90%" class="mtx-class-macrohead" | '''GetHumidityReal'''
 |-
-| colspan="2" | Gets the temperature returned by calling SampleSensor as a string. &nbsp;
+| colspan="2" | Gets the real number portion of the humidity returned by calling SampleSensor. If humidity is 15.8 % then this function would return 8.&nbsp;
 |-
 |-
-| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-string-icon.png]] - STRING
+| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-s16-icon.png]] - INT
 | width="90%" style="border-top: 2px solid #000;" | ''Return''
 |}
@@ Line 124: / Line 116: @@
 ===GetHumidityString===
-{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
+{| class="mtx-class-macrotable wikitable"
 |-
-| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
+| width="10%" align="center" class="mtx-class-macrohead" | [[File:Fc9-comp-macro.png]]
-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''GetHumidityString'''
+| width="90%" class="mtx-class-macrohead" | '''GetHumidityString'''
 |-
 | colspan="2" | Gets the humidity returned by calling SampleSensor as a string. &nbsp;
@@ Line 138: / Line 130: @@
 ===GetHumidityWhole===
-{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
+{| class="mtx-class-macrotable wikitable"
 |-
-| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
+| width="10%" align="center" class="mtx-class-macrohead" | [[File:Fc9-comp-macro.png]]
-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''GetHumidityWhole'''
+| width="90%" class="mtx-class-macrohead" | '''GetHumidityWhole'''
 |-
 | colspan="2" | Gets the whole number portion of the humidity returned by calling SampleSensor. If humidity is 15.8 % then this function would return 15.&nbsp;
@@ Line 147: / Line 139: @@
 |-
 | width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-s16-icon.png]] - INT
+| width="90%" style="border-top: 2px solid #000;" | ''Return''
+|}
+===GetTempFloat===
+{| class="mtx-class-macrotable wikitable"
+|-
+| width="10%" align="center" class="mtx-class-macrohead" | [[File:Fc9-comp-macro.png]]
+| width="90%" class="mtx-class-macrohead" | '''GetTempFloat'''
+|-
+| colspan="2" | Gets the temperature returned by calling SampleSensor as a floating point number. &nbsp;
+|-
+|-
+| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-f32-icon.png]] - FLOAT
 | width="90%" style="border-top: 2px solid #000;" | ''Return''
 |}
@@ Line 152: / Line 158: @@
 ===GetTempReal===
-{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
+{| class="mtx-class-macrotable wikitable"
 |-
-| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
+| width="10%" align="center" class="mtx-class-macrohead" | [[File:Fc9-comp-macro.png]]
-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''GetTempReal'''
+| width="90%" class="mtx-class-macrohead" | '''GetTempReal'''
 |-
 | colspan="2" | Gets the real number portion of the temperature returned by calling SampleSensor. If temperature is 15.8 degrees C then this function would return 8.&nbsp;
@@ Line 165: / Line 171: @@
-===GetHumidityReal===
+===GetTempString===
-{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
+{| class="mtx-class-macrotable wikitable"
 |-
-| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
+| width="10%" align="center" class="mtx-class-macrohead" | [[File:Fc9-comp-macro.png]]
-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''GetHumidityReal'''
+| width="90%" class="mtx-class-macrohead" | '''GetTempString'''
 |-
-| colspan="2" | Gets the real number portion of the humidity returned by calling SampleSensor. If humidity is 15.8 % then this function would return 8.&nbsp;
+| colspan="2" | Gets the temperature returned by calling SampleSensor as a string. &nbsp;
 |-
 |-
-| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-s16-icon.png]] - INT
+| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-string-icon.png]] - STRING
 | width="90%" style="border-top: 2px solid #000;" | ''Return''
 |}
-===SampleSensor===
+===GetTempWhole===
-{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
+{| class="mtx-class-macrotable wikitable"
 |-
-| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
+| width="10%" align="center" class="mtx-class-macrohead" | [[File:Fc9-comp-macro.png]]
-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''SampleSensor'''
+| width="90%" class="mtx-class-macrohead" | '''GetTempWhole'''
 |-
-| colspan="2" | Communicates with the DHT11 sensor and receives the temperature and humidity readings. Returns 0 for success, 1 for no communication detected and 2 for checksum error.&nbsp;
+| colspan="2" | Gets the whole number portion of the temperature returned by calling SampleSensor. If temperature is 15.8 degrees C then this function would return 15.&nbsp;
 |-
 |-
-| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-u8-icon.png]] - BYTE
+| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-s16-icon.png]] - INT
 | width="90%" style="border-top: 2px solid #000;" | ''Return''
 |}
-===GetTempFloat===
+===SampleSensor===
-{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
+{| class="mtx-class-macrotable wikitable"
 |-
-| width="10%" align="center" style="background-color:#D8C9D8;" align="center" | [[File:Fc9-comp-macro.png]]
+| width="10%" align="center" class="mtx-class-macrohead" | [[File:Fc9-comp-macro.png]]
-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''GetTempFloat'''
+| width="90%" class="mtx-class-macrohead" | '''SampleSensor'''
 |-
-| colspan="2" | Gets the temperature returned by calling SampleSensor as a floating point number. &nbsp;
+| colspan="2" | Communicates with the DHT11 sensor and receives the temperature and humidity readings. Returns 0 for success, 1 for no communication detected and 2 for checksum error.&nbsp;
 |-
 |-
-| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-f32-icon.png]] - FLOAT
+| width="10%" align="center" style="border-top: 2px solid #000;" | [[File:Fc9-u8-icon.png]] - BYTE
 | width="90%" style="border-top: 2px solid #000;" | ''Return''
 |}
 ==Property reference==
-{| class="wikitable" style="width:60%; background-color:#FFFFFF;"
+{| class="mtx-class-macrotable wikitable"
 |-
-| width="10%" align="center" style="background-color:#D8C9D8;" | [[File:Fc9-prop-icon.png]]
+| width="10%" align="center" class="mtx-class-macrohead" | [[File:Fc9-prop-icon.png]]
-| width="90%" style="background-color:#D8C9D8; color:#4B008D;" | '''Properties'''
+| width="90%" class="mtx-class-macrohead" | '''Properties'''
 |-
 |-
@@ Line 227: / Line 231: @@
 | colspan="2" | The checksum value is used to ensure the data being received is correct. Yes = Only receive data if checksum is correct No = Ignore checksum&nbsp;
 |-
-| width="10%" align="center" style="background-color:#EAE1EA;" | [[File:Fc9-conn-icon.png]]
+| width="10%" align="center" class="mtx-class-propfolder" | [[File:Fc9-conn-icon.png]]
-| width="90%" style="background-color:#EAE1EA; color:#4B008D;" | Advanced Settings
+| width="90%" class="mtx-class-propfolder" | Advanced Settings
 |-
 |-

SteveT (talk | contribs)