DHT 11 Humidity & Temperature Sensor - Revision history

Admin at 08:17, 9 March 2012

2012-03-09T08:17:10Z

← Older revision		Revision as of 08:17, 9 March 2012
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	will not give the response signal to MCU. Once data is collected, DHT11 will change to the lowpower-consumption		will not give the response signal to MCU. Once data is collected, DHT11 will change to the lowpower-consumption
	mode until it receives a start signal from MCU again.		mode until it receives a start signal from MCU again.


			== How to buy ==
			Click here to buy [http://www.geeetech.com/arduino-dht11-temperature-and-relative-humidity-sensor-module-p-425.html DHT 11 Humidity & Temperature Sensor]

Admin: /* Communication Process: Serial Interface */

2012-03-09T08:15:02Z

Communication Process: Serial Interface

← Older revision		Revision as of 08:15, 9 March 2012
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	[[File:Dht11Communication.jpg\|~~500px~~]]		[[File:Dht11Communication.jpg\|900px]]

	When MCU sends a start signal, DHT11 changes from the low-power-consumption mode to the		When MCU sends a start signal, DHT11 changes from the low-power-consumption mode to the

Admin: /* Communication Process: Serial Interface */

2012-03-09T08:14:38Z

Communication Process: Serial Interface

← Older revision		Revision as of 08:14, 9 March 2012
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	data + 8bit check sum. If the data transmission is right, the check-sum should be the last 8bit of		data + 8bit check sum. If the data transmission is right, the check-sum should be the last 8bit of
	"8bit integral RH data + 8bit decimal RH data + 8bit integral T data + 8bit decimal T data".		"8bit integral RH data + 8bit decimal RH data + 8bit integral T data + 8bit decimal T data".


			[[File:Dht11Communication.jpg\|500px]]

			When MCU sends a start signal, DHT11 changes from the low-power-consumption mode to the
			running-mode, waiting for MCU completing the start signal. Once it is completed, DHT11 sends a
			response signal of 40-bit data that include the relative humidity and temperature information to
			MCU. Users can choose to collect (read) some data. Without the start signal from MCU, DHT11
			will not give the response signal to MCU. Once data is collected, DHT11 will change to the lowpower-consumption
			mode until it receives a start signal from MCU again.

Admin: /* Technical Specifications: */

2012-03-09T08:12:48Z

Technical Specifications:

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	== Technical Specifications: ==		== Technical Specifications: ==
	[[File:Hdt11 specification.jpg\|~~300px~~]]		[[File:Hdt11 specification.jpg\|500px]]


	== Typical Application ==		== Typical Application ==

Admin: Created page with "== Introduction == 300px This DFRobot DHT11 Temperature & Humidity Sensor features a temperature & humidity sensor complex with a calibrated..."

2012-03-09T08:12:07Z

Created page with "== Introduction == 300px This DFRobot DHT11 Temperature & Humidity Sensor features a temperature & humidity sensor complex with a calibrated..."

New page

== Introduction ==
[[File:DHT11 sensor module.jpg|300px]]

This DFRobot DHT11 Temperature & Humidity Sensor features a temperature & humidity sensor
complex with a calibrated digital signal output. By using the exclusive digital-signal-acquisition
technique and temperature & humidity sensing technology, it ensures high reliability and
excellent long-term stability. This sensor includes a resistive-type humidity measurement
component and an NTC temperature measurement component, and connects to a high-
performance 8-bit microcontroller, offering excellent quality, fast response, anti-interference
ability and cost-effectiveness.

== Technical Specifications: ==
[[File:Hdt11 specification.jpg|300px]]

== Typical Application ==
[[File:Dht11 application.jpg|300px]]

Note: 3Pin – Null; MCU = Micro-computer Unite or single chip Computer
When the connecting cable is shorter than 20 metres, a 5K pull-up resistor is recommended;
when the connecting cable is longer than 20 metres, choose a appropriate pull-up resistor as
needed.

== Power and Pin ==
DHT11’s power supply is 3-5.5V DC. When power is supplied to the sensor, do not send any
instruction to the sensor in within one second in order to pass the unstable status. One
capacitor valued 100nF can be added between VDD and GND for power filtering.

== Communication Process: Serial Interface ==
Single-bus data format is used for communication and synchronization between MCU and
DHT11 sensor. One communication process is about 4ms.
Data consists of decimal and integral parts. A complete data transmission is 40bit, and the
sensor sends higher data bit first.
Data format: 8bit integral RH data + 8bit decimal RH data + 8bit integral T data + 8bit decimal T
data + 8bit check sum. If the data transmission is right, the check-sum should be the last 8bit of
"8bit integral RH data + 8bit decimal RH data + 8bit integral T data + 8bit decimal T data".