Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Interfacing DHT11 sensor to microcontroller.

Status
Not open for further replies.
D

dsk2858

Member level 2
Joined
Aug 17, 2011
Messages
47
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Location
Chennai,India
Activity points
1,683
Hi,:?:
i actually bought a temperature cum humidity sensor(DHT11) which produces digital out put whose working voltage is from 3.5v to 5.5v.
But the MCU which i am using can produce only upto 3.3v from the output port pins.As this voltage can not power up the DHT11 .
could any one please provide me the solution for this.

thanking you in advance.
 

You run it from 5V and get the 3,3V for the MCU from an LDO regulator.
 
dsk2858 said:
i actually bought a temperature cum humidity sensor(DHT11) which produces digital out put whose working voltage is from 3.5v to 5.5v.
But the MCU which i am using can produce only upto 3.3v from the output port pins.As this voltage can not power up the DHT11 .
could any one please provide me the solution for this.
Click to expand...

What is the microcontroller you are using in your design? Be specific.

Does it have any 5V tolerant pins/inputs?

BigDog
 

i am using RF200PD1 MCU by SYNAPSE,which is a Zigbee based MCU. it does not have any 5V tolerant pins/inputs.
I also attached the electrical characteristics of RF200PD1 MCU and DHT11 sensor.
please suggest me which LDO regulator suites my application.
RF200PD1.jpg
DHT11.jpg
 
Last edited:

According to your attachment as well as two datasheets I have on the DHT11, the device has a normal operating voltage range of 3v - 5.5v DC, therefore you should be able to power the DHT11 at the same voltage as the RF200PD1 and no level translation/shifting would be necessary.

BigDog
 
thanku
when i am connecting the sensor to the RF200PD1 mcu should i add a resister or a capacitor.
 

dsk2858 said:
when i am connecting the sensor to the RF200PD1 mcu should i add a resister or a capacitor.
Click to expand...

No, not inline.

However, you will need a pullup resistor on the data line from the DHT11 to the RF200PD1.

The datasheet sheets I have recommend a pullup resistor value of 5KΩ for runs less than 20 meters.

BigDog
 
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top