Temperature and Humidity Sensor

[fatherdaly]

Hi. I've been trying to figure out a way to make a digital Temperature and Humidity sensor for my small lab. I've done some googling and this component seems like a strong contender: Sensirion SHT75 (or SHT71) Humidity and Temperature Sensor.

Ideally I could have it set up so I could read the current values of a small LED screen and have past values stored on a computer. However I'm not entirely sure how to make this happen. Reading the 11 page datasheet hasn't done a lot to help either. It looks as if I will need a Microcontroller to receive signals from the sensor, and then I guess that could feed results to a small screen? Any advice people can give would be much appreciated.

Cheers!

 

[ericgibbs]

hi and welcome.

You will need a micro controller to talk to this sensor.

A PIC mcu would do the job. What ports do you have on your PC, eg: RS232, parallel USB etc.?

E

 

[misterT]

Maybe, if you are not familiar with microcontrollers, you could just follow this tutorial. It looks pretty good and you do not have to buy microcontroller programmers etc. if you do not want to.

https://embedded-lab.com/blog/?p=2711
https://embedded-lab.com/blog/?p=2760

 

[fatherdaly]

I don't have any computers with RS232 ports, or parallel (they're all laptops). USB would be the easiest.

 

[misterT]

I don't have any computers with RS232 ports, or parallel (they're all laptops). USB would be the easiest.

The project I posted takes its power from USB and can communicate with the PC through USB.

 

[fatherdaly]

The project I posted takes its power from USB and can communicate with the PC through USB.

Yeah sorry I hadn't seen your post, I was answering ericgibbs. The link you posted looks like it will be very useful, thanks

 

[misterT]

Yeah sorry I hadn't seen your post, I was answering ericgibbs. The link you posted looks like it will be very useful, thanks

Yeah, I know. Just wanted to point out those thing. One drawback with that board may be the USB communication. You'll need the USB code too.. easiest to work with would be probably a virtual rs232 device. I found some HID device codes, but not virtual rs232 codes.. maybe somebody more familiar with that PIC can help you with the communication part. (If you choose that board. There are many similar boards available for you to choose from).

The popular Arduino is always a good and cheap option

 

[dr pepper]

Popular and cheap sensors for that purpose are also DHT11 and DHT22 which are temp/hygro sensors, I've interfaced the DHT11 to a couple of projects, however the datasheet for the DHT22 has errors preventing me from getting it to work.
Its a non standard serial interface that can only be accesed really by some kind of processor.
I suggest if you want to do something without having to program a chip that you use a resistive or capacitive humid sensor, philips do a couple and a linear temp sensor such as a LM35 which has a voltage output.

 

[MikeMl]

Do not overlook these.