# Noobie Having RF Module Problems/Questions?

#### DrowningTrout

Joined Aug 6, 2007
3
Ok As I Stated In The Title, I am A complete Beginner and have no Bussiness in electronics. But that dosnt stop me

Basically Im Just wanting to monitor Temp, over RF module.

I was wondering if I could Somehow transmit the data from a Temp IC using this and recieve with this.

But I have no idea how to go about doing this. Im probably not providing enough details, but im kinda lost.

#### Papabravo

Joined Feb 24, 2006
14,872
There is far from enough information to go on. Would you be terribly disappointed if you bought them and they didn't work and you had no idea how to make them work. You get what you pay for and I'm guessing that in this case it is not much. How much do you think a support call to China will cost you. How much is the company willing to spend to support you? All questions you should ask yourself.

#### beenthere

Joined Apr 20, 2004
15,819
One possible way out is to search for outfits that make weather instruments. Several make weather stations that send data to the house with an RF link. Don't think they are cheap, but they do work.

#### DrowningTrout

Joined Aug 6, 2007
3
No, I do not have to use those Modules the linked show, Basically Im just wanting Wireless Temp Sensor For about 10-20 bucks each. Thats why Im trying to make my own, those weather station ones are a little pricey for what i need. Just was trying to see if anyone has done this kinda thing before/Has any ideas, or schematics.

Goal: Make/Get Wireless Temp sensor for $10-20 Ea #### hgmjr Joined Jan 28, 2005 9,029 Greetings DrowningTrout, Based on an admittedly brief and cursory survey of RF modules both transmitters and receivers, I would say that an off the shelf solution involving the purchase of the modules and the support hardware such as a temperature sensor and support electronics plus some support hardware on the receiver side to convert to something that could be fed to a PC for analysis would run in the neighborhood of a shade under$100 US. I am assuming that much of the design and construction effort would be performed by yourself.

From what I could determine the transmitter module alone could cost out at $10 to$20 USD based on the transmit frequency as well as the reliable range of transmission.

It may be possible to cut the price somewhat by scaling back on some aspects of the performance but I don't foresee you being able to get anything useful within the price range you had in mind.

The two sources that I looked at were Linx Technologies and Zigbee.

Good Luck,
hgmjr

#### mrmeval

Joined Jun 30, 2006
833
It can be done for that price range. But to get up to do it requires a bit more investment. There are some inexpensive development kits available. I use this http://www.arduino.cc the hardware is about 35+S&H and the software is free. It has a learning curve. Once you've got the design working with the RF module you choose (look at http://www.sparkfun.com for other modules) you can then only use the parts you need and use the cheapest parts that will work.

This is one I'm considering as it's *cheap* for what it does and it comes as a pair from a good company that ships fast. http://www.sparkfun.com/commerce/product_info.php?products_id=7813

There is no way I can see you need more than 2400bps as that speed you can do temperature, humidity, wind speed and still have bandwidth to spare unless you want some insane level of updates.

Depending on what accuracy you want depends on what you need to get.
http://www.sparkfun.com/commerce/categories.php?cPath=23_82
Most microcontrollers will happily use a thermocouple and a little math and testing will get you acceptable readings that you can then transmit.

Hrm you might be able to wire that one wire digital temp sensor straight to the transmitter then have the microcontroller connected to the receiver. The microcontroller can then decode it and display it in some fashion or feed it to a PC.

Hrm I might try this at some point. I think I could do all of it and leave out the microcontroller and run it through a parallel port.....

So many ideas so little TIME.

Oh here's some nifty info for that RF transceiver pair and two different micro controllers.
http://www.sparkfun.com/datasheets/RF/KLP_Walkthrough.pdf

#### DrowningTrout

Joined Aug 6, 2007
3
Thank You mrmeval for alot of information. I am suppriesed I got alot of very helpful awnsers for the little information I provided. I am not limited on that budget, But thank you for your imput. I think i will get a Linx Tech. Module and combine with what mrmeval said.

#### hgmjr

Joined Jan 28, 2005
9,029
Here is a link to the Linx modules already mounted on a PC board with through-hole leads. They have a transmitter and a receiver version. I might just get a set for my own wireless experiments.

hgmjr