RF Transmitter Receiver Recommendation?

[markedwards]

I am looking for transmitter/ receiver or tranceiver hardware recommendation.
I would like to learn how to wirelessly collect about 6 different analog sensor locations into a pic.
Range (distance) would be up to 100 to 200ft max. Update rate 6 readings/ second (all 6 sensors in 1 second).
Thanks,

Mark

[mackrackit]

I would recommend anything from here.
http://www.rentron.com/PicBasic/RemoteControl.htm
The TWS-434A and RWS-434 is what I would try from your project description.

To receive data from different transmitters into one receiver, each transmitter could have a unique value in the checksum. Then the receiver MCU will know where the data came from. Lots of possibilities here.

[markedwards]

Thanks Dave for the recomendation. The Rentron parts look perfect. I'm not sure how to deal with multiple remote transmitters trying to send data at the same time. I'm thinking transceivers might be easier, I can request data from the selected remote.

Mark

[mackrackit]

I'm not sure how to deal with multiple remote transmitters trying to send data at the same time

If the remotes are constantly sending data then you should be good with sending an ID.
What you basically do is treat the ID like a checksum. If the checksum is correct the data is saved/used. Same with an ID. If ID=r1 then data is from remote #1.

[ardhuru]

If the remotes are constantly sending data then you should be good with sending an ID.
What you basically do is treat the ID like a checksum. If the checksum is correct the data is saved/used. Same with an ID. If ID=r1 then data is from remote #1.

Dave, in that case wouldnt there be constant collisions in the incoming packets, affecting the validity of the actual data seen by the receiver?

Anand

[mackrackit]

Dave, in that case wouldnt there be constant collisions in the incoming packets, affecting the validity of the actual data seen by the receiver?

Anand

Receivers are constantly being flooded with noise from everywhere. That is why the checksum or some other way of knowing if the signal being received is good or data we are after. If the ID is part of that then we know the data is good and where it came from.

[ScaleRobotics]

Update rate 6 readings/ second (all 6 sensors in 1 second).

That sounds like all six in one second.....

One of the XBee modules like this: http://www.sparkfun.com/products/8664
fits the distance, legalities, and timing specs. It's only $19.00 at DigiKey.com, and is highly configurable.

[dhouston]

That sounds like all six in one second.....

One of the XBee modules like this: http://www.sparkfun.com/products/8664
fits the distance, legalities, and timing specs. It's only $19.00 at DigiKey.com, and is highly configurable.

If it is a 1 second burst containing all 6 sensors, I agree - this is ideal.

[markedwards]

I appreciate all your insight. I work on equipment installations and it always seems like the sensors are spread out in multiple locations. Example a cooling tower has 2 or 3 temperatures, water level pressure and flow. Down a flight of stairs to the pump room, then up the ladder to the roof...
I was hoping to install a few diagnostic transmitters to temporarily monitor operating conditions.
The Xbee looks reasonably priced.

Thanks,

Ed

[dhouston]

The Xbee looks reasonably priced.

But it seems that you need multiple transmitters to avoid running wires up and down the stairs.

Can you be a bit more explicit about sensor locations and whether you want continuous or periodic operation?

[markedwards]

But it seems that you need multiple transmitters to avoid running wires up and down the stairs. ?

Yes absolutely!

Can you be a bit more explicit about sensor locations and whether you want continuous or periodic operation?

I was thinking real time data w/ 1 reading per second per each sensor (6 readings per second) would be good

Some systems operating conditions can ramp up and shut down in a matter of seconds others rarely change. I have experienced an intermittent high pressure switch
that caused rubber hoses to ocassionally fail.

I have never had an opportunity to work with radio communication and thought this would be a good project to learn.