How to manage multiple sensors?

Help & Support Robot Parts
1

I have multiple sensors (2 to 5) that each output a rs232 serial data record every second, and these sensors may be located a 100 feet or more from my receiver and PC where I want to log the data. I have tried running serial cables back to my pc, but the cable length makes for poor signal levels and transmit errors.

What wireless transmitter/receiver pair should I use?

How do I keep the sensors from interfering from each other?
Should I figure on sending each sensor a signal to send data
and then the the next one, etc.

Do the transmissions have to be line of sight? My sensors are generally located around the exterior of a large building, so it would be best if I could get a signal around corners. Ideally I would like some communication with other sensors inside the building also.

I am working with PIC microprocessors and all my systems operate on 0-5v.

Thanks!

2

Hi dsaum,

There are many ways to approach this.

One would be to use a Mirf V2 based solution which offers alot of flexibility and up to 125 unique channels and 6 data pipes in the 2.4GHz range. That frequency should work well but if you need more penetration or observe data echoes you may want to go to 900MHz.

You could for example use these modules on your sensors via TTL level serial:

Transceiver MiRF v2 - nRF24L01 Module RP-SMA

And this one on your PC for RS-232 communication (note you will also need another nRF24L01 Module connected to this node):

SFE Transceiver Development Node MiRF v2

Add on a RP-SMA antenna to each module and you should be good to go.

If your sensor nodes need to do RS-232 serial, then a node and module at every point will work as well.