View Full Version : 433MHz Transmitter/Reciever help.

03-11-2010, 08:37 AM
This has just kind of been dropped on me. I've read the documentation and such but have hit a brick wall trying to program these. I'm using a BS2 with the 433MHx TX(27980) and RX(27981). I need to be able to get the transmitter to send data from multiple sensors such as a GPS unit and a Digital thermometer to the receiver. Is this possible? If so, could someone please point me in the right direction to figure this out?

Mike Green
03-11-2010, 11:22 AM
It is certainly possible. There's sample code for reading from GPS receivers and digital thermometers and there's sample code for sending data over a transmitter / receiver link. Most of the sample code is found via links on the Parallax webstore pages for the various products. There are some other examples in the Nuts and Volts Columns. You'll find the index for these by clicking on the Resources tab on the main Parallax webpage.

03-11-2010, 12:22 PM
Thanks for your reply. I did as you said and really couldn't find anything pertaining to my specific need. I have the TX and RX running the programs provided with the product PDF and everything is fine. However, I need a way to transmit the data from a GPS unit and a thermometer to another BS with the Receiver. I couldn't find anything that really helped with this goal. I found a couple of articles talking about this but they were of no help because they didn't really say how this was achieved, or provide any source codes. =[ I'm really pushed for time so a nudge in the right direction would be greatly appreciated.

Mike Green
03-11-2010, 10:51 PM
The sample programs show how to send arbitrary data from one Stamp to another. The GPS sample code and thermometer sample code show how to input (and display) the data from these devices. It's your job to take the pieces of data and, rather than treat them as individual pieces, treat them as a hunk of arbitrary data to be transmitted from one Stamp to another, then do something with them on the other end.

The "433RadioCRC-V1.2" example written originally for this transmitter/receiver pair and revised for the transceiver explains in the comments at the beginning how up to 16 bytes of data can be combined to make a packet for transmission with a CRC (for error checking).

It is the nature of this forum and of embedded systems that each project is different from others. Examples may be either generic or for combinations of devices different from what you have or need. You will have to adapt the existing examples for your specific needs. From the standpoint of receive/transmit code, there's no difference between a GPS receiver and a real-time-clock chip or a thermometer and a color sensor. It's all bytes of data.

You may need to browse through the BASIC Stamp Syntax and Reference Manual and look at the examples provided for the various I/O statements used in some of these sample programs. Depending on your level of programming experience, you may need to start with some of the more basic tutorials available for downloading from Parallax.

03-25-2010, 03:20 AM
I've tried and tried to figure this out but can't unfortunately and there is no one else to do it. I was attempting to figure out how to have the TX and a GPS unit on one stamp with another recieving. I can't for the life of me figure out how to get the radio to transmit the info the GPS outputs to the RX. I have the radios sending some arbitrary data, and the GPS unit working, but I have no clue how to integrate the two and be able to see the output of the GPS on the debug window on the laptop with the RX. I really need to get this working soon but I cannot find ANY information even hinting at how to do this.

03-25-2010, 03:59 AM
You need to draw up a diagram of how you have it all connected and attach your code to your next post. If what has been offered did not help we need more from you.

- Stephen