Seeking advise/information for using XBee for RF com between independent modules
trooks
Posts: 228
Chris, (and others that may have specific experience or knowledge)
A friend and I are working on a project that involves distributed modules doing precise mechanical task that involve critical timing.
I have already built and tested several modules using 16 bit processors and have them hard wired together. I have tried using separate TX and RX modules but have not been able to get error free communications. The end product will likely be using 16F57 chips.
The XBee seems to be the answer for me. However I am in need of a bit of training and documentation to make the most efficient use of them.
Are there any books available through Parallax(or other sources) that you can recommend?
Also the last time I did anything involving bread boarding was with 8088 processors and 54XX ICs so I am a bit out of date there. I am thinking of getting a more up to date rig that can use wireless KBD/Mouse with VGA display that can double as an oscope. I understand that Parallax may have all that I need but would like to get my hands on as much hard copy documentation as I can before making the plunge.
Thanks much in advance for your help,
Tim
A friend and I are working on a project that involves distributed modules doing precise mechanical task that involve critical timing.
I have already built and tested several modules using 16 bit processors and have them hard wired together. I have tried using separate TX and RX modules but have not been able to get error free communications. The end product will likely be using 16F57 chips.
The XBee seems to be the answer for me. However I am in need of a bit of training and documentation to make the most efficient use of them.
Are there any books available through Parallax(or other sources) that you can recommend?
Also the last time I did anything involving bread boarding was with 8088 processors and 54XX ICs so I am a bit out of date there. I am thinking of getting a more up to date rig that can use wireless KBD/Mouse with VGA display that can double as an oscope. I understand that Parallax may have all that I need but would like to get my hands on as much hard copy documentation as I can before making the plunge.
Thanks much in advance for your help,
Tim
Comments
We have a book for the XBee Starter Kit that gives information on how to get started but the code examples are for BASIC Stamp and Propeller microcontrollers, not PIC. Still you could download the PDF and see if you can at least get an understanding from the information presented.
As for your current issues using separate modules...while the XBee modules will solve the problem of data getting back and forth uncorrupted, there is always the chance the data won't make it at all. When using wires in an ideal system you can be sure what you send down the wire gets to the other side since there's a physical connection. With wireless there are no guarantees. The XBee radios attempt to resend lost packets a few times but even if this succeeds, you said you application requires critical timing. In RF you can't always be assured of that because of the possibility of noise interfering with your signal which can cause delays or worse, that the data doesn't make it to the destination at all.
Chris, Thanks much for the info,
I already have a BS2 on a USB BOE and am sure my Basic Programming skills can set up a system of 'keep-alive' signaling. The unit with the least overhead of sensor monitoring will be the one that monitors all other modules to make sure all are still 'on-line'.
I dare not give away too much info regarding what we are about but there will only be one super critical signal sent to all units. The rest of the time all units will simply maintain communications and report status changes. I can tell you that each module is under the control of a _team_ member. The process can be made to work even if one unit is out of the loop but only if I write the code to cover that instance. That would mean one disappointed team member _missed_ out but the overall team effort would be a success.
I will not know for sure how/if my timing requirements can be met until I get my hands on a couple of XBees and start the final steps in my design and coding. I am awaiting clearance of a mid-month check at he bank and will be ordering another BS2 and a couple of XBees to test/verify the timing involved.
As long as I buy something once and a while I do get to continue picking your brain - right?<Very Big Grin>
Tim
Tim,
Thanks to these Support/Discussion Forums you can continue to pick thousands of brains all with no purchase required. :thumb: Of course, it helps if you're using products we can identify with.
Maybe this post will get the job done.
Tim
(Thoroughly amazed that I still have power and internet - the sound of drip-drip-drip and the occasional fall of an icicle is wonderful)
Tim
I marked this solved for you.
In the future, you can go to the first post and and in "Go Advanced", you can change that.
Jim
Jim,
Thank You.
I am making a note of that. I am confident that I will be needing to use that information a few times<Grin>.
Tim