912 MHz RF Transceiver Questions

kenwtn

Hi,

·· I want to be able to comunicate commands to my robot from my PC using Visual Basic and receive information from my robot. Is the 912 MHz RF Transceiver up to the task? Does the robot micro controller need to sit on the SERIN command and wait or can it do other work and check for commands couple of times a second?

Chris Savage

Hello,

The 912MHz transceiver is basically just an RF serial link in the simplest sense. What you need to focus on is how the two devices communicate. I would look at the example code for the Microsoft Robotics Studio since it is designed to do much the same thing. The EB500 is a lot like the 912MHz transceiver in that, to the BASIC Stamp, it is just a serial device. So looking at that code should help you see how the SERIN/SEROUT were handled. I hope this helps. Take care.

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Chris Savage
Parallax Tech Support

kenwtn

From looking at the code it appears the 2 units know when they are linked up. If that is the case then you should be able to do other task and whenever come online and link to the other unit. Did I understand that correct?

Chris Savage

Hello,

Yes, the EB500 knows when a connection has been made to it.

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Chris Savage
Parallax Tech Support

MSDTech

The problem you will run into is that communications are not buffered. If the PC sends a request and the BS2 isn't listening at that point in time, the request will be ignored. You need to make sure that there is a feedback to let the sender know the message has been received and is being acted upon.
The other option is to set the two units up in a "master" and "slave" relationship. In this case the slave waits for instructions, completes them, then reports the results back to the master.
Both systems have been used successfully, but you need to know the limitations of each as you are designing your communications architecture.