RS232 Radio link

[Rickertsen2]

Has anybody ever tried using a 3rd party radio modem attached to the program port for uploading code and debugging?

how about rs232->802.11 converters? I have used rs232->ethernet converters on automation projects before. surely someone makes a wifi version. I suppose i could always tie an rs232->ethernet converter to a ethernet->wifi converter but thats bulky. If i went this route i would need to find software to take a TCP connection and make it look like a serial port in windows if i wanted to use IFI loader. It would be really cool to be able to access our robot wirelessly from any computer in our lab.

if rs232->802.11 is impracal then a pair of transparent radio modems would be great.

I'm hoping for a solution <$200.

BTW this is not for competition use, so don't bother telling me its not legal.

[Al Skierkiewicz]

Jim,
It is my understanding that the radio uses a modified RS422 protocol, not RS232.

[Joe Johnson]

As to uploading code, life might be tricky. There are timing issues etc that I am not sure that most radio protocols would be able to meet.

As to just getting data back and forth from a printf statement, you can probably get away with many types of radios.


I like the Bluetooth radios by AirCables.net, but others have other favorites.

I seem to recall that Kevin Watson or Mike Betts recommending these radios once But, the remote radio is only TTL & only has Tx & Rx not all the RTS, CTS, etc. pins that a "real" RS-232 port has so I think replacing the programming cable is out of the question.

Good luck.

Joe J.

[Rickertsen2]

Originally Posted by Joe Johnson

As to uploading code, life might be tricky. There are timing issues etc that I am not sure that most radio protocols would be able to meet.

Yea, you are probably right. If USB converters cause issues, then radio odems would probably really cause issues. Uploading code would be nice, but i am mainly after remote debug via some custom programs we wrote. I know that the actualy UART on the pic doesn't understand any of the flow control pins and they arn't important under debug operation. I am wondering if these are being used to signal that the computer wants to upload code.

[BrianBSL]

I haven't tried it, but you could try http://www.sparkfun.com/commerce/pro...roducts_id=582 , which includes the CTS/RTS lines. I don't think its as simple as plug-and-play, there's some config you have to do to tell the module what serial mode you will be using, and you would have to make an adapter cable to go from the header to a db-9 connector.

[Dave Flowerday]

The programming port does not require CTS/RTS lines. We built ourselves a long cable last year which contained ony TX, RX, and ground which worked fine.

Additionally, I purchased one of the BlueSMIRF modems from SparkFun last summer - they do not work to download code. As mentioned here already, I suspect this has to do with timing which is the same problem as seen with some USB converters. In an effort to correct this I wrote my own version of the IFI loader which I was in the process of tuning to address the timing dependencies, but that project got put on the back-burner as our team activities started up in the fall...

However, the BlueSMIRF does work nicely for debug output from the RC. You do have to reconfigure some of it's settings to allow it to keep up with the 115200 stream coming out of the programming port though.

[Alan Anderson]

While the enhanced BlueSMiRF lets you work without a serial cable, you will still have to physically press the "program" button on the RC, so you can't really program the robot from a distance. Even with the need to press the button, I think getting rid of the cable is likely to make things a lot more convenient.

If there were a wireless module which combined a full-featured high speed serial link and an additional pair of switches, though...that is something I might even pay for out of my own pocket.

[Dave Flowerday]

Originally Posted by Alan Anderson

If there were a wireless module which combined a full-featured high speed serial link and an additional pair of switches, though...that is something I might even pay for out of my own pocket.

One of the features I was going to attempt with my version of the IFI loader and the BlueSMIRF was to repurpose one of the CTS/RTS lines on the SMIRF to be used to "press" the program button (via the header that IFI provides). With custom loader software those lines can be easily manipulated independently.

[Kevin Watson]

Originally Posted by Rickertsen2

Has anybody ever tried using a 3rd party radio modem attached to the program port for uploading code and debugging?

how about rs232->802.11 converters? I have used rs232->ethernet converters on automation projects before. surely someone makes a wifi version. I suppose i could always tie an rs232->ethernet converter to a ethernet->wifi converter but thats bulky. If i went this route i would need to find software to take a TCP connection and make it look like a serial port in windows if i wanted to use IFI loader. It would be really cool to be able to access our robot wirelessly from any computer in our lab.

if rs232->802.11 is impracal then a pair of transparent radio modems would be great.

I'm hoping for a solution <$200.

BTW this is not for competition use, so don't bother telling me its not legal.

As others have pointed out, the various SMiRFs won't allow you to program the 'bot remotely. They will, however, make debugging of a moving 'bot much easier. I've used a pair of SMiRFs to remotely tweak the camera software via the menus and it works well.

-Kevin