Serial communication help

[tdlrali]

There's a second serial port on the RC, labeled TTL. That second programming port works just like the 1st. If the sound chip needs RS232 levels, you can use the little converter board that came with the cmucams.

Ideally, I could send it the words to say via the program port and a terminal app on my laptop

What prevents you from connecting the laptop directly to the sound chip?

[Joe Johnson]

Originally Posted by tdlrali

There's a second serial port on the RC, labeled TTL. That second programming port works just like the 1st. If the sound chip needs RS232 levels, you can use the little converter board that came with the cmucams.


What prevents you from connecting the laptop directly to the sound chip?

If you don't have the CMUCAM level shifter, it is almost trivial to build one with a MAX232 or MAX233 chip -- add a few caps, a few wires and some solder and you're in business.

Alternatively, you may be able to track down the level shifter on the sound board you are using and tap into the board where the serial data is TTL voltages again -- this will take more courage on your part, but you seem like a bold kind of guy, so I think you could handle it (don't forget to cut the trace from the output of the level shifter so that the IFI output and the level shifter are not fighting to control the same line).

Good luck,

Joe J.

[dpeterson3]

I was told that there were three ports on the controler and that I could only use the program port. Last year was my first year actually in competition. All my programming knowledge and how the IFI contoller works comes from what I was told. Basically our programmer graduated this year, and all I have to go on is what little he told me. I want to interface the chip with the IFI controller so that it would appear as if the robot was talking. Also, I would not have to be teathered that way. I guess I should have made that more clear. That is why I don't think I can send commands from the laptop. If I understand correctly, my laptop can not send commands from the OI to the robot. Any programing tips are welcome also. Everything is stored at our partner school, so I can not access it easily. If we show off the robot, I will only have a day or two to troubleshoot programming. I need it to be close to working the first time. All I have to wrok with right now is the lastest version of MPlab, the MC18 compiler and IFI_Loader that I found online yesterday.

[Mark McLeod]

Here's an example program that uses one of the digital outputs to send serial commands to an LCD screen.
http://www.team358.org/files/program...x_LCD_Demo.zip
Some mods will be necessary to make it compile with the latest MCC18 compiler though. This used v2.4 although the serial part of it is generic and doesn't care.

Commanding it via a laptop through the program port is fairly easy as well.