RS 232 levels

[dfeldman]

Hi. This forum has been really quite helpful for getting the VR Stamp up and running and getting code written for the RSC-4128.

I have a quick question regarding the RS-232 serial port on the Easy VR-Stamp board. I have been trying to connect the Easy VR-Stamp to my PC via a null-modem cable to verify the bytes sent to that port but haven't gotten any signal out. Should the Easy VR-stamp be connected via a serial cable and not a null-modem cable?

Also, does the VR-Stamp output TTL level voltages?

Thanks a bunch!
Dan

[milan]

Should the Easy VR-stamp be connected via a serial cable and not a null-modem cable?

Yes.

Also, does the VR-Stamp output TTL level voltages?

Do you mean outputs: at the RS232 or at the ports IDC10 connectors

[dfeldman]

I am still having some trouble getting the rs232 working properly. Which of the MikroElektronika examples is most appropriate for testing out the RS232 output? Also, could you please provide instructions for how to set up the hyperterminal so that it properly receives the easy vr stamp rs232 outputs?

With regards to the TTL level question, I was wondering if at the P0.1 and P0.0 pins, the output was at TTL levels. It seems to be the case given the max232 chip connecting the vr stamp to the db-9 connector, but I just wanted to make sure.

Thanks,
Dan

EDIT:
It seems like once I post a question, I have an insight into the problem ...
I used the rpmsg example with a baudrate of 9600, 8 data bits, 1 stop bit, no parity and hardware flow control and I was able to get valid output. The TTL question remains however.

[milan]

The TTL question remains however.

It is not standard TTL.

For characteristics,
look at the RSC-4128_Datasheet -> DC characteristics

[eforman]

could non-standard TTL be the reason why I cannot get serial output to work to my laptop? i'm using the Easy-VR Stamp board as well.

i have tried the mikroC compiler Terminal and HyperText. oddly, I see some characters in Terminal but not in HyperText, but they are illegible nonsense any way. I am using 9600baud 8bit 1stopbit no parity and i have SW1 jumpers 5 and 6 set.

what else could i be doing wrong?