fit-IoT Users Forum

I have fitpc2i (serial 120111-092). I've installed Ubuntu 12.04 server on the box.

I've had no luck trying to access the serial port which comes up as /dev/ttyS0. I've installed minicom (http://linux.die.net/man/1/minicom) to test the connection: It appers that either the mini-serial cable that was shipped with the unit is bad or the serial/UART on the board isn't working.

I've tested the source of the serial signal I'm trying to read via a USB-to-RS232 coverter from FTDI:(http://www.ftdichip.com/Support/Documen ... -PLUS4.pdf)

The signal comes in just fine (over /dev/ttyUSB3) once I set the serial port options (via setserial and stty). However, if I plug in the serial port using the supplied cable and perform the same settings with /dev/ttyS0, there is nothing.

Is there anything I can do to test the cable or fitpc?

Thanks,
Dean

Dear Dean

To test the serial cable your can use a DVM. One of almost every DVM's functions is an ohm meter. Just put the each of the probes to the each end of the signal to check the shortcut presence. Repeat the procedure with each of the serial port signals.

If you'll find your serial cable ok, then you can check your serial port with a loopback setup. To create a loopback, you should shortcut the TxD/RxD and the RTS/CTS signal pairs. This setup will cause every signal you'll transmit over your serial port to be echoed back to the same port

I was able to track down one problem only to encounter another. The loopback adapter helped a lot.

I now need to ensure the serial mini adapter cable is passing through the DCD line on which I'm sending a pulse-per-second (PPS) signal. I'm seeing data come though on TX/RX but I need to ensure the PPS signal is passing through on DCD. I can see the PPS signal on a scope going into the adapter cable; but I don't have a female mini-serial plug that I can test with.

Do you know of any standard connector that I could use to test the mini-side of the adapter cable?

I'm having the same issue...I'm trying to bring a PPS signal in via RS232 pin 1, but the software doesn't see anything. I have verified the signal exists with another machine that has a normal RS232 connector.

I'm looking at the manual and it appears DCD doesn't exist on the microserial end of the cable. Can someone verify whether this is the case?


Thanks,

Eric

The DCD signal does not populated in the FitPC2i model.