No output from serial port on Putty
No output from serial port on Putty
(OP)
I need to control the boot process on an embedded device, so I connected serial console port pins to Putty client, but can't get any output from serial port. I use FTDI TTL-232R-RPi (USB to TTL RS232) cable. I've measured signals on serial console pins, there is -3.15V on RX pin and 0.15V on TX pin. Serial connection settings are correct, COM3, 115200, data bits 8, stop bits 1, parity: none, flow control: none. I used this FTDI cable in the past with another modem, and it worked. What can be the problem?





RE: No output from serial port on Putty
Your FTDI chip is not genuine, and the FTDI Driver is unhappy.
Something is broken.
You're on the wrong pins (not likely, but it happens).
Any number of other possibilities.
RE: No output from serial port on Putty
RE: No output from serial port on Putty
I jumper pins TX and RX on the end of serial cable and tried type in Putty, it is echoed back correctly. So this show that FTDI cable is OK.
I think I already tried to swap TX and RX pins.
RE: No output from serial port on Putty
RE: No output from serial port on Putty
Keith Cress
kcress - http://www.flaminsystems.com
RE: No output from serial port on Putty
RE: No output from serial port on Putty
If the 2-3 loopback works when connected, and doesn't when not (to distinguish internal loop back), then it's probably working.
So turn your attention to the other end, the embedded device. Perhaps it's not configured to receive.
Debugging serial ports... ...just like the good old days.