forum.excito.org

I try to connect to by B3 using a serial cable. I have read [1] and soldered the leads correspondingly. Since my local supplier did not carry the sr232-to-usb thing as recommenden in [1], I just got a plain serial jack and soldered the pins 2, 3, and 5 for rx, tx, and ground, respectively. I use screen on the linux command line as

screen /dev/ttyS0 115200

where the baud rate is taken from [1]. I get running lines of special characters while booting the B3 but no propper screen. Now, since the cable is home made and I am no expert in serial connections, I would apprechiate if anyone could give me a hint if my command and/or my soldering is wrong such that I know where to start digging. Moreover, what is the expected screen on boot?

Thank you in advance.


[1] This would be the site on the serial connection from the b3 wiki, but the forum does not allow me to put the url in, since it "looks too spammy".

Do NOT connect that construction to a PC serial port. Normal RS232 ports use +/- 12V (or similar, don't remember exactly), while the B3 board serial port operates at 3.3V. There is a risk that 12V on the RX input will fry the serial port forever.

You need either:
- an USB to TTL serial converter as recommended in the wiki post (http://wiki.excito.org/wiki/index.php/S ... cess_on_B3)
or
- a RS232 to TTL (3.3V) converter in order to convert the high voltages to 3.3V. There are tons of those around as well, based on the MAX232 IC or variants of it.

So try this and lets hope you didn't kill the serial port input. (It's a good sign that you still see incoming garbled characters). Good luck!

Thanks for this really fast reply. I will try and hope that there is no permanent damage already done.