Help with serial port

[jimbolaya]

I have a POGO-P21 that I'm trying to get up and running with a disk on module SATA drive. After reading the whole post several times on getting this to boot from SATA and having no luck, I wanted to get the serial port connected to see if I could get more information. Unfortunately, I'm not getting anything from the serial port either.

Every reference has the ground at pin 4 (closest to the power supply) and 3.3v at pin 1 (furthest from the power supply, it's pin 1 because the solder pad is square). Oriented that way pin 3 is RXD and pin 2 is TXD (from every reference I've found). I got a TTL-232R-3V3 that I have hooked up to a 2mm plug as follows

Black (GND) Pin 4
Yellow (RXD) Pin 3
Orange (TXD) Pin 2
Nothing on Pin 1. If I put the 3.3v on pin 1 I have to pull the serial cable to get it to shut down.

Then I run "screen /dev/ttyUSB0 115200 8N1" (this is my only USB serial cable) but I get nothing on the screen. Sometimes when I plug the pogo in, it gives me a strange character, but most of the time there's nothing in the terminal window.

Thinking that I should have the RXD on the serial cable go to the TXD on the board and vice-versa, I've also reversed the position of those two pins. No luck there either.

Right now, if I plug the SATA drive in, the big green LED flashes for a bit then goes silent with the network flashing variously. I don't get any DHCP traffic at all. If I remove the SATA drive, it starts up fine. I don't see any serial traffic in either case.

James

[Geoff]

Just a few things to try, if you like:

1. If you have the exact same kernel in NAND and on the SATA DOM, then an exact copy of the USB rootfs to the SATA DOM rootfs should boot up just fine. (Maybe you were just having network issues.)

2. If you have a spare SATA HDD lying around, then you could dd the DOM onto the HDD and play around with that first; see if that boots up OK. If not, you could boot up from USB with the SATA HDD powered down, and then power up the HDD. Then "echo "0 0 0" > /sys/class/scsi_host/host0/scan" should find its partitions and mount those containing filesystems. I don't know if it's OK to hotplug a SATA DOM or power it up after booting. If so, then you could see whether it mounts OK.

[emax20000]

Hi , i've a pogoplug pro and I have tried to connect in serial but on the screen I only incomprehensible characters, I've tried different connection speeds from 9600 to 115200, but the result does not change, I used a standard serial port.
Can help me?

[WarheadsSE]

12v != 3.3v => Bad
115200,n,8