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