A little ext breakout (SMD style)

[urjaman]

It provides the pandora kernel/u-boot serial port (on the pandora side it is /dev/ttyO2 on the new kernels) behind an usb to serial converter chip (ch340g). That's pretty much it.

Modern linux has drivers for the usb-serial chip (named ch341-uart), and there are some cruddy windows drivers out in the net too.
So if you plug it in on a linux PC, you should get a /dev/ttyUSBn device. Where n is a number, 0 if you dont have any other usb serial ports.

And if you plug it into the pandora, you should be able to do eg.
picocom -b 115200 -f n /dev/ttyUSB0
or
minicom -D /dev/ttyUSB0 -b 115200 -o
(or something like that, whatever serial port thingy you like)
and then boot the pandora and you should get something to the tune of this (my u-boot is something random i think, so the details would vary)

Texas Instruments X-Loader 1.5.1 (Dec 10 2013 - 01:20:37)
OpenPandora System
OMAP3530-GP ES3.1
NAND: 2c:bc MT29F4G16ABBDA3W
Loading u-boot.bin from nand


U-Boot 2016.03-15746-g5299cc3-dirty (Mar 23 2016 - 23:58:23 +0000)

OMAP3530-GP ES3.1, CPU-OPP2, L3-165MHz, Max CPU Clock 600 MHz
OMAP3 Pandora + LPDDR/NAND
I2C:   ready
DRAM:  512 MiB
NAND:  512 MiB
MMC:   OMAP SD/MMC: 0, OMAP SD/MMC: 1
*** Warning - bad CRC, using default environment

OMAP die ID: 0e00900b040398cf0000000075be0004
Net:   Net Initialization Skipped
No ethernet found.
Hit any key to stop autoboot:  0
Card did not respond to voltage select!
ubi0: attaching mtd1
ubi0: scanning is finished
ubi0: attached mtd1 (name "mtd=3", size 10 MiB)
ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 129024 bytes
ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 512
ubi0: VID header offset: 512 (aligned 512), data offset: 2048
ubi0: good PEBs: 80, bad PEBs: 0, corrupted PEBs: 0
ubi0: user volume: 1, internal volumes: 1, max. volumes count: 128
ubi0: max/mean erase counter: 47/20, WL threshold: 4096, image sequence number: 1048321096
ubi0: available PEBs: 0, total reserved PEBs: 80, PEBs reserved for bad PEB handling: 2
Loading file 'autoboot.txt' to addr 0x82000000...
Done
## Executing plain script at 82000000, size 240
Unmounting UBIFS volume boot!
ubi0: detaching mtd1
ubi0: mtd1 is detached
ubi0: attaching mtd1
ubi0: scanning is finished
ubi0: attached mtd1 (name "mtd=3", size 10 MiB)
ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 129024 bytes
ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 512
ubi0: VID header offset: 512 (aligned 512), data offset: 2048
ubi0: good PEBs: 80, bad PEBs: 0, corrupted PEBs: 0
ubi0: user volume: 1, internal volumes: 1, max. volumes count: 128
ubi0: max/mean erase counter: 47/20, WL threshold: 4096, image sequence number: 1048321096
ubi0: available PEBs: 0, total reserved PEBs: 80, PEBs reserved for bad PEB handling: 2
Loading file 'uImage' to addr 0x82000000...
ubi0: fixable bit-flip detected at PEB 47
ubi0: schedule PEB 47 for scrubbing
ubi0: scrubbed PEB 47 (LEB 0:34), data moved to PEB 26
ubi0: fixable bit-flip detected at PEB 55
ubi0: schedule PEB 55 for scrubbing
ubi0: fixable bit-flip detected at PEB 55
ubi0: scrubbed PEB 55 (LEB 0:69), data moved to PEB 22
Done
## Booting kernel from Legacy Image at 82000000 ...
   Image Name:   Linux-3.2.80
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    2843904 Bytes = 2.7 MiB
   Load Address: 80008000
   Entry Point:  80008000
   Verifying Checksum ... OK
   Loading Kernel Image ... OK

Starting kernel ...

Uncompressing Linux... done, booting the kernel.

.-------.                                          
|       |                  .-.                     
|   |   |-----.-----.-----.| |   .----..-----.-----.
|       |     | __  |  ---'| '--.|  .-'|     |     |
|   |   |  |  |     |---  ||  --'|  |  |  '  | | | |
'---'---'--'--'--.  |-----''----''--'  '-----'-'-'-'
                -'  |
                '---'

The Angstrom Distribution pandora ttyO2

Angstrom 2010.4-test-20141019 pandora ttyO2

pandora login:

and then maybe even login , hopefully, atleast thats the point.

 

[urjaman]

In case you wanted something with which to interface the pandora ext port to whatever electronics that can deal with a 2.8V-output UART, i designed something .

https://github.com/urjaman/pnd-ser-6pin

The schematic can be viewed in the pdf thats in github, and oshpark has pcb renders at
https://oshpark.com/shared_projects/iGVFJWpa

I'm not in a hurry to make any, but i think i will eventually (in some months), so it's totally untested, but anyways..
The outputs (and the VCC in the 6-pin header) are at 2.8V or whatever you program the pandora VAUX4 to,
and the inputs are 5V-tolerant TTL compatible.

(And yeah it's the UART2 which would be /dev/ttyO1 i think and with flow control to the 6-pin FTDI-cable-style 0.1" header...)