A little ext breakout (SMD style)


urjaman

"I Know. We're going for a ride."
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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)

Code:
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 :p, hopefully, atleast thats the point.
 

urjaman

"I Know. We're going for a ride."
Joined
Jan 6, 2009
Messages
1,111
Age
31
Location
Finland
Website
urjaman.dy.fi
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...)
 
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