PL-2303 Code 10 error

알리에서 싸다고 UART2USB 이런거 사면 PL2303칩 들어간걸 받게된다
문제는 리눅스는 별이상 없이 인식하는데 윈도우에서는 CODE 10 에러를 띄운다
제조사에서는 저렴한 FAKE 칩 쓰면 그렇다고 한다

리눅스에서 인식되는 정보 “067b:2303 Prolific Technology, Inc. PL2303 Serial Port”

뭐 이미 샀으니까 버리긴 아깝고 드라이버를 Fake detect 하기 이전의 버전으로 내리면 문제는 해결된다.
http://www.totalcardiagnostics.com/support/Knowledgebase/Article/View/92/20/prolific-usb-to-serial-fix-official-solution-to-code-10-error
여기서 받은 64bit 32bit를 설치하면 된다

다음에 살때는 PL2303은 피해서 사야겠다..

Linux Loop Device

losetup 으로 루프디바이스를 설정하면 파티션들이 보여야되는데 보이지 않는 문제 발견

http://askubuntu.com/questions/69363/mount-single-partition-from-image-of-entire-disk-device#673257

loop module max_part config
This is a decent method before 16.04.
loop is a kernel module, built into the kernel in Ubuntu 14.04.
If you configure it right, Linux automatically splits up the devices for you.
If you configure it right, Linux automatically splits up the devices for you.

cat /sys/module/loop/parameters/max_part

says how many partitions loop devices can generate.
It is 0 by default on Ubuntu 14.04 which is why no auto-splitting happens.
To change it, we can either add:

options loop max_part=31

to a file in /etc/modprobe, or:

GRUB_CMDLINE_LINUX="loop.max_part=31"

to /etc/default/grub and then sudo update-grub.
How to set a module parameter is also covered at: How to add kernel module parameters?
After a reboot, when you do:

sudo losetup -f --show my.img

it mounts the image to a /dev/loopX device, and automatically mounts the partitions to /dev/loopXpY devices.

의 해결책은 조금 귀찮으므로
https://lwn.net/Articles/274113/
에서 제시한  “modprobe loop max_part=63” 를 사용,

root@debian:~/z# ls /dev/loop0p*
/dev/loop0p1 /dev/loop0p2 /dev/loop0p3 /dev/loop0p4 /dev/loop0p5 /dev/loop0p6 /dev/loop0p7

잘된다

Sanwu TDA7492P + CSR8635 Bluetooth 4.0 Mod

http://www.ebay.com/itm/262799716349
이런걸 샀는데 화이트 노이즈가 너무너무너무 심하다….
정지나 일시정지엔 괜찮은데 조용한 부분에서 화이트 노이즈가 심한데 그걸 또 앰프가 증폭…

찾아보니 이런게 있다
http://www.360customs.de/2017/01/sanwu-tda7492p-csr8635-bluetooth-4-0/

 

아직 시도는 안해봤는데  가운데있는 NE5532 amp는 왜있는지 모르겠다….

USB charging sepecs

 

  1. Standard downstream port (SDP) This is the same port defined by the USB 2.0 spec and is the typical form found in desktop and laptop computers. The maximum load current is 2.5mA when suspended, 100mA when connected and not suspended, and 500mA (max) when configured for that current. A device can recognize a SDP with hardware by detecting that the USB data lines, D+ and D-, are separately grounded through 15kΩ, but it still needs to enumerate to be USB compliant. In USB 2.0, it is not strictly legal to draw power without enumerating, although much of present-day hardware does just that, and in violation of the spec.
  2. Charging downstream port (CDP) BC1.1 defines this new, higher current USB port for PCs, laptops, and other hardware. Now the CDP can supply up to 1.5A, which is a departure from USB 2.0 because this current can be supplied before enumeration. A device plugged into a CDP can recognize it as such by means of a hardware handshake implemented by manipulating and monitoring the D+ and D- lines. (See USB Battery Charging Specification, section 3.2.3.) The hardware test takes place before turning the data lines over to the USB transceiver, thus allowing a CDP to be detected (and charging to begin) before enumeration.
  3. Dedicated charging port (DCP) BC1.1 describes power sources like wall warts and auto adapters that do not enumerate so that charging can occur with no digital communication at all. DCPs can supply up to 1.5A and are identified by a short between D+ to D-. This allows the creation of DCP “wall warts” that feature a USB mini or micro receptacle instead of a permanently attached wire with a barrel or customized connector. Such adapters allow any USB cable (with the correct plugs) to be used for charging.

 

http://www.usb.org/developers/docs/devclass_docs/USB_Battery_Charging_1.2.pdf

 

https://www.maximintegrated.com/en/app-notes/index.mvp/id/4803