enable/disable usb ?

[olivier57]

Hi,

Would it be possible to build a command (script, java...) to enable/disable 5v alimentation for one of the USB plugs ?

Thanks,

Olivier

[olivier57]

Well, no answer ? Nobody knows ?

[myCloud]

I think many, if not most, of us had to lookup the word, "alimentation."

What is it you want to do? Turn 5V power on and off?

[olivier57]

)) So sorry, thanks, I didn't notice my mistake.... I didn't want to feed my Syno, you're right, I wanted to switch on and off power of a given usb port in order to control an external relay.

[myCloud]

Perhaps this might help.

[olivier57]

Thanks, yes, this is close to what I'm thinking about but what I want to control is the electric bolt of a gate. I found a product that could do the trick (see below) and will even work with Synology as there are ubuntu commands but I was thinking that if I can power on and of 5v, I can connect directly a relay to the usb port.

Thanks for your kind help,

Olivier

http://sigma-shop.com/product/72/web-internet-ethernet-controlled-relay-board-arduino-compatible-rs485-usb.html%20wic

[myCloud]

Your link broke, but I found this. If I understand it correctly, the USB is only needed to program the board and after that, it uses a network connection. Am I wrong?

[olivier57]

I probably did a but cut/paste, the one I was thinking is this one :

http://sigma-shop.com/product/75/usb-4-relay-board-rs232-serial-controlled-pcb.html

[myCloud]

It appears that after you get the FTDI Linux USB to serial drivers installed in DSM, there won't be any need to control the USB power. The board itself probably draws a small number of milliamps. All the control is done by writing a 3 byte sequence over the serial port -- no reading involved. It would be nice to have a visual indicator of whether the gate is latched or not though.

[olivier57]

Well, I'm not sure I understand. Do you mean that if I use kmtronic stuff, I won't be able to make it work immediately with a command like their example ?

#!/bin/bash
# sends on signal to the USB relay
echo -e "\xFF\x01\x01" > /dev/ttyUSB0

Do you mean that I would have to go thru this commands http://hallard.wikidot.com/synomodules

which looks rather complicated to me and could compromise the functioning of my synology ?

Do you mean that there is another way of doing so ?

edit : having a closer search, I'm afraid I would have to go thru ftdi drivers installation (

[myCloud]

Amazingly, the USB class does not include a serial port. You need driver software for the chip in a USB to serial converter, while you don't with a device such as a USB soundcard, where the USB-compliant OS takes care of it. It would probably be productive contacting their support folks.

[olivier57]

Thanks for your help, I'll see if I carry on this way, I found different blogs going in the same direction...
http://www.bydavy.com/2012/01/compiling-linux-kernel-modules-for-synology-devices/

Getting rather complicated my basic idea to switch usb power on and off to ... feed the relay

[myCloud]

Best wishes for a successful solution!

[olivier57]

Hi,

So it's ok, it works !

For those who want to drive external stuff with usb and relays, I recommend
- kmtronic products (I used http://www.sigma-shop.com/product/75/usb-4-relay-board-rs232-serial-controlled-pcb.html) and
- this page http://hallard.wikidot.com/synomodules that I followed to build the drivers. Thanks to Charles-Henri Hallard.

I would add a few comments to avoid some difficulties I encountered (but I'm Ubuntu newbie) :
install ncurse with "apt-get install ncurses-dev"
use "make arch/powerpc/lib/crtsavres.o" to avoid a file not found during "make modules"
use make -i as we just need the drivers and don't care if any problem elsewhere.

As a conclusion, I would appreciate if someone is able to explain me how this set of commands
mknod /dev/ttyUSB0 c 188 0
insmod /opt/lib/modules/2.6.32/usbserial.ko
insmod /opt/lib/modules/2.6.32/ftdi_sio.ko
insmod /opt/lib/modules/2.6.32/pl2303.ko

allows
echo -e "\xFF\x01\x01" > /dev/ttyUSB0 to be received by DS209II+ front port. Is it because "0" is its number ?