# USB Relay Driver For Linux

![alt text](usbrelay.jpg "USB Relay")

A cheap USB relay available from Ebay with 1,2,4 or 8 relay output.
The double throw relay ratings are 10A 250VAC each.

The USB device is HID compatible and comes with Windows control software.
This code can control the relay vi HIDAPI which is a cross platform library. 
This code was tested under linux both on x86 and Raspberry Pi ARM.
The program is command line only as it is likely to be used by shell scripts.

The output of lsusb for the device is:
```
Bus 001 Device 003: ID 16c0:05df Van Ooijen Technische Informatica HID device except mice, keyboards, and joysticks

# lsusb -v -d 16c0:05df 

Bus 001 Device 003: ID 16c0:05df Van Ooijen Technische Informatica HID device except mice, keyboards, and joysticks
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.10
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0         8
  idVendor           0x16c0 Van Ooijen Technische Informatica
  idProduct          0x05df HID device except mice, keyboards, and joysticks
  bcdDevice            1.00
  iManufacturer           1 www.dcttech.com
  iProduct                2 USBRelay2
  iSerial                 0 
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           34
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0x80
      (Bus Powered)
    MaxPower               20mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         3 Human Interface Device
      bInterfaceSubClass      0 No Subclass
      bInterfaceProtocol      0 None
      iInterface              0 
        HID Device Descriptor:
          bLength                 9
          bDescriptorType        33
          bcdHID               1.01
          bCountryCode            0 Not supported
          bNumDescriptors         1
          bDescriptorType        34 Report
          wDescriptorLength      22
         Report Descriptors: 
           ** UNAVAILABLE **
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0008  1x 8 bytes
        bInterval              20
Device Status:     0x0000
  (Bus Powered)
```
___

## HIDAPI

http://www.signal11.us/oss/hidapi

HIDAPI is a fairly recent addition to linux and is available as a package for Fedora 20 but not for Pidora (F18). 
The package was built for Pidora (Fedora 18) using the F20 hidapi source package.

### Installing Debian Packages:
This code is a maintained package in Debian (and Raspian). Use normal apt-get commands:

```
$ sudo apt-get install usbrelay
```

Other Linux platforms will need to build the source, see below

### Protocol:
The relay modules does not set the USB serial number but has a unique serial when the HID device is queried, the current state of the relays is also sent with the serial.
The HID serial is matched and the ON/OFF command is sent to the chosen relay.

### Building The Code:
The usual make, make install dance assuming the hidapi and hidapi-devel packages have been installed. Note that there are two options for the hidapi library: hidapi-hidraw or hidapi-libusb. Different distributions have better results with one or the other. YMMV. 

```
$ sudo apt-get install libhidapi-dev libhidapi-hidraw0 git 
$ git clone https://git.com/darrylb123/usbrelay
$ cd usbrelay
$ make
$ sudo make install
### Test with a usbrelay plugged in
$ sudo usbrelay

### Build the python interface using the instructions below

To choose the alternative hidapi libraries, add the option to the make command line

### hidapi-hidraw - This is the default if no option is given
$ make HIDAPI=hidraw
### hidapi-libusb
$ make HIDAPI=libusb
```

### Docker Build:
You can also build using Docker. Assuming you have Docker installed (only tested with version 18), execute the build script:

```
$ ./build.sh
```

The usbrelay binary, libusbrelay.so and libusbrelay_py.so libraries will be built in the root directory of the repo.

### Usage:
The code needs to access the device. This can be achieved either by running the program with root privileges (so sudo is your friend) or by putting
```
SUBSYSTEM=="usb", ATTR{idVendor}=="16c0",ATTR{idProduct}=="05df", MODE="0666"
KERNEL=="hidraw*", ATTRS{busnum}=="1", ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="05df", MODE="0666"
```
to `/etc/udev/rules.d/50-dct-tech-usb-relay-2.rules`.

Running the program will display each module that matches device 16c0:05df or 0519:2018. The program can be invoked with the debug (-d) or quiet (-q) flags. The debug information is sent to stderr while the state is sent to stdout for use in scripts. The only limit to the number of these relays that can be plugged in and operated at once is the number of USB ports. Using neither the -d or -q flags just prints the state of the relays to stdout.
```
$ sudo ./usbrelay
PSUIS_1=1
PSUIS_2=0
$ sudo ./usbrelay -d
Device Found
  type: 16c0 05df
  path: /dev/hidraw1
  serial_number: PSUIS
  Manufacturer: www.dcttech.com
  Product:      USBRelay2
  Release:      100
  Interface:    0
PSUIS_1=1
PSUIS_2=0
$ sudo ./usbrelay -q
$
```
To get the relay state
```
$ sudo ./usbrelay
PSUIS_1=1
PSUIS_2=0
```
To use the state in a script:
```
$ eval $(sudo ./usbrelay)
$ echo $PSUIS_2
0
```
To set the relay state of 1 or more modules at once:
```
$ sudo ./usbrelay PSUIS_2=0
$ sudo ./usbrelay PSUIS_2=1 PSUIS_1=0
$ sudo ./usbrelay PSUIS_2=0 PSUIS_1=1 0U70M_1=0 0U70M_2=1
```
The path to a device can be used in lieu of the serial, this can be useful for devices with corrupted serials

```
$ sudo ./usbrelay /dev/hidraw1=0
```
Change the serial permanently

Use the fictitious relay 0 to set the serial permanently. If you have duplicate serials, make sure only one is plugged in when you change it.
Maximum of 5 character serial. It is probably sensible to change one module at a time to avoid serial collisions.
You may also use the device path to set the serial as above

```
$ sudo ./usbrelay
ZXCV_1=0
ZXCV_2=0

$ sudo ./usbrelay ZXCV_0=ZAQ12 # or /dev/hidraw4_0=ZAQ12
ZXCV_1=0
ZXCV_2=0
Setting new serial

$ sudo ./usbrelay
ZAQ12_1=0
ZAQ12_2=0
```

### Python Extension: 
This also optionally includes a python extension. In order to build the python extension, you must have the Python 3 development libraries installed. The docker build process will produce the python library as well.

Debian:
```
##Install Python3 dev package
# sudo apt install libpython3.5-dev
```

Fedora:
```
##Install Python3 dev pacakage
# yum install python3-devel
```

With the dependency installed, the library can be built and installed with:
```
##Build libusbrelay_py.so
$ make python
##Install to global python
$ sudo make install_py
```

Once installed, the library can be used by any python script, assuming it is running as a user with suitable permissions per the changes to udev above.

The following is a test script included as test.py, showing how to use the library:
```
import usbrelay_py
import time

count = usbrelay_py.board_count()
print("Count: ",count)

boards = usbrelay_py.board_details()
print("Boards: ",boards)

for board in boards:
    print("Board: ",board)
    relay = 1
    while(relay < board[1]+1):
        result = usbrelay_py.board_control(board[0],relay,1)
        print("Result: ",result)
        relay += 1
        
    relay = 1
    while(relay < board[1]+1):
        result = usbrelay_py.board_control(board[0],relay,0)
        print("Result: ",result)
        relay += 1
```

Once the library is installed, you can run the test script in python as follows:
```
[[$ python3 test.py
```
It will turn on and then off every relay attached to every board on your system.

## Support for Ucreatefun USB Modules
![alt text](ucreatefun.jpg "USB Relay")


A USB relay became available that is supported by the software but with severe limitations
- Status of the relays is not available
- There is no serial so there can only be one of these modules attached to a system, unless referred to by device path. The module has a USB serial number of A0001 on every module.
- The number of relays is not available

The module has a USB device ID of 0519:2018.
There are modules with 1,2,4,and 8 relays. The module accepts a request for relay 9 which turns on/off all relays.
Operating the module works the same as for the DccTech modules except the serial used is A0001
Running usbrelay without arguments prints all posible relays (8) to stdout.
```
$ sudo usbrelay A0001_2=1 # Turns on relay 2
$ sudo usbrelay /dev/hidraw4_1=1
$ sudo usbrelay A0001_9=1 # turns on all relays
```
## Referencing devices by physical USB port
Symbolic links can be used to devices to allow physical USB ports to be referenced. The following line in a /etc/udev/rules.d file will create a symbolic link with the name of the USB port:
```
KERNEL=="hidraw*",KERNELS=="*-*", SYMLINK+="hidrawport%b"
```
The following example has a ucreatefun usb relay plugged into a USB port and 2 dcttech relays plugged into a USB hub attached to another port:
```
$ ls -l /dev/hidr*
crw-------. 1 root root 243, 0 Mar  9 15:23 /dev/hidraw0
crw-------. 1 root root 243, 1 Mar  9 15:23 /dev/hidraw1
crw-------. 1 root root 243, 2 Mar  9 15:23 /dev/hidraw2
crw-------. 1 root root 243, 3 Mar  9 15:23 /dev/hidraw3
crw-------. 1 root root 243, 4 Mar  9 17:47 /dev/hidraw4
crw-------. 1 root root 243, 5 Mar  9 17:36 /dev/hidraw5
crw-------. 1 root root 243, 6 Mar  9 17:47 /dev/hidraw6
lrwxrwxrwx. 1 root root      7 Mar  9 17:47 /dev/hidrawport3-10.1:1.0 -> hidraw4 
lrwxrwxrwx. 1 root root      7 Mar  9 17:47 /dev/hidrawport3-10.3:1.0 -> hidraw6
lrwxrwxrwx. 1 root root      7 Mar  9 15:23 /dev/hidrawport3-5:1.0 -> hidraw0
lrwxrwxrwx. 1 root root      7 Mar  9 15:23 /dev/hidrawport3-5:1.1 -> hidraw1
lrwxrwxrwx. 1 root root      7 Mar  9 15:23 /dev/hidrawport3-5:1.2 -> hidraw2
lrwxrwxrwx. 1 root root      7 Mar  9 15:23 /dev/hidrawport3-6:1.0 -> hidraw3
lrwxrwxrwx. 1 root root      7 Mar  9 17:36 /dev/hidrawport3-9:1.0 -> hidraw5

$ sudo usbrelay
OMG12_1=0
OMG12_2=0
QWERT_1=0
QWERT_2=0
A0001_1=-1
A0001_2=-1
A0001_3=-1
A0001_4=-1
A0001_5=-1
A0001_6=-1
A0001_7=-1
A0001_8=-1
A0001_9=-1

  
  
  $ sudo usbrelay -d /dev/hidrawport3-10.1:1.0_1=1 /dev/hidrawport3-10.3:1.0_2=0 /dev/hidrawport3-9:1.0_2=0
Orig: /dev/hidrawport3-10.1:1.0_1=1, Serial: /dev/hidrawport3-10.1:1.0, Relay: 1 State: ff
Orig: /dev/hidrawport3-10.3:1.0_2=0, Serial: /dev/hidrawport3-10.3:1.0, Relay: 2 State: fd
Orig: /dev/hidrawport3-9:1.0_2=0, Serial: /dev/hidrawport3-9:1.0, Relay: 2 State: fd
Found 3 devices
Device Found
  type: 16c0 05df
  path: /dev/hidraw4
  serial_number: ASDFG
  Manufacturer: www.dcttech.com
  Product:      USBRelay2
  Release:      100
  Interface:    0
  Number of Relays = 2
  Module_type = 1
Device Found
  type: 16c0 05df
  path: /dev/hidraw6
  serial_number: 48VZ7
  Manufacturer: www.dcttech.com
  Product:      USBRelay2
  Release:      100
  Interface:    0
  Number of Relays = 2
  Module_type = 1
Device Found
  type: 0519 2018
  path: /dev/hidraw5
  serial_number: A0001
  Manufacturer: Ucreatefun.com
  Product:      HIDRelay
  Release:      1
  Interface:    0
  Number of Relays = 9
  Module_type = 2
Serial: /dev/hidrawport3-10.1:1.0, Relay: 1 State: ff 
1 HID Serial: ASDFG Serial: /dev/hidrawport3-10.1:1.0, Relay: 1 State: ff

Serial: /dev/hidrawport3-10.3:1.0, Relay: 2 State: fd 
2 HID Serial: 48VZ7 Serial: /dev/hidrawport3-10.3:1.0, Relay: 2 State: fd

Serial: /dev/hidrawport3-9:1.0, Relay: 2 State: fd 
3 HID Serial: A0001 Serial: /dev/hidrawport3-9:1.0, Relay: 2 State: fd
target fd ucreate 2 f0 f0


Serial: /dev/hidrawport3-10.1:1.0, Relay: 1 State: ff --- Found
Serial: /dev/hidrawport3-10.3:1.0, Relay: 2 State: fd --- Found
Serial: /dev/hidrawport3-9:1.0, Relay: 2 State: fd --- Found


```
Any

Enjoy
