Command detect

Syntax: detect <options>

Scans the system for displays supporting the Monitor Control Command Set (MCCS), most commonly using DDC/CI but alternatively using USB for communication. This command reports the results of the display search, which also is performed in the background as part of most ddcutil commands.

The output varies by verbosity.

Normal output:

$ ddcutil detect
Display 1<
   I2C bus:             /dev/i2c-7   
   EDID synopsis:  
      Mfg id:           ACR
      Model:            Acer X243W
      Serial number:    LAG040064310
      Manufacture year: 2007
      EDID version:     1.3
   VCP version:         2.1

Display 2
   I2C bus:             /dev/i2c-8
   EDID synopsis:
      Mfg id:           DEL
      Model:            DELL P2411H
      Serial number:    F8NDP11G119U
      Manufacture year: 2011
      EDID version:     1.3
   VCP version:         2.1

Display 3
   I2C bus:             /dev/i2c-10
   EDID synopsis:
      Mfg id:           HWP
      Model:            HP Z22i
      Serial number:    CNC51301ZP
      Manufacture year: 2015
      EDID version:     1.3
   VCP version:         2.2

Display 4
   I2C bus:             /dev/i2c-14
   EDID synopsis:
      Mfg id:           DEL
      Model:            DELL U3011
      Serial number:    PH5NY2CIANXL
      Manufacture year: 2012
      EDID version:     1.4
   VCP version:         2.1

Option: --brief, --terse

Presents a summary report of each detected display, in an easily machine readable form.

$ ddcutil detect --brief
Display 1
   I2C bus:             /dev/i2c-7
   Monitor:             ACR:Acer X243W:LAG040064310

Display 2
   I2C bus:             /dev/i2c-8
   Monitor:             DEL:DELL P2411H:F8NDP11G119U

Display 3
   I2C bus:             /dev/i2c-10
   Monitor:             HWP:HP Z22i:CNC51301ZP

Display 4
   I2C bus:             /dev/i2c-14
   Monitor:             DEL:DELL U3011:PH5NY2CIANXL

Option: ***--verbose ***

Show additional information, including the EDID.

$ ddcutil detect --verbose
Display 1
   I2C bus:             /dev/i2c-7
      I2C address 0x50 (EDID) responsive: true 
      Is eDP device:                      false
      I2C address 0x37 (DDC) responsive:  true 
      /sys/bus/i2c/devices/i2c-7/name:   AMDGPU i2c bit bus 0x92
   EDID synopsis:
      Mfg id:           ACR
      Model:            Acer X243W
      Serial number:    LAG040064310
      Manufacture year: 2007
      EDID version:     1.3
      Product code:     0
      Binary sn:        1952453327 (0x746012cf)
      Extra descriptor: 
      Video input definition: 0x80 - Digital Input
      Supported features:
         DPMS active-off
         Digital display type: RGB 4:4:4
         Standard sRGB color space: False
      White x,y:        0.313, 0.329
      Red   x,y:        0.640, 0.330
      Green x,y:        0.300, 0.608
      Blue  x,y:        0.150, 0.060
      Extension blocks: 0
   EDID source: 
   EDID hex dump:
              +0          +4          +8          +c            0   4   8   c   
      +0000   00 ff ff ff ff ff ff 00 04 72 00 00 cf 12 60 74   .........r....`t
      +0010   2e 11 01 03 80 34 20 78 2a ef 95 a3 54 4c 9b 26   .....4 x*...TL.&
      +0020   0f 50 54 a5 4b 00 81 80 81 00 81 0f 95 00 95 0f   .PT.K...........
      +0030   a9 40 b3 00 01 01 28 3c 80 a0 70 b0 23 40 30 20   .@....(<..p.#@0 
      +0040   36 00 06 44 21 00 00 1a 00 00 00 fd 00 38 4c 1e   6..D!........8L.
      +0050   52 11 00 0a 20 20 20 20 20 20 00 00 00 fc 00 41   R...      .....A
      +0060   63 65 72 20 58 32 34 33 57 0a 20 20 00 00 00 ff   cer X243W.  ....
      +0070   00 4c 41 47 30 34 30 30 36 34 33 31 30 0a 00 68   .LAG040064310..h
   VCP version:         2.1
   Controller mfg:      Mstar
   Firmware version:    0.3
   Monitor returns DDC Null Response for unsupported features: false

Display 2
   I2C bus:             /dev/i2c-8
      I2C address 0x50 (EDID) responsive: true 
      Is eDP device:                      false
      I2C address 0x37 (DDC) responsive:  true 
      /sys/bus/i2c/devices/i2c-8/name:   AMDGPU i2c bit bus 0x93
   EDID synopsis:
      Mfg id:           DEL
      Model:            DELL P2411H
      Serial number:    F8NDP11G119U
      Manufacture year: 2011
      EDID version:     1.3
      Product code:     41070
      Binary sn:        825309525 (0x31313955)
      Extra descriptor: 
      Video input definition: 0x80 - Digital Input
      Supported features:
         DPMS standby
         DPMS suspend
         DPMS active-off
         Digital display type: RGB 4:4:4
         Standard sRGB color space: False
      White x,y:        0.313, 0.328
      Red   x,y:        0.631, 0.351
      Green x,y:        0.334, 0.620
      Blue  x,y:        0.156, 0.051
      Extension blocks: 0
   EDID source: 
   EDID hex dump:
              +0          +4          +8          +c            0   4   8   c   
      +0000   00 ff ff ff ff ff ff 00 10 ac 6e a0 55 39 31 31   ..........n.U911
      +0010   04 15 01 03 80 35 1e 78 ea bb 04 a1 59 55 9e 28   .....5.x....YU.(
      +0020   0d 50 54 a5 4b 00 71 4f 81 80 d1 c0 01 01 01 01   .PT.K.qO........
      +0030   01 01 01 01 01 01 02 3a 80 18 71 38 2d 40 58 2c   .......:..q8-@X,
      +0040   45 00 13 2b 21 00 00 1e 00 00 00 ff 00 46 38 4e   E..+!........F8N
      +0050   44 50 31 31 47 31 31 39 55 0a 00 00 00 fc 00 44   DP11G119U......D
      +0060   45 4c 4c 20 50 32 34 31 31 48 0a 20 00 00 00 fd   ELL P2411H. ....
      +0070   00 38 4c 1e 53 11 00 0a 20 20 20 20 20 20 00 63   .8L.S...      .c
   VCP version:         2.1
   Controller mfg:      Mstar
   Firmware version:    1.1
   Monitor returns DDC Null Response for unsupported features: false

Display 3
   I2C bus:             /dev/i2c-10
      I2C address 0x50 (EDID) responsive: true 
      Is eDP device:                      false
      I2C address 0x37 (DDC) responsive:  true 
      /sys/bus/i2c/devices/i2c-10/name:   AMDGPU i2c bit bus 0x95
   EDID synopsis:
      Mfg id:           HWP
      Model:            HP Z22i
      Serial number:    CNC51301ZP
      Manufacture year: 2015
      EDID version:     1.3
      Product code:     12428
      Binary sn:        16843009 (0x01010101)
      Extra descriptor: 
      Video input definition: 0x80 - Digital Input
      Supported features:
         DPMS active-off
         Digital display type: RGB 4:4:4
         Standard sRGB color space: False
      White x,y:        0.313, 0.329
      Red   x,y:        0.647, 0.339
      Green x,y:        0.307, 0.633
      Blue  x,y:        0.146, 0.056
      Extension blocks: 0
   EDID source: 
   EDID hex dump:
              +0          +4          +8          +c            0   4   8   c   
      +0000   00 ff ff ff ff ff ff 00 22 f0 8c 30 01 01 01 01   ........"..0....
      +0010   0d 19 01 03 80 30 1b 78 2e f8 55 a5 56 4e a2 25   .....0.x..U.VN.%
      +0020   0e 50 54 a1 08 00 d1 c0 81 c0 81 80 95 00 a9 c0   .PT.............
      +0030   b3 00 01 01 01 01 02 3a 80 18 71 38 2d 40 58 2c   .......:..q8-@X,
      +0040   45 00 dd 0c 11 00 00 1e 00 00 00 fd 00 32 4c 18   E............2L.
      +0050   5e 11 00 0a 20 20 20 20 20 20 00 00 00 fc 00 48   ^...      .....H
      +0060   50 20 5a 32 32 69 0a 20 20 20 20 20 00 00 00 ff   P Z22i.     ....
      +0070   00 43 4e 43 35 31 33 30 31 5a 50 0a 20 20 00 7c   .CNC51301ZP.  .|
   VCP version:         2.2
   Controller mfg:      Mstar
   Firmware version:    1.0
   Monitor returns DDC Null Response for unsupported features: false

Display 4
   I2C bus:             /dev/i2c-14
      I2C address 0x50 (EDID) responsive: true 
      Is eDP device:                      false
      I2C address 0x37 (DDC) responsive:  true 
      /sys/bus/i2c/devices/i2c-14/name:   card0-DP-2
   EDID synopsis:
      Mfg id:           DEL
      Model:            DELL U3011
      Serial number:    PH5NY2CIANXL
      Manufacture year: 2012
      EDID version:     1.4
      Product code:     16485
      Binary sn:        1095653452 (0x414e584c)
      Extra descriptor: 
      Video input definition: 0xb5 - Digital Input (DisplayPort)
      Supported features:
         DPMS active-off
         Digital display type: RGB 4:4:4 + YCrCb 4:2:2
         Standard sRGB color space: True
      White x,y:        0.313, 0.329
      Red   x,y:        0.678, 0.309
      Green x,y:        0.210, 0.692
      Blue  x,y:        0.146, 0.055
      Extension blocks: 1
   EDID source: 
   EDID hex dump:
              +0          +4          +8          +c            0   4   8   c   
      +0000   00 ff ff ff ff ff ff 00 10 ac 65 40 4c 58 4e 41   ..........e@LXNA
      +0010   33 16 01 04 b5 40 28 78 3a 8d 85 ad 4f 35 b1 25   3....@(x:...O5.%
      +0020   0e 50 54 a5 4b 00 71 4f 81 00 81 80 a9 40 d1 00   .PT.K.qO.....@..
      +0030   d1 40 01 01 01 01 e2 68 00 a0 a0 40 2e 60 30 20   .@.....h...@.`0 
      +0040   36 00 81 91 21 00 00 1a 00 00 00 ff 00 50 48 35   6...!........PH5
      +0050   4e 59 32 43 49 41 4e 58 4c 0a 00 00 00 fc 00 44   NY2CIANXL......D
      +0060   45 4c 4c 20 55 33 30 31 31 0a 20 20 00 00 00 fd   ELL U3011.  ....
      +0070   00 31 56 1d 71 1c 00 0a 20 20 20 20 20 20 01 56   .1V.q...      .V
   VCP version:         2.1
   Controller mfg:      Mstar
   Firmware version:    1.5
   Monitor returns DDC Null Response for unsupported features: false

Options: --enable-usb, --disable-usb

This pair of options controls whether ddcutil searches for displays that use USB for communication. The default is --disable-usb.

Although the overhead of searching for USB displays has a negligable effect on ddcutil performance, the benign error messages it can produce regarding permissions have proven distracting. USB display support is rarely required, as most monitors use DDC/CI, not USB, for MCCS communication.

Option --async

If there are 3 or more monitors and option --async is specified, initial monitor DDC checks are performed in separate threads. marginally improving startup time. (This option may be removed in a future release.)