If the device is not received, after using VNC login, the display resolution is very small, should be 480p, resulting in a very inconvenient use.
By modifying the/boot/config.txt file, the desktop can also be displayed at a set resolution when the monitor is not connected. Here's how:
1. Open Config.txt File
Method One: Use the SD card reader to open the Config.txt file in the boot folder in the Windows environment
Method Two: After entering the raspberry system, use the VI Editor: sudo vi/boot/config.txt
2. Modify the following parameter values in the Config.txt file
hdmi_force_hotplug=1 #即便没有检测到HDMI显示器也要使用HDMI模式
hdmi_drive=2 #HDMI模式 (will have sound output if supported and enabled)
hdmi_group=2 #使用DMT格式
hdmi_mode=16 #DMT格式下的屏幕分辨率
Config.txt file Parameters Detailed description refer to this article:
Http://shumeipai.nxez.com/2015/11/23/raspberry-pi-configuration-file-config-txt-nstructions.html
Note: The specific resolution configuration is described below
Hdmi_mode Setting the screen resolution
when Hdmi_group=1 (CEA), the following values are validHdmi_mode=1 VGA
hdmi_mode=2 480p 60Hz
hdmi_mode=3 480p 60Hz H
Hdmi_mode=4 720p 60Hz
Hdmi_mode=5 1080i 60Hz
Hdmi_mode=6 480i 60Hz
hdmi_mode=7 480i 60Hz H
Hdmi_mode=8 240p 60Hz
Hdmi_mode=9 240p 60Hz H
hdmi_mode=10 480i 60Hz 4x
hdmi_mode=11 480i 60Hz 4x H
hdmi_mode=12 240p 60Hz 4x
hdmi_mode=13 240p 60Hz 4x H
hdmi_mode=14 480p 60Hz 2x
hdmi_mode=15 480p 60Hz 2x H
Hdmi_mode=16 1080p 60Hz
Hdmi_mode=17 576p 50Hz
Hdmi_mode=18 576p 50Hz H
hdmi_mode=19 720p 50Hz
HDMI_MODE=20 1080i 50Hz
Hdmi_mode=21 576i 50Hz
hdmi_mode=22 576i 50Hz H
hdmi_mode=23 288p 50Hz
hdmi_mode=24 288p 50Hz H
hdmi_mode=25 576i 50Hz 4x
hdmi_mode=26 576i 50Hz 4x H
hdmi_mode=27 288p 50Hz 4x
hdmi_mode=28 288p 50Hz 4x H
hdmi_mode=29 576p 50Hz 2x
hdmi_mode=30 576p 50Hz 2x H
HDMI_MODE=31 1080p 50Hz
HDMI_MODE=32 1080p 24Hz
Hdmi_mode=33 1080p 25Hz
HDMI_MODE=34 1080p 30Hz
hdmi_mode=35 480p 60Hz 4x
hdmi_mode=36 480p 60Hz 4xH
hdmi_mode=37 576p 50Hz 4x
hdmi_mode=38 576p 50Hz 4x H
hdmi_mode=39 1080i 50Hz Reduced blanking
HDMI_MODE=40 1080i 100Hz
HDMI_MODE=41 720p 100Hz
hdmi_mode=42 576p 100Hz
hdmi_mode=43 576p 100Hz H
hdmi_mode=44 576i 100Hz
hdmi_mode=45 576i 100Hz H
hdmi_mode=46 1080i 120Hz
hdmi_mode=47 720p 120Hz
hdmi_mode=48 480p 120Hz
hdmi_mode=49 480p 120Hz H
Hdmi_mode=50 480i 120Hz
hdmi_mode=51 480i 120Hz H
hdmi_mode=52 576p 200Hz
hdmi_mode=53 576p 200Hz H
hdmi_mode=54 576i 200Hz
hdmi_mode=55 576i 200Hz H
hdmi_mode=56 480p 240Hz
hdmi_mode=57 480p 240Hz H
hdmi_mode=58 480i 240Hz
hdmi_mode=59 480i 240Hz H
H represents 16:9 scale (normal is 4:3).
2x means double pixels (that is, a higher pixel time pulse, two repetitions per pixel)
4x represents four times pixels (i.e. higher pixel time pulse, four repetitions per pixel)
when hdmi_group=2 (DMT), the following values are validWarning: Pixel time pulse is limited, the highest supported mode is 1920x1200 @60hz with reduced blanking.
Hdmi_mode=1 640x350 85Hz
hdmi_mode=2 640x400 85Hz
Hdmi_mode=3 720x400 85Hz
hdmi_mode=4 640x480 60Hz
Hdmi_mode=5 640x480 72Hz
Hdmi_mode=6 640x480 75Hz
Hdmi_mode=7 640x480 85Hz
Hdmi_mode=8 800x600 56Hz
Hdmi_mode=9 800x600 60Hz
hdmi_mode=10 800x600 72Hz
hdmi_mode=11 800x600 75Hz
hdmi_mode=12 800x600 85Hz
Hdmi_mode=13 800x600 120Hz
Hdmi_mode=14 848x480 60Hz
hdmi_mode=15 1024x768 43Hz Don't use
hdmi_mode=16 1024x768 60Hz
hdmi_mode=17 1024x768 70Hz
hdmi_mode=18 1024x768 75Hz
hdmi_mode=19 1024x768 85Hz
hdmi_mode=20 1024x768 120Hz
Hdmi_mode=21 1152x864 75Hz
Hdmi_mode=22 1280x768 Reduced blanking
hdmi_mode=23 1280x768 60Hz
hdmi_mode=24 1280x768 75Hz
Hdmi_mode=25 1280x768 85Hz
Hdmi_mode=26 1280x768 120Hz Reduced blanking
hdmi_mode=27 1280x800 Reduced blanking
hdmi_mode=28 1280x800 60Hz
hdmi_mode=29 1280x800 75Hz
hdmi_mode=30 1280x800 85Hz
hdmi_mode=31 1280x800 120Hz Reduced blanking
Hdmi_mode=32 1280x960 60Hz
hdmi_mode=33 1280x960 85Hz
hdmi_mode=34 1280x960 120Hz Reduced blanking
Hdmi_mode=35 1280x1024 60Hz
hdmi_mode=36 1280x1024 75Hz
hdmi_mode=37 1280x1024 85Hz
hdmi_mode=38 1280x1024 120Hz Reduced blanking
hdmi_mode=39 1360x768 60Hz
hdmi_mode=40 1360x768 120Hz Reduced blanking
hdmi_mode=41 1400x1050 Reduced blanking
hdmi_mode=42 1400x1050 60Hz
hdmi_mode=43 1400x1050 75Hz
hdmi_mode=44 1400x1050 85Hz
hdmi_mode=45 1400x1050 120Hz Reduced blanking
hdmi_mode=46 1440x900 Reduced blanking
hdmi_mode=47 1440x900 60Hz
hdmi_mode=48 1440x900 75Hz
hdmi_mode=49 1440x900 85Hz
Hdmi_mode=50 1440x900 120Hz Reduced blanking
hdmi_mode=51 1600x1200 60Hz
hdmi_mode=52 1600x1200 65Hz
hdmi_mode=53 1600x1200 70Hz
hdmi_mode=54 1600x1200 75Hz
Hdmi_mode=55 1600x1200 85Hz
hdmi_mode=56 1600x1200 120Hz Reduced blanking
hdmi_mode=57 1680x1050 Reduced blanking
hdmi_mode=58 1680x1050 60Hz
hdmi_mode=59 1680x1050 75Hz
hdmi_mode=60 1680x1050 85Hz
hdmi_mode=61 1680x1050 120Hz Reduced blanking
hdmi_mode=62 1792x1344 60Hz
hdmi_mode=63 1792x1344 75Hz
hdmi_mode=64 1792x1344 120Hz Reduced blanking
hdmi_mode=65 1856x1392 60Hz
hdmi_mode=66 1856x1392 75Hz
hdmi_mode=67 1856x1392 120Hz Reduced blanking
hdmi_mode=68 1920x1200 Reduced blanking
hdmi_mode=69 1920x1200 60Hz
Hdmi_mode=70 1920x1200 75Hz
hdmi_mode=71 1920x1200 85Hz
hdmi_mode=72 1920x1200 120Hz Reduced blanking
hdmi_mode=73 1920x1440 60Hz
hdmi_mode=74 1920x1440 75Hz
hdmi_mode=75 1920x1440 120Hz Reduced blanking
hdmi_mode=76 2560x1600 Reduced blanking
hdmi_mode=77 2560x1600 60Hz
hdmi_mode=78 2560x1600 75Hz
hdmi_mode=79 2560x1600 85Hz
hdmi_mode=80 2560x1600 120Hz Reduced blanking
hdmi_mode=81 1366x768 60Hz
hdmi_mode=82 1080p 60Hz
hdmi_mode=83 1600x900 Reduced blanking
hdmi_mode=84 1920x1200 Reduced blanking
hdmi_mode=85 720p 60Hz
Hdmi_mode=86 1366x768 Reduced blanking
I use the mirror 2017-01-11-raspbian-jessie.img
Raspberry Raspberry Pi Learning notes-display resolution configuration