System DPI¶
This chapter describes how to modify the screen density (DPI) of the Android system to adapt to displays of different resolutions.
Default DPI and Configuration Files¶
The DPI configuration files and default values for each board are listed below:
| Model | SoC | SDK | Default DPI | Configuration File |
|---|---|---|---|---|
| K1 / K1B | RK3568 | rk-android13.0 | 200 | device/rockchip/rk356x/rk3568_t/rk3568_t.mk |
| K1 MINI | RK3568 | rk-android13.0 / rk-android14.0 | 200 | device/rockchip/rk356x/rk3568_t/rk3568_t.mk |
| K2B / K2C | H618 | h618-android12.0 | 200 | device/softwinner/apollo/apollo_p2.mk |
| K3 | RK3562 | rk-android13.0 | 200 | device/rockchip/rk3562/rk3562_t/rk3562_t.mk |
| K3B | RK3562 | rk-android13.0 / rk-android14.0 | 200 | device/rockchip/rk3562/rk3562_t/rk3562_t.mk |
| K5 / K5C | A133 | a133-android10.0 | 160 | android/device/softwinner/ceres-c3/ceres_c3.mk |
| K7 / K7C / K7S_F | RK3576 | rk3576-android14.0 | 200 | device/rockchip/rk3576/rk3576_u/rk3576_u.mk |
| K8 | RK3588 | rk-android13.0 | 200 | device/rockchip/rk3588/rk3588_t/rk3588_t.mk |
| K8D | RK3588S2 | rk-android13.0 / rk-android14.0 | 280 | device/rockchip/rk3588/rk3588s_t/rk3588s_t.mk |
| K9 | T527 | t527-android13.0 | 160 | device/softwinner/saturn/t527-demo/device-common.mk |
| K10B | A733 | a733-android13.0 | 160 | device/softwinner/jupiter/a733-demo-aiot/device-common.mk |
| K11C | RK3566 | rk-android13.0 / rk-android14.0 | 200 | device/rockchip/rk356x/rk3566_t/rk3566_t.mk |
| TX66 | RK3566 | rk-android13.0 | 200 | device/rockchip/rk356x/rk3566_t/rk3566_t.mk |
Modifying the Source Code¶
Modify the ro.sf.lcd_density property value in the corresponding configuration file. Taking K1 (RK3568) as an example:
--- a/device/rockchip/rk356x/rk3568_t/rk3568_t.mk
+++ b/device/rockchip/rk356x/rk3568_t/rk3568_t.mk
@@ -40,7 +40,7 @@
## add Rockchip properties
#
-PRODUCT_PROPERTY_OVERRIDES += ro.sf.lcd_density=200
+PRODUCT_PROPERTY_OVERRIDES += ro.sf.lcd_density=120
PRODUCT_PROPERTY_OVERRIDES += ro.wifi.sleep.power.down=true
PRODUCT_PROPERTY_OVERRIDES += persist.wifi.sleep.delay.ms=0
For other boards, modify the corresponding configuration file listed in the table above. After modification, recompile and flash the firmware.
Temporary Modification via Command Line¶
You can also change the DPI temporarily via command line (the change takes effect immediately but resets to the default value after reboot):
To make the change permanent, you need to modify the corresponding configuration file and recompile and flash the firmware.