Hello everyone,
I'm currently working on a project that involves a Raspberry Touch Display, and I've run into an issue with controlling the brightness of the display panel.
My setup is based on a Qualcomm solution with Android code, but I'm having trouble adjusting the screen brightness using I2C commands with the Raspberry Pi display. After checking the I2C output with an oscilloscope, I found that the second data frame, which should carry the command instruction, is missing, even though I'm entering the command correctly on my computer. This missing second data frame is preventing me from controlling the display brightness through the Android GUI or shell commands.
Interestingly, when I used the same Raspberry Pi display touch panel with a Raspberry Pi 2 Model B board, the I2C commands worked perfectly. The oscilloscope showed that the second data section, where I input the brightness command, was present, allowing me to adjust the display brightness from level 1 to 255 without any issues.
I'm not sure if this problem is due to software differences. Could anyone offer some advice on where I should look next? Thank you!
PC: /backlight/: echo 1 > brigghtness
Qualcomm board I2C scope: [CHIP ID] [ ADDRESS] [MISSING]
Raspberry pi 2 board: [CHIP ID] [ ADDRESS] [0x01 ]
I'm currently working on a project that involves a Raspberry Touch Display, and I've run into an issue with controlling the brightness of the display panel.
My setup is based on a Qualcomm solution with Android code, but I'm having trouble adjusting the screen brightness using I2C commands with the Raspberry Pi display. After checking the I2C output with an oscilloscope, I found that the second data frame, which should carry the command instruction, is missing, even though I'm entering the command correctly on my computer. This missing second data frame is preventing me from controlling the display brightness through the Android GUI or shell commands.
Interestingly, when I used the same Raspberry Pi display touch panel with a Raspberry Pi 2 Model B board, the I2C commands worked perfectly. The oscilloscope showed that the second data section, where I input the brightness command, was present, allowing me to adjust the display brightness from level 1 to 255 without any issues.
I'm not sure if this problem is due to software differences. Could anyone offer some advice on where I should look next? Thank you!
PC: /backlight/: echo 1 > brigghtness
Qualcomm board I2C scope: [CHIP ID] [ ADDRESS] [MISSING]
Raspberry pi 2 board: [CHIP ID] [ ADDRESS] [0x01 ]
Statistics: Posted by madmanx — Thu Nov 07, 2024 1:52 am — Replies 3 — Views 29