How to access PWM back light driver? - arm

I am using iMX6Q SD board. And I have to access the back light driver to control back lite contrast. How can I access from User space or Kernel space? (Back light PWM driver path is drivers/video/backlight/pwm_bl.c). Thanks in advance.

sysfs is the interface for the misc drivers.

Related

Using I2C on XMC1100 2Go

I recently got the Infineon 3D Magnetic Sensor 2Go development board (based on the XMC1100 microcontroller) and I would like to know how to read input from the 3D Magnetic Sensor which is interfaced through I2C. I am new to the Infineon development system, so I do not know how to gather and process input from the sensor.
Here is what I know so far:
The main microcontroller is an Infineon XMC1100-Q024F0064
The 3D Magnetic Sensor is connected to the XMC1100 via I2C
How to program and control the GPIO on the XMC1100
How to use the supplied stand-alone applet to view data from the Sensor
I have the DAVE IDE, the APPs extension, and I am writing my code in C. I need to use DAVE to accomplish my desired end result, but I would be interested to know the Arduino method as well.
Thank you in advance for your help!

USB driver for STM32l100rc using HAL library

Is there anyone who has worked on STM32L1 series. I'm working on STM32L1xx series and wanted to write USB driver for it. Is there any example for USB driver for STM32L series or anyone worked on STM32L1xx series? Any help will be appreciated.
Thanks in advance.
You need these works to do:
1.USB client driver on STM32. There are lots of available codes in github or other website;
2.SDcard driver. Normally SDCard has two modes, include SPI mode and SD mode, the operation will be simplified a lot in SPI mode, however, in SD mode the speed will more faster than SPI mode. you can refer to datasheet for more information.
Download STM32CubeMX
Download STM32CubeL1
Start new project for your device, choose peripheral, choose device class for MSC
Setup clock for USB
Export project
Configure SPI for your SDCARD (SDIO is not available) for interface between USB device stack and SDCARD sector read on PC demand.
This are key steps to do, as I don't know what you know so far (looks like nothing) and what you have learn yourself so far (looks like nothing) I'm unable to give you comprehensive answer.

Serial Port Terminal

I am programming a MAX32 Micro controller in MPLAB. I want to use the UART protocol to interact with my terminal (I am developing on a mac). Is this possible? Can someone point me in the right direction to get started?
Read Wikipedia UART Article
Read Reference Manual of your µC, Chapter "...UART..."
Get example Code for this issue from your Reference Manual or Programming Manual or Internet Articles
Program your board
Connect your Board with your PC via Cable (USB, RS232 to USB (virtual RS232) or UART to USB)
Open Terminal Program i.e. TeraTerm
Check your Settings i.e. Baud Rate
Try it

Arduino computer mouse/input device

I have successfully talked to the computer from an Arduino via serial USB port and I had the idea that I could make a keyboard or mouse with the arduino. Say I wanted to translate the computer's mouse 1 pixel to the left. What message would I have to send over the serial line in order to achieve this?
Google is a wonderful thing. "use arduino as mouse" returns 1.7 million hits. The third hit on the list takes you to the Arduino Playground for an example using the new Leonardo board.
Note:
The Leonardo differs from all preceding boards in that the ATmega32u4 has built-in USB communication, eliminating the need for a secondary processor. This allows the Leonardo to appear to a connected computer as a mouse and keyboard, in addition to a virtual (CDC) serial / COM port.
Assuming you don't have that board, here is another site for some other specific boards and yet another that is log for a project including hardware and software for older boards.
Hope this helps (and is a better answer to the question).
You would have to reconfigure the USB interface chip to appear as a USB HID endpoint.

How to set system time in a Windows WDM driver?

We are developing a GPS time sychronization hardware device. And we want write a Windows WDM driver for the device. To avoid the user level latency, we'd like set windows( XP/Vista/7) system time in the kernel driver level. Does anyone know how to achive that?
Thanks
Xu Jun
Did you try NtSetSystemTime? I think it's undocumented.
http://undocumented.ntinternals.net/
See also http://undocumented.ntinternals.net/UserMode/Undocumented%20Functions/Time/NtQuerySystemTime.html
Yyou should use the Zw-prefix functions in your driver.

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