6 replies to this topic

[Dahsar]

Hello,

I am an engineering student conducting research at a university this summer. In order to progress in this research, I need to develop some program that can interface with the driver to a cd burner so that I can control the laser manually. So before I develop a program that times the laser's movement accordingly, I need some way to communicate with the driver.

Does anyone know how I should go about doing this? Any input would be greatly appreciated.


Thanks!

[WingedPanther]

It will depend a LOT on the driver for the DVD writer. Have you gone to the website of the developer?

[Dahsar]

Currently, I am not sure what computer I will be working with that uses this dvd writer. However, I am sure that I would like to install Linux on whatever computer it is, because it is free of anything proprietary. Before I determine the maker of the writer, is there any further information you can give me so I can get started? Anything in general that can help me achieve this goal?

Thank you,

Rashad

[WingedPanther]

Because the driver will determine what functionality is exposed, that's really the first step. You may be looking at rewriting the driver, or may not even be able to do this.

[Dahsar]

It is a Samsung SH-S182M DVD-ROM. It seems that the previous researcher from last year could not access the writer in the way he wanted, because of security features enabled. Apparently he could not make changes when a cd was not inserted in the drive. He writes on he tried to circumvent this:

"Unable to gain complete control over the DVD-Rom, I then attempted to access from a hardware approach. Primarily, we took the DVD-Rom apart and removed everything useless to us and left only a tray which the laser diode and a motor is mounted to. The purpose for dissembling the DVD-Rom was to allow us to control the system through analogue input (apply voltage/current sources to the laser diode and the motor). To control the laser diode, I used a programmable power supply that provides a voltage potential across the diode’s leads to turn it on and adjust laser’s output power. To control the motor, I purchased a bipolar stepper motor controller from ‘OceanControls Inc’. Finally, I wrote a device driver in labview that communicates with both the programmable power supply and bipolar stepper motor controller through serial ports; this ultimately allows me to control the entire experiment with my computer. "

However, I have no knowledge as to how he used LabView to make a driver to connect to the serial ports. Is it possible that you can create a Linux device driver for serial ports?

Or do you think that these these security mechanisms can be circumvented by using a Linux device driver in the first place?

[WingedPanther]

Dahsar said:

However, I have no knowledge as to how he used LabView to make a driver to connect to the serial ports. Is it possible that you can create a Linux device driver for serial ports?

I can almost guarantee the answer to this is yes.

Dahsar said:

Or do you think that these these security mechanisms can be circumvented by using a Linux device driver in the first place?

That depends on the hardware. If the DVD-Rom has the security mechanisms in the firmware, no. If they are in the driver, then you may be able to open the driver and remove them.

[Dahsar]

I have been reading numerous literature concerning Linux device drivers and how to develop them. However, after gaining some understanding as to what a serial port device driver is and what categories they go under (character device drivers, more specifically ttyS device drivers), I began to contemplate why would I need to develop a device driver unique to this setup if it is simply following the protocol of a standard serial port? Wouldn't I simply have to call the device driver for serial ports in linux to get a signal sent through? If so, how would I go about calling the driver?

Thanks,

Dahsar