i2c linux smbus - how to verify that the address of the lcd?

[superfrog]

what kind of initialization code do I need to interface between an ARM uP and the LK204-25 using i2c? I changed the jumper settings to i2c in lcd hardware, and connected the power, ground, i2c clk and i2c data lines to the uP.

Using the smbus protocol in linux, i changed the slave address to 0x50, and sent the clear screen command, but nothing happens. I see the 0x50 being transmitted while monitoring on the oscope, but the ninth bit it a nack.

how do i verify that the address of my lcd is 0x50?

thanks.

[Clark]

Hi Superfrog,

Thanks for the question, sorry to hear that you have been unable to successfully communicate to your LK204-25 using I2C. It sounds like the module is not responding to the 0x50 address you are expecting.

What you may want to try is the manual override procedure outlined in section 2.6 of your manual. This will force the I2C address to 0x50, and should allow communication with the device. It should also be noted that this will turn the auto RS232 reply function on, which means it will have to be turned off to receive data such as key presses from the display.

Let me know if that improves the situation.

Thanks,
Troy