Since there is a lot of questions about I2C in e-mails and on the forums, here is a small guide to help.

Q: How do I talk to the display?

A: We use a standard Phillips 7bit address as defined by Phillips. How ever, we at Matrix Orbital specify the I2C address in 8bits. The 8th bit, least significant bit (LSB or Low Order Bit) of the 8bit address is read/write bit. If we take a standard Phillips 7bit address of 45hex this would be in binary 1000101. This is 7bits. If one adds the read write bit to this 7bit address and you assume that you are writing one gets 10001010. Matrix Orbital would describe the Philips I2C address of 45hex as 8Ahex. The read address would be 8Bhex.

Q: How do i read the keypad data?

A: The keypad is read by I

Hello, sorry i don't speak very well English.

I have LCD2041, TTL and I2C MODE. J0 in, J1, J2, J3 OUT, adress i2c : 52H
To write to LCD i send:

Start 1 0 1 0 0 1 0 0 Ack 0 1 0 0 0 0 0 1 Ack Stop

To send A, but i have nothing on the display, and i have Ack error.

Can use i2c inferior has 100Kbs ?

What's the form of trame to send ?

LCD is slave or master I2C ?

Regards.

Hi Lovmy,

Thank you for posting.

Looks like you are not getting an ACK because you are not sending the right address. Try sending 0 1 0 1 0 0 1 0 (0x52) .

You are capable of communicating at a maximum of 100Kbs.

The way to send data to the display is you send the address, then the command or text.

The LCD is always the slave.

The following link is a sample program of using I2C with the unit which can be helpful to you. http://www.lcdforums.com/forums/viewtop ... s&start=15

If you have anymore questions or concerns, please feel free to post.

Best Regards,
:D