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Altera_Forum's avatar
Altera_Forum
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12 years ago

Cyclone V LCD / I2C (baremetal) sample for Altera's SoC DevKit

Hi community,

anybody out there ever programmed the Newhaven LCD on the Altera SoC (Cyclone V) DevKit baremetal?

If I didn't miss something Altera's hwlib doesn't provide support for I2C (not to mention support for the LCD).

As I'm not a linux expert the linux i2c driver isn't very helpfull either.

If someone could give me a hint where to look for a starting point, that would be really great.

Thanks a lot for your support!

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    12 years ago

    Hi,

    I want to give you some hints to get it running.

    it's not very difficult to get it running on a baremetal system. You can still use the hwlib.

    There is a headerfile called alt_i2c.h. This file contains a lot of definitions, needed to implement an i2c driver for your application.

    To write something to the LCD you have to do the following steps:

    first step: you need to write an init-function for the i2c interface. here you have to do the following steps:

    1. Disable the i2c controller by clearing the enabled bit in the alt_i2c_en register

    2. set the controller to master mode (register alt_i2c_con_mst_mod)

    3. set the speed to standard (the newheaven display only supports 100khz clock rate) (register alt_i2c_con_speed)

    4. enable the i2c controller (set enabled bit in the alt_i2c_en register)

    second step: address the slave

    1. write the address of the slave to the alt_i2c_tar register

    third step: the write function:

    1. to send data you have to set the ALT_i2c_data_cmd_cmd Register to WRITE

    2. write the data to the alt_i2c_data_cmd_dat Register

    Now data will be send on the I2C. If you want to implement a full driver you can also check the status register etc. when you send some data...

    Some hints for the newheaven LCD:

    • Slave address is 0x28 (and not 0x50)

    • between the commands you send, you need a delay (normally 100µs).

    • A full list of special commands for the display you can find in the newheaven specification. (Download it from the newheaven website. The LCD is the NHD-0216K3Z)

    I hope it helps you a bit.

    Regards!