Help: NHD-0216S3Z-FL-GBW-V3 python modules for use over i2c

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2 comments

  • falcon

    I've just been using SMBus to send commands directly to i2c, along the lines of what has been attempted here: http://nhdforum.newhavendisplay.com/index.php/topic,2024.0.html

    I can display individual characters occasionally, sometimes these are not the ones requested. I can request to check the baud rate which appears about 5% of the time, and clear the screen, which happens rarely.

    I think I know the answer. The i2c on a lot of these devices, including RPi, Rock64, even Arduino, clocks at around 100 kHz. However the NHD-0216S3Z-FL-GBW-V3 datasheet mentions the maximum clock frequency of 50 kHz! So that explains why the display shows the right characters only occasionally.

    Newhaven dudes, I suspect you might need to increase your i2c clock frequency on this particular LED display module to make it compatible with a wider range of devices.
    One way to test this could be to rebuild an Armbian distribution (or such like) with default i2c clock frequency of 40-50 kHz. Or this might be configurable on the latest Raspberry Pi, by editing the /boot/config.txt file and adding:

    dtparam=i2c_arm=on,i2c_arm_baudrate=50000
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  • Ted M.
    NHD Staff
    Hi Falcon,

    Thanks for your update on this as it sounds like you now have it working with a clock rate of 50 khz.
    The RPLCD Python library looks like a good option to consider using when programming for this character display.

    Best Regards,
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