NHD-C12832A1Z-FSW-FBW-3V3 won't initialize

YanEngine

For a project with a simple PIC18 processor I'm trying to use the COG-LCD Display NHD-C12832A1Z-FSW-FBW-3V3. I've connected the display and the capacitors as mentioned in the datasheet and used the example code for this specific LCD from the Newhaven homepage.  According to the datasheet, I can use every capacitor type as long as I'm still in the range. But it doesn't work (the LCD doesn't react to the init code) and I can't figure out why. I also tried sending the same commands via SPI, but nothing.
In another topic I've read something about the voltage booster circuit not being properly activated. I measured V_out and it's only at 2.9 V. Voltage V0,...,V4 are also to small, I measured only a few mV. I know this is to low for the LCD to work.
This raises my question: How do I know I activated the voltage booster circuit correctly?
Or: How do I know that the voltage booster circuit is working properly besides measuring the voltage?
Does the voltage booster circuit work as long as my capacitors and the connections are correct or does it depend on the initializion code I'm sending to the driver/ the LCD? 

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Comments

5 comments

Date Votes
  • Alee_S

    Hello YanEngine,
    Sorry to hear you are experiencing trouble with the NHD-C12832A1Z-FSW-FBW-3V3 display.

    The initialization routine does affect the generated Voltage for the LCD glass to an extent, but the construction of the voltage booster circuit is more important in this regard, and the best way to verify its operation would be to measure the voltage at V_out and V1-4 pins. We measured the V_out pin to measure about 9.3V on one of our units for reference, and the value you should expect to see.

    We typically use non-polarized ceramic SMD capacitors in our test fixtures and for our prototype board NHD-PCB12832A1Z, as these provided the best results consistently. We have also found polarized electrolytic capacitors to pose some issues in properly activating the voltage booster circuit correctly. Please share more details on the capacitor type and values used for this setup.

    Can you also share if you have more than 1 display to test and if this occurs across more than 1 unit? Has the display been soldered down to a PCB or connector, and are these connections stable? Or is the display pins simply leaning against a set of metal thru-hole to establish a contact connection?

    I've also linked some example code below for your reference as needed:

    https://support.newhavendisplay.com/hc/en-us/articles/4415264814231-NHD-C12832A1Z-with-Arduino

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  • YanEngine
    Hello Alee_S,

    thank you for the fast reply.
    OK, what I get from your reply is the fact that my connection for the voltage booster circuit may be faulty.

    I created a simple PCB to extend the pins for a connection to a breadboard. I tested all the connections and these are stable. Regarding the capacitors: I connected these via through hole. I also have a second display, but the second one isn't soldered to a PCB yet.

    I have some ceramic SMD capacitors at my disposal, so I'm going to try that next. In case that doesn't fix anything, I try with my second display.
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  • Alee_S
    Hi YanEngine,
    Thanks for the response.

    Will stay tuned for your next update. Feel free to provide any images of your test setup or the display's behavior during this process if you feel it will be helpful.

    Best,
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  • YanEngine
    Hi Alee_S,

    I tried several things. First I used 1uF ceramic SMD capacitors for all eight capacitors. After that I used 0.1uF for C1 through C5. I got the same result as before, nothing changed.
    After that, I verified with my second LCD, the same problem occurs.
    I've used the exact same setup as the NHD-PCB12832A1Z.

    Nothing changed and I'm all out ideas
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  • Alee_S
    Hi YanEngine,

    I sent you an e-mail yesterday in order to obtain further information regarding your setup. Please contact me on that channel in order to troubleshoot and resolve this issue.

    Best,

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