Re: LCD trouble #ubitx

Arv Evans

First have the LCD upside down.  The connectors are at the top edge of these
displays. The blocks you can see are the top line.  Check the CONTRAST potentiometer
to insure that it can vary the pin-3 voltage from ground to at least 2V.

VSS (Pin-1) is ground.
VCC (Pin-2) is +5V to power the LCD.
VE (Pin-3) is the contrast voltage, usually around 1.1 volts.  Check the pot to insure that it
        is varying the CONTRAST volts on pin-3. 
RS (Pin-4) is driven by the micro-processor to select which register is active.
R/W (Pin-5) should be grounded.  You will only be writing to the LCD.
EN (Pin-6) is driven by the micro-processor to clock data into the LCD register.
DATA-0, 1,2, and 3 (pins 7,8,9 and 10) are not connected because we only use 4-bit mode.
Data-4, 5, 6, and 7 (pins 11, 12, 13, and 14) are used for 4-bit data transfer to the LCD.
Software has to be configured for the above configuration.  Check your LCD setup in software
to insure that the proper micro-controller leads are defined to control the proper LCD leads,
and that the wiring matches that configuration.

Hope that helps.


On Mon, Sep 3, 2018 at 9:49 PM <micah@...> wrote:
uBitx v3 board. I can't get the LCD display working. I've tried two different 1602 modules with the same result. (The second one, white-on-blue, shown below).

It's lighting up. Top row blank, bottom row all squares. Twiddling the blue trimmer pot on the raduino board has no effect whatsoever.

At *just* the right viewing angle, I've been able to make out the text "         = 000 " on the bottom row. The = represents 4 parallel lines, though. Turning the main VFO dial doesn't change the numbers, but clicking it makes the whole display blank out for a second.

Operator error, bad wire-up, defective Raduino, or something else? Thanks! -m

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