I set E, RW low and RS stays low to write commands (setting mode to 1 means RS low, if mode sees a 0 then RS sees a 1 and thats when we write to DDRAM), then E goes high, data gets pushed through and then E goes low and high...this is how I read it. I hope that is correct.
That makes absolutely no sense at all and is very likely to damage the display. The contrast pin is V5, not Vdd.
QuoteThat makes absolutely no sense at all and is very likely to damage the display. The contrast pin is V5, not Vdd.What doesn't make sense?When you are running the device from a 5 volt supply the supply voltage for the controller is 5 volts above GND and the supply for the LCD (frequently called the contrast voltage) is 4.4 volts below that (at 25C). This puts the contrast pin at 0.6 volts above GND.When you are running the device from a 3.3 volt supply, and if the contrast voltage is still 4.4 volts (or so) below that, then the contrast pin must indeed be negative with respect to GND. I don't think there is any reason to suspect that this may harm the device as it is quite normal for an LCD to require a negative contrast voltage, especially those designed to run at low temperatures.Don
All voltage values are referenced to GND = 0VV1 toV5, must maintain VDD ?V1 ?V2 ?V3 ?V4 ?V5?GND.(my emphasis)
In a 3.3v environment, you will need to create a negative voltage (-1v or more) and apply it to the contrast pin (Vdd in your case).
QuoteAll voltage values are referenced to GND = 0VV1 toV5, must maintain VDD ?V1 ?V2 ?V3 ?V4 ?V5?GND.(my emphasis)V5 is the contrast voltage for this display and the data sheet specifically calls for it to be positive with respect to ground.