So I just got in a nice little LCD package in today - an RT0802B-1 which uses the Hitachi HD44780 standard for Arduino use. The wiring setup is just a bit different for this little unit and I seem to be having problems getting it to work. I am using an embedded Atmega 328 (not on the Arduino development board), but I have hooked the wires up to what I believe are the appropriate pins.
I used this site as a guide for hooking up the LCD. I have used this same diagram before for a 16x2 LCD and it worked fine. I am not getting any response using this little LCD though: http://www.km5z.us/files/arduino-fm/4-bit-LCD_schematic.jpg
The spec sheet for the RT8082B-1 is found on this site:
The only thing I can tell you is that the LCD backlight lights up. I have attached a JPG of how I wired up the pins. I am very much confused on the R/W pin - it is shunted to ground on the first website's wiring diagram, which is how I have it wired on mine.... so I'm not sure if that is correct or not. I guess a fresh set of eyes would be very much appreciated! It is possible that I have all the wires messed up. I don't think that is the case, but if it is can someone please give me some guidance??
Pin 3 is Vo according to the datasheet and should be connected to the contrast pot as shown on the datasheet; whereas you have it connected to +5v. Connecting RW to ground is correct.
When you call the LiquidCrystal constructor in your sketch, do you declare the correct pin numbers and in the right order?
Pin 3 is Vo according to the datasheet and should be connected to the contrast pot as shown on the datasheet; whereas you have it connected to +5v.
If you do not have a potentiometer you could try connecting pin 3 to GND. Many LCD modules work acceptably with pin 3 at 0v but none will give any kind of display when connected to +5v.
dc42 and floresta - thank you both for your input. Somehow I overlooked pin 3 being a ground. I would venture a guess that is my problem since I have been over this and over this.... and yes dc42, I have the correct pins called in the software in the correct order. I ran into that problem last time I used an LCD, so after three wasted days searching for a hardware issues I am now very aware of which pins to call in the software. Haha.
Any insight on what to do with the R/W pin?? Some diagrams do not have it connected to anything, others bring it to ground.
Any insight on what to do with the R/W pin?? Some diagrams do not have it connected to anything, others bring it to ground.
DC42 told you in reply #1 that connecting it to ground was correct. Any diagram that does not connect R/W to anything is wrong. It absolutely must be grounded to send any kind of information to the display and it must be driven high (by software) by any program that attempts to read from the display (most don't).
I have the correct pins called in the software in the correct order.
