Hi Don,
It has been quite a while. Apologize for the very long hiatus and am hoping that you haven't given up on me here.
Anyhow, since we last communicated I have since tried to get the 20x4 noritake vacuum fluorescent display (CU20045-UW5A) to work, using an uno, a 2560 and now a Ruggeduino (equvlt. to uno). I’ve come up with lots of code, also utilizing the routines for the data write and command write that was obtained on the last occasion, together with delays in the init routine I believe should work, uploaded the adjusted program and still the display does not respond. With this code I just obtained a line of pixels on the LCD. I've recently used modified code from the arduino site for 8 bit mode operation and also incorporated the ‘positional’ feature for placing text data, obtained from source code from the AVR text by Mazidi. This ;combinational' script compiles, uploads and displays information on the 16x2 LCD very well.
Checked the timing diagrams for the uploaded data on a 16 input logic analyzer looking at when and how data is written relative to the enable and RS, RW pins for the LCD, simultaneously linking the circuit to the vfd which did not respond. The diagrams sort of made sense in that I can see data being written when the LCD enable pin in pulsed and RS is low, when the schematic is captured. I altered the delay times between each instruction in accordance with the max times that each instruction should take, and have not exceeded them, compared to those used for the LCD, bearing in mind that the vfd processes information faster than the LCD as shown by the data sheet for the vfd. That said I'm thinking bigger delay times should bring responding as the LCD. Would this have anything to do with altering the timer counter register data structure and prescalar in one of the timer libraries?
I have even tested the vfd grid pins to see if the thing is even working and of the 9 grid pins emanating from the bottom of the display the middle 7 lit up the grids very well, the end 2 nothing! The end filament pins, were hooked up to 3V supply, with a 14V common negative, and the positive end of the 14v supply checking each grid pin.
Any suggestions as to what I should read up to point to the solution to this problem would be greatly appreciated at this 11th hr.
Thanks.
P.S: Just have the wires hooked up as I have for testing purposes now, but once program writes, and the display responds, next step would be to alter the program for the display format, interface a keypad to the arduino for the program, and neatly and compactly integrate display, MCU and keypad within the encasing.