The display is divided into 4 sections, each with 8 characters.
The bottom right is the menu. The top right is the output.
The uPD 7228G is more like a graphics display than the HD44780a, and each column of pixels can be written to.

Each character is 7 pixels high by 5 pixel wide plus a row for the cursor.

My LogiPic was an application to use a surplus EA-N 16025 AR display.

It samples the PIC’s A-port and puts the bits onto the display a column of pixels at a time.

The display uses a pair of NEC uPD 7228G. A later version of the chip is the uPD16434. It does not use the popular HD 44780a chip.

The LogiPic samples the PIC’s A-port and puts the bits onto the display, a column of pixels at a time. If you use the HD44780A based chip, you would need to use the 8 redefinable characters to form an 7 pixel high by 40 pixel wide graphics display.

You would need to take five samples and rotate them from vertical to horizontal and program the corresponding definable character in the HD44780A. Display characters with codes 0 to 7 from left to right.

The edg button cycles around the trigger options:

C, C_--, S, C_--, FREQ, ,Count, Time

Where C means continuous, and S means single, and _-- means wait for edge on PA0. Freq measures freq of signal on PA4. Count counts the presses of trig, Time does nothing.

Copyright, D H Rice, 2003.
doug.h.rice@btinternet.com