Pinning LCD display 1601 using microcontroller

Pinning LCD display 1601A:

Pin no.	Symbol	Function
1	Vss	GND
2	Vdd	+ 5V
3	Vo	Contrast Adjustment
4	RS	H/L Register select signal
5	RW	H/L Read/write signal
6	E	H->L Enable signal
7	DB0	H/L Data bus line
8	DB1	H/L Data bus line
9	DB2	H/L Data bus line
10	DB3	H/L Data bus line
11	DB4	H/L Data bus line
12	DB5	H/L Data bus line
13	DB6	H/L Data bus line
14	DB7	H/L Data bus line
15	A	4.2 Volt for LED
16	K	Power for supply B/L (0V)

The CFAH1601AYYBJP is an LCD display with 5×8 character-dot space and 16 character positions and LED (yellow) backlite. It has an industry-standard HD44780 compatible controller chip on the back. An 8-bit or 4-bit parallel interface, and a very wide viewing angle. It operates on +5 Volt, and consumes only 1.2 mA which makes it good for battery usage, but the backlite-LED uses 130 [email protected], so make e.g. a button which activates the backlite, and then automatically let it switch off after three seconds. What also can be done with this display is making your own characters (up to 8 max. by internal RAM, called CGRAM = Character Generator RAM) The ROM consists of the complete ASCII character-set, and also the Japanese/Greek characters, a total of 192 character locations. When using the 4bit interface, you must transmit 2 * 4-bit for each instruction. To let the display operate, it first must be initialized (init procedure) (don’t forget to adjust the contrast (0.8V), else you won’t see nothing. Use a 10k potmeter) I will show both 4- and 8-bit interfaces. 4-bit because it saves 4 i/o’s of the microcontroller. 8-bit because it’s shorter code. Here all features this LCD has:

• Interface with either 4-bit or 8-bit microcontroller.
• Character generator ROM: 192 different 5 x 8 dot-matrix character patterns.
• Character generator RAM: 8 different user programmed 5 x 8 dotmatrix patterns.
• Display data ROM and character generator RAM may be accessed by the microcontroller.
• Numerous instructions: Clear Display, Cursor Home, Display ON/OFF, Cursor ON/OFF, Blink Character, Cursor Shift, Display Shift.
• Built-in reset circuit is triggered at power ON.
• Built-in oscillator (270 kHz)

Next a diagram (4-bit interface) of a CFAH1601AYYBJP LCD display connected to an AT90S1200 microcontroller:

Part list:
1x AT90S1200
1x 1×16 LCD (HD44780)
1x 78L05
1x 4 MHz resonator
1x 47uF/16V
2x 100n multilayer
1x 100n MKH
1x 10k pot
1x 10k
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