Serial 20 x 4 Parallax LCD

[Franklin97355]

I would remove all instances of the Arduino IDE and install 1.6.5 again. Arduino.h is in C:\programdata\arduino-1.6.5-r5\hardware\arduino\avr\cores\arduino\ on my computer.

[K1PL]

I just did that. And I installed Ver. 1.6.7. and Arduino.h is nowhere on my computer. Now the sketches that worked yesterday won't work today. Can't find LiquidCrystalI2C.h It's in the LiquidCrystal Library.

How can I load 1.6.5 ?

Thanks Paul

[Franklin97355]

Get it from here https://www.arduino.cc/en/Main/OldSoftw ... s#previous

[K1PL]

Thanks for the help, I installed 1.6.5 and the shield works.That takes care of the Parallel LCD.
I purchased a SainSmart IIC/I2C/TWI Serial 2004 20x4 LCD Module Shield for Arduino
I went into the SainSmart 2004a site and pulled up the sketch for it.
It is a Serial LCD for the MEGA R3. I have a Arduino UNO. Do I need an R3 to run the 2004A?
Also in the sketch it defines 8 pins, the 2004 used only 2 plus 5 volts and ground. This can't be the right shield for the 2004A.
Where can I find a shield for the 2004A?
Example Arduino sketch for SainSmart IIC/I2C/TWI Serial 2004 20x4 LCD Module Shield For Arduino UNO MEGA R3
#define BACKLIGHT_PIN 3
#define En_pin 2
#define Rw_pin 1
#define Rs_pin 0
#define D4_pin 4
#define D5_pin 5
#define D6_pin 6
#define D7_pin 7

Thanks, Paul

[Franklin97355]

The code here seems to have been tested on the Uno.

Tested on:
Arduino Pro Mini, Arduino Uno - A4 (SDA), A5 (SCL)
Arduino Mega 2560 - 20 (SDA), 21 (SCL)

[K1PL]

Hi,
Thanks for all your help. Finally got the sketch to work with the 2004A.
I didn't try some of the Sketches because of the define statements.
#define En_pin 2
#define Rw_pin 1
#define Rs_pin 0
#define D4_pin 4
#define D5_pin 5
#define D6_pin 6
#define D7_pin 7
Why are there define statements for pins 0 to 7 for a serial LCD that uses only 2 pins?
I tried the sketch you sent me and the first part worked.
It wrote this to the screen 3 times. I2C/TWI BackPack
Then nothing on the screen. In the Sketch it refers to a DS3231 which is a crystal oscillator. where do I find the wiring diagram.

Thanks again, Paul

[Franklin97355]

Why are there define statements for pins 0 to 7 for a serial LCD that uses only 2 pins?

Those are vestiges of the code when connecting directly to the display without the backpack.