Can't get Grove LCD Twig to work

[jimbo.we]

@gigamegawatts

I had the same problem as Bill initially. I had to change a couple of things in order for the LCD Demonstration program in the Grove documentation to work (garden.seeedstudio.com/index.php … onstration)

1. The contrast needed to be changed from the default setting. There is a small potentiometer for this, on the LCD’s “stem”, marked R1. If you don’t see some “block” characters on the first line when you initially plug in the Arduino, then the contrast probably needs to be adjusted.

2. I’m not sure if I downloaded the wrong LiquidCrystal library from Seeed’s site, but the one I have (from seeedstudio.com/depot/images … rystal.rar) isn’t compatible with the sample code in the Grove documentation. There isn’t a constructor that takes only 6 parameters, and there isn’t a begin function.

So, I connected a 4th cable to the upper right connector on the LCD stem, and plugged it into the D11/D12 connector on the Grove shield. I changed the constructor and begin function in the sample code to:

//LiquidCrystal lcd(1,2,3,4,5,6);
LiquidCrystal lcd(5,11,6,7,8,9,10); // pin 11 is RW

void setup()
{
//lcd.begin(8,2);
}

By the way, the connectors on the LCD stem are labelled on the back of the stem board. The upper right one is for RW, and the two on the top side of the stem are only used for 8-pin LCD connections (which require 4 more parameters in the LiquidCrystal constructor).

Dan.

The LiquidCrystal lib has its problem, so change the pins may cause problem at my practice.