library is very sensitive to timings

[nahuel]

If you run the isolated tests, this library works ok. But if you integrate it in a node process running other stuff, then you get very erratic results. For example (using npm install sleep):

var Lcd = require('lcd')
var sleep = require('sleep')
var lcd = new Lcd(
            {rs: 26,  
             e: 44,  
             data: [66, 67, 69, 68], 
             cols: 20, 
             rows: 4});
lcd.setCursor(0,0)
lcd.print('Hello', () => {})
sleep.sleep(3)  // simulate other stuff running in the node process

When you run this on a Beaglebone Black with a SHENZHEN 2004A Display, you get only the last o character printed at the 0,0 position. If you remove the sleep line, the snippet works ok.

[fivdi]

I can't figure out what the problem is by looking at the code and will need to build a circuit to try and reproduce the problem.

[fivdi]

As mentioned in the documentation an Lcd object will emit a ready event when the display is ready for usage. The usage example shows how to use the ready event. An Lcd object should not be used before the ready event is emitted.

Something like this should work:

var Lcd = require('lcd')
var sleep = require('sleep')
var lcd = new Lcd(
            {rs: 26,  
             e: 44,  
             data: [66, 67, 69, 68], 
             cols: 20, 
             rows: 4});
lcd.on('ready', () => {
  lcd.setCursor(0,0)
  lcd.print('Hello', () => {})
  sleep.sleep(3)  // simulate other stuff running in the node process
});

[fivdi]

I'm going to go ahead and close this issue as it doesn't appear to be an issue with the lcd module. If it turns out that it is an issue with the lcd module the issue can be reopened.