With IIC/I2C 2004 20X4 Character LCD Module Display Blue Green ArduinoMega 2560

Other Hardware Displays
1

Hi all

I have problem to get my lcd display to work together with: http://johnny-five.io/api/ API

Is there someone who can help me? :slight_smile:

Best regards Fredrik Hj

2

What kind of trouble? Have you made the LCD to work, by itself, with the examples from the LCD library that you are using?

Read the how to use this forum-please read sticky to see how to, properly, post code and some advice on how to ask a good question.

3

Hi

I have wrote a topic in Swedish at: LCD Display med IIC/I2C 2004 20X4 module och Johnny Five - Scandinavia - Arduino Forum. See the code and the following img. the link, for the stuation as is now!

Best regards Fredrik

4

I'm not familiar with johnny five or node.js but the issue with i2c backpack based LCDs not working is typically comes down to primarily a few things.

  • i2c wiring issue to Arduino (wrong pins or missing pullups)
  • LCD is not wired up to the PCF8574 the way the s/w assumes (not all backpacks are the same)
  • The i2c being used address is incorrect. (different backpacks use different default addresses and/or address ranges)

While it isn't node.js based,
you could install the hd44780 Arduino library and then run the hd44780_I2Cexp i/o class I2CexpDiag tool to determine all your backpack settings.
It will tell you if the i2c signals are working correctly, the i2c address, and the pin mappings used for the backpack.

Then you can look at the node.js LCD code and see if the settings assumed in that LCD module match the specific backpack you have.
If they don't you will have to modify the LCD code to match your specific backpack.

--- bill

5

Hi

That help alot, thank you :slight_smile:

It work now!