Help needed with a 16x2 display

Hardware Nano Family Classic Nano
1

Hi all I wonder if anyone can help

I’m new to Arduino and have a issue I’m unsure of my options

I have started a job due to the last engineer leaving
My issue is the nano is part of a motor controller and wanted to use a 16x2 display with a i2c interface but A4 and A5 are both used

Is there another way of controlling the display ?

Any advice will be greatly appreciated

2

What are they used for? Is this an existing circuit?

3

Hi there both been used for onboard pots for motor speed and at the moment unable to change until a new board can be developed

My only option I have at the moment is a second nano to control the functions of the display and buttons but would have loved to have it the script

So I’m stuck

4

There is a software I2C library. I've never used it, but it may help.

5

Thank you Dave

I will have a read through shortly and thank you again for your time

Simon

6

Interesting idea, but I don't know if any of the i2c LCD libraries will work with it, out-of-the-box. @hollywood2395 might need to change the LCD library extensively to make the idea work.

EDIT: some ideas here

7

Thank you Paul for your advice it’s greatly appreciated I will check it out tomorrow

Kindest regards

Simon

8

It's I2C, you can have many devices attached to A4 and A5 as long as they have different addresses.

9

@sonofcy

Not if one currently uses them as analogue inputs (see post #3).

10

Use the hd44780 library. If you have a PCF8574 based backpack, then use the hd44780_I2Xexp i/o class.
It is compatible with SoftwareWire.
There is even an example of how to use it with SoftwareWire.

--- bill

1 Like
11

One thing to keep in mind is depending on how the motor controller part is handled. The I2C interface software can affect the timing and cause issues. i.e. if the current code depends on specific loop() timing, then using i2c can break that.
--- bill

12

Oops, I missed that, and they didn't plan well.