This is a module to give my robot TIM-01 Eyes.

With many projects controlled by an Arduino or similar microcontroller, the number of pins soon become in short supply.

So when it came to designing some eyes for my robot, I wanted to use the Nokia 5110 screens, but wanted to control them with as few wires (pins) from the controller as possible.

As all the other modules on my robot are connected to each other via I2C (two wire) bus, I decided to make this module do the same.

It has a pin expander incorporated to control the two screens.

I also wanted better backlighting, so there is also provision to add two intelligent RGB LEDs (SK9822).

The Arduino NANO I2C has 5 volt data lines.

As the Nokia screens are 3.3v there is a 3.3v regulator and data voltage changers.

NOTE!

There are two types of Nokia Screen for sale on eBay, this is designed for the screens sold without a brake-out board.

The difference between the two are:

• Those that come on a break-out board have eight pins on the back side.
• The ones for this board have a rubber Zebra-Strip on the back side, this type has 9 connections.

It should have in the ID, LPH7366

I have done an Arduino library for this module, there is a link to the source.

There is a link to the main documentation of my robot, showing more details on how I made it.

Here is a video showing what I was aiming for:

Not all the components need to be added to the PCB.

I have designed it so that it can be used in more than one way:

1. All components on the back side to use with I2C.
2. I have made provision so that four small LEDs on each Eye can be used like on the break-out boards sold.
3. I have made provision for headers so that connections can be made direct to the screens and use SPI to control them. Only one capacitor on each eye needs to be added to front of the board in this configuration. (I have not made Arduino library for SPI)

Of course this will work for any project you want to have eyes on and control via I2C.

The overall width is 100mm so can be ordered as a prototype.