Linking two arduinos?

Hello everyone :slight_smile:

I’m really new to Arduino, and I have a project in mind, but I’m not sure it’s something doable.

Bascially, I’d like to make a platform for a rocket model, that would have a small display indicating when is the next launch, what kind of rocket is used, the mission logo and so forth. And 10 seconds before launch, showing a little countdown and at T-0 there would be LEDs on the platform that would light up for a few seconds.

So I recently bought the ELEGOO UNO R3 Project Complete Starter Kit to play around with.

I was planning to use my UNO R3 with a 2.8 Inch TFT LCD, and a ESP8266 wifi connector so that the Arduino could go fetch some data every 30 mn.

But the display takes almost all the pins (leaving 2 digitals and 1 analog apparently), so i was wondering if it was possible to link two arduinos together, with one focused on the display, and the second one one the leds and fetching and processing the data before sending it to the first one? Or is it necessary to take an Arduino Mega?

Thanks in advance for your help!

Couple of notes:

  • For more pins, Google port expander
  • Or, just use a different display
  • If you are new, leave the ESP and wifi for now.

Such displays normally use the three SPI pins and two or three extra. That's it. That leaves you another 14 or so pins on your Uno.

The biggest challenge will be the graphics themselves, considering the 2 kB memory of the Uno. I've never even tried this; my LED is driven by a NodeMCU. More memory to play with, and lots more processing power to actually build up the screen.

Thank you for your tips!

I'll check out what you seuggested, and I'll maybe try a couple intermediate projects before I tackle this one, in order to have more experience.

Have a great day :slight_smile:

use a MEGA, more pins, faster and solves many problems.
you will find the screen response dreadfully slow with an UNO.
the Mega will be much faster.

That must have to do with the memory, as the clock speed of the processor is the same.