LCD Display Being Fickle

I'm working on a project for a laser tag game that I'm trying to migrate from using an Arduino board prototype to individual components so I can eventually create a PCB. This will be my very first project to become its own PCB, I hope. I'm using this Jameco Arduino on a breadboard tutorial to guide me.

One snag I'm hitting is with the LCD screen I'm using which seems to work when plugged into the Arduino, but when I take the exact same chip and put it into the "Arduino on a breadboard" design, I'm getting nothing. I've made a demonstration video here: - YouTube

I don't think any of the other components are causing the problem, but I'll remove them next and try without anything else in the circuit. I'm just curious if someone can look at the "Arduino on a breadboard" project and tell at a glance that I'm doing something stupid like using the wrong power or ground pins, or something like that, because I've checked and re-checked all the connections from the LCD screen to the chip, and I can't find any issues. Thank you very much in advance to anyone who can give me some things to try, or some ideas about what's going wrong!

Are you certain that the Uno chip is running the program when plugged into the solderless board?

Your video does not CLEARLY show the connections from the MCU to the LCD. A photograph that we can zoom into would be much easier to check out, especially if you use different colored jumpers instead of all the same.
A photograph of the UNO board connections will also help, along with the Sketch that is loaded into the MCU.

Hi,
You don't know if your protoboard version is actually running.
Place a LED and resistor to the pin13 on your protoboard, like there is on the UNO board.

Load the "Blink without delay" example into the 328 and make sure the UNO board LED flashes.
Then move the 328 to your protoboard to see if its pin13 LED flashes.

In this situation it is a good idea to use the pin13 LED as a "heartbeat" LED to show your 328 is running with your main code.

Hope this helps.. Tom.. :slight_smile:

Load the "Blink without delay" example into the 328 and make sure the UNO board LED flashes.
Then move the 328 to your protoboard to see if its pin13 LED flashes.

In this situation it is a good idea to use the pin13 LED as a "heartbeat" LED to show your 328 is running with your main code.

Well, you were right about the protoboard isn't running as expected, but the behavior is very strange. The sketch I loaded seems to be working at least in part. I have 4 LED's that you can see in the video that are turned on by the DIP switch just above them. Those are running on A5, A4, A3, and A2 as digital pins with no problem. When I use the DIP switch, each LED comes on as expected.

However, when I load the BlinkWithoutDelay sketch, an LED attached to D13 doesn't blink. So, clearly something isn't working right. I'm going to try and remove all the other components I have, and try to get just the LCD display working with the breadboard Arduino. Thanks for the tip.