Light Sequence Creator with LCD Display Uno R3 and 74HC595 chip-Communication Issue

@mr-owl

I see you are doing an illuminating dive into electronics and programming. 😀

I fear I cannot bring too much light to bear on you project but I can say how I approach projects that I've grabbed from the net that don't appear to work at first. 

And that is to break everything down into small steps.  For example maybe you disconnect all your electronics except the LED's.   Then you write of copy a bit of code to do something with those LED like make them flash in sequence.  This will at least validate the wiring to the LED's.  And then move on to do something simple with your LCD, again to validate all the connections and the programming logic, at least for simple steps.

For the code you downloaded, start by identifying small bits of the code that appear to do something you recognise and just copy that code or comment out all the other bits for now  /*  xxx */  and see if you can get the code snippet to run.    If you are not familiar with platform IO and C++ to flash your arduino then don't forget you can copy/past the C++ code into the Arduino environment and compile it from there.

Have a nice cup of tea between the small steps helps too. 😎  

@ byron

 I switch out the  Uno R3  I just  purchased , put in my old uno broad  and all the LED s came on  so my circuit is okay  and board communicates  except for the LCD display 

I tested my LCD display with a simple  " Hello  World " program and except for power , no data pin communication - I did solder pins in  and may have damaged the display - I ordered  another one with pins 

There is a definite problem with the display so I'll see what happens when I put the new one in 

Why the UNO R3  did not communicate  - do I have to boot load it ?

Posted by: @mr-owl

Why the UNO R3  did not communicate  - do I have to boot load it ?

I don't think so, R3's come ready to roll.   Have you tried a simple blink test with one LED or even its on board LED if it has one?  Also you could try a simple hello world program.  If these pass then your new board should be OK, otherwise I suggest you return it from whence it came as DOA.  

@byron   Simple test   UNO R3 Why did I not think of that  - will do . I'll keep the old uno in place for now 

Also notice that going thru the code  under Controls LCD Variables  ;  constant variable  rs  = 15 and en = 14  however the Uno schematic  has them wired into  A1 and A0  and I can't recognize where A1, A0 are identified in the code  ( maybe obvious to  someone who has more programming skills than me ) - see attached - don't know the rationale here .

In the meantime I'll wait for my new LCD Display 

Thanks for your interest 

Posted by: @mr-owl

I can't recognize where A1, A0 are identified in the code

The analogue pins A0, A1 etc can also be used as digital pins in which case they get digital pin numbers 14, 15 etc.  See the attached uno pin out diagram for the alternative pin numbers.

Thanks for all the help , Byron 

Yes, I found it after I asked the question  (GPIO 14, 15 )

 Also did "ping" test on the UNO R3 's - they are okay . Now I'll wait for the New LCD display and hope We resolved the issues 

Back to  DB1 -cable building 

Just another thing to look for, the LCD can have issues if the contrast adjustment is not working right, make sure the pot works and has a good connection.

I also agree that it might be best to "build up" portions of the program to test parts of the whole (try lighting an LED, using the buttons, etc, getting the screen to work alone) and then try to tie it together.