Those photos are dreadful! (And posted as attachments instead of in-line links. Makes things difficult with this current (per)version of the forum software.)
int backLight = 13; // pin 13 will control the backlight
It occurred to me that it may have been a back-light washing out the text issue during my first attempt and so I thought I would drop the voltage over the resistor to attempt to dim the light.
Well, that is simply not going to happen. You cannot “wash out” the LCD display with the backlight.
On pin 3 that 220ohm resistor I think was an error of judgement. The text shows the same with or without it.
Well, no. This is the contrast resistor - the best value will generally be between zero and 1k but clearly the text is perfectly visible as things are. There may be little difference between zero and 220 ohms but one will be better than the other.
What I found a bit unusual, and I’m sure there is a good reason for it, is that on the back of the LCD it shows the pins 1-16 left to right but also shows a number 16 on the left of the pins and a number 1 on the right confusingly.
Looks perfectly correct to me. I think you were getting confused. Pin 1 is nearest the end of the board.
His reasoning is OK. The resistor on pin 13 is current limiting for the LED which may not be needed but too much resistance is better than too little.
It is indeed not needed - if we could only see R8, I am quite sure we would observe it marked as “101”. It seems Harpertooned actually realised that already as well as:
The resistor on pin 3 goes to GND if he followed the photo in the tutorial. It is the replacement for the potentiometer that you so frequently recommend.
He got that right! The other problem was the confusion of Pin 3 on the LCD being Vo, the contrast voltage, and pin 13 on the Arduino which was actually connected to pin 15 on the LCD.
I have looked at the photos and agree with what was posted in reply #4. You have D4 and D5 reversed. Did you happen to notice how neatly the wires were arranged in that tutorial?
Well, got that sorted. But following the wires in those terrible photos was mind-bending or eye-crossing.
In terms of neat wiring, what he needs to do is to get some more of those “Dupont” male-to-female wires and rather than separating them all, break out some groups including the the black-brown-red as three, some other groups of three, four and five, then get some of the two, three, four and five-way housings from eBay - generally only a dollar or two per hundred so you can afford to get ridiculous quantities - and make up nice little ribbons for connections.
Generally you will want the wires in order, but you may also want certain transpositions for particular applications. The single housings can be removed intact with reasonable care (and the smallest jeweller’s screwdriver in the set) and saved for potential re-use.
If you separate the black-brown-red or black-brown-red-orange then you can have the black and red in a two-pin housing and the brown as a single (or brown and orange as singles) If you simply swap red and brown in a three pin housing you have of course, a “standard” servo or sensor cable (though what is usually used for servos is brown-red-orange as it is not necessary to perform the swap; the brown becomes the ground).