I finally got the LCD screen to run properly from the Python library in the tutorials.
I can't say I had to change anything. I did have to adjust the voltage (err contrast? brightness?) on with the potentiometer on the back of the LCD. It was set either too high or too low. I thought I had adjusted it before, but apparently everything wasn't lined up. This last time around, I had SCL plugged into 19 and SDA into 20. I will go sit in a corner later.
Changes to the Tutorial that I had to discover.
- opkg install ca-bundle (to install the certificate bundle to let git work right)
- The script I used above to help me find the right address, but the address was the same as in the documentation from the gentleman who made the library.
- The script fails if you don't add the address.
python lcd.py --line1="HELLO WORLD" --line2="LET FREEDOM RING!" --address=0x3f
is what worked for me.
- Adjusting the brightness with the blue Trim Pot (Trimming potentiometer) after something has been written to the screen.
Hope this helps someone. I ran around in circles for quite awhile.