AVR-Based Serial Enabled LCDs Hookup Guide

I am trying to connect the Qwiic cable on the 16x2 SERlcd then connect the other end of the cable to a breadboard with a Raspberry pi PICO. I can get the script to work when I connect from the pins on the board with using the i2C and pwr breakout. I am using the code as displayed in the book “Getting Started with Micron Python on the Raspberry PI PICO”; page 118. When using the Qwiic cable I get power to the LCD and I try using the blue and yellow wires on the connector to power the SDA and SCL on the PICO, I even switched them with the same results. It may be a contrast problem so how can I change the contrast via Micro Python?

Unfortunately we don’t have any micro python example code, but the [serial Arduino code in the hookup guide could be adapted to micro python pretty easily.](https://learn.sparkfun.com/tutorials/avr-based-serial-enabled-lcds-hookup-guide/serial-uart-example-code---contrast-control-with-a-trimpot)

Hi @rockman55 and @TS-Chris ,

I’m trying to do the same as rockman55. Can you tell me what AVR stands for?

The Atmel-based processors use [AVR Technology](AVR microcontrollers - Wikipedia)

Ah thanks @SV-Zanshin . AVR is not an acronym. Atmel is the important thing to know the name of.

TS-Chris:
Unfortunately we don’t have any micro python example code, but the [serial Arduino code in the hookup guide could be adapted to micro python pretty easily.
[/quote]
Can you check out the example on page 118 of the “Getting Started With Micro Python on the Raspberry Pi PICO”. They are using the PICO with the Sparkfun SerLCD 16x2 using a Micro Python script. I have run this script but now I cannot see the screen because the contrast is off. I run your example “Serial UART: Example Code - Contrast Control with a Trimpot” and set the contrast to 0, then reran the Micro Python script again but still cannot see the text because the contrast is off. Is there some other way to control the contrast on the Sparkfun SerLCD?](https://learn.sparkfun.com/tutorials/avr-based-serial-enabled-lcds-hookup-guide/serial-uart-example-code---contrast-control-with-a-trimpot)

When you run “Serial UART: Example Code - Contrast Control with a Trimpot”, are you doing that on an Arduino? Does anything display on the screen while you’re running that sketch?

A contrast of 0 might be too low for your display, does setting it to 40 make it work?

TS-Chris:
When you run “Serial UART: Example Code - Contrast Control with a Trimpot”, are you doing that on an Arduino? Does anything display on the screen while you’re running that sketch?

A contrast of 0 might be too low for your display, does setting it to 40 make it work?

I used the Arduino code. When running again I could not get the contrast to change, everything seemed ok from the Serial Display but the contrast would not change. I found a very helpful website that showed me some Micro Python code that I could use to change the contrast on the SerLCD ([https://diyodemag.com/projects/playing_ ... ew_project](https://diyodemag.com/projects/playing_with_raspberry_pi_pico_review_project)).