SparkFun 16x2 SerLCD + Pico

My son has got interested in electronics and coding so I bought him a Pico and the basic configuration book. I have tried to attach the SparkFun LCD to the pico as shown in the following diagram.

When I first did this I was able to create all sorts of text from scrolling to zigzag… I then removed the connections and gave it to my son to give it a go, he plugged it in as per the diagram and now I cannot seem to get it working?

Is it hard to short these screens? I am able to get it to power on if place VBUS into CL and GRN into DA or VBUS into DA and GRN into - but for the life of me can no longer print text?

Any suggestions?


Hi Andrew,
Welcome to the forum :slight_smile:

If you are concerned about the physical connection of the device I can see that the SparkFun 16x2 SerLCD is part of their Qwiic range of devices, these are I2C devices that run at 3.3V and are fitted with JST SH 4pin connectors. The STEMMA QT range from Adafruit, and our own PiicoDev line all will work together with the same connectors and fittings.
You could simplify the connection for your son and remove the chance of miss-wiring with our PiicoDev adapter for Pi Pico and a cable using the connector on the back of the display.

As for troubleshooting your current setup, thanks for including your diagrams, could you include a photo just in case we can spot anything out of place?


Hey @Andrew160950
I don’t recommend connecting VBUS to CL and GND to DA - this is applying power directly to a data bus. It’s possible this could have cooked the microcontroller on the LCD module.
VBUS must go to RAW, and GND must go to (-) as in the diagram.

Can you reply with the source for that image? It might help us troubleshoot any other factors that might be at play.


Hi Trent,

Soldering is half the fun. I soldered the header pin onto the screen and the Pico.
Image taken before soldering header pins - shows it was all working. Was also working after header pins soldered. Since then screen does not display.

Image in post before was taken from Get Started with MicroPython on Raspberry Pi Pico

Chapter 10 Page 116.

This is the screen now - just blank.



Hi Andrew,

It’s a little hard to tell from your photo how your ground connect is wired to the Pico. Is there the usual 1 pin gap between the top VBUS rail and the ground?
Otherwise, it looks like you have wired it correctly this time so I can only assume the unit may have been damaged as Michael suggested and even wiring it correctly now may not bring it back to life.