adafruit 2.8″ capacitive tft screen

Today’s review is on the small TFT touchscreen for the Raspberry Pi computer. At $45, it’s not the cheapest screen you could add onto a single-board computer but the capacitive touchscreen and the four accompanying tactile pushbuttons along the side make it worth the extra money, especially if you’re adding it to a 3D printer for the sake of control.

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TFT

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Installation

As usual, the Adafruit documentation was more than adequate to get this done. They provide an installation script which makes the process easy.

Observations

The touchscreen works wonderfully, much better than the typical/cheaper resistive TFT that we’re most familiar with.

I’ll need to determine which GPIO pins those four pushbuttons go to. It will be nice to use those in some sort of interface.

I reviewed both the OctoPrint-TFT and TouchUI interfaces for OctoPrint on this. I’m not convinced that either are a perfect fit, given the size of the screen. Both required the Desktop to be installed on Raspbian. In the case of TouchUI, it required the use of a local browser on the Pi (Chromium) but I was able to get this to go into the full screen mode.

Other than as a control interface for a 3D printer, I’m not quite sure what projects would be a good fit for this. The timelapse rail kit would be good for this setup, perhaps. It’s a little bulky for a cryptocurrency cold wallet. It would probably make a good streaming music player, given the positioning of those buttons.

Adafruit makes some very attractive enclosures for this, unfortunately they’re out of stock at the moment.

  • Size: 2.8″ (board matches form factor of Raspberry Pi 3B)
  • Screen dimensions: 50mm x 69mm
  • PCB dimensions: 56mm x 85mm
  • Brand: Adafruit
  • Model: 2423
  • Name: PiTFT Plus 320×240 2.8″ TFT + Capacitive Touchscreen
  • Cost: $45
  • Resolution: 320×240
  • Touchscreen type: capacitive
  • Feature: extra 40-pin header underneath board
  • Feature: four tactile pushbuttons

small screen for the raspberry pi 3

I thought I’d do some prep work for a project that I’d like to finish before the Christmas break:  a time-lapse rail kit for the Nikon D750 DSLR camera. I’ll be going to Arches National Park in Utah for that week and wanted to do some astrophotography and sunset time-lapse videos. Here’s vaguely what the rig will look like:

pi-lapse

This photographer/inventor David Hunt has done a pretty good job on his rig and has produced some stunning videos. I hope to take things up a notch since I have access to a 3D printer and a variety of extruded 80/20 aluminum rails from ActoBotics, for example.

Oh… and the entire rig will need to be portable since I’ll likely be backpacking it into the park. Fortunately, I have a sewing machine and a good supply of marine-grade canvas to create something to hold and carry all of this.

TFT

Fortunately, Fry’s Electronics sells some of what Adafruit has to offer and in this case, it’s a tiny TFT screen with a touchscreen built in. It’s technically called a “Pi Hat” since it connects right to the top of a Raspberry Pi 3, for example.

adafruit-1601

I’ve got it connected to a Raspberry Pi 3 and have inserted a new 4GB microSD card for this project and furthermore, have loaded Raspbian Jessie Lite for that image. Although my version won’t have a nifty graphical desktop like the photo above, it will still run touch-based graphical menus.

Python

Looks like I’ll be using the Python programming language for this project. I’d prefer JavaScript but I only have a few weeks to get this “production-ready”, so to speak.

Kivy

The next step in developing graphical menus which respond to touch is to install the Kivy  framework for Python. The menu should allow you to set some configuration options for the spacing of the photos, the number of photos for the series and things pertinent to stepping the camera along the rail using a motor. Finally, there would be start and stop features for each session as well as on-going status.

Nikon

The Nikon D750 has a remote-shutter system and I’ve managed to find a good third-party version of the cable which should come in handy for this. I’ve spec’d out that interface so I should be able to remotely fire off the camera from the Raspberry computer.

Overall

This should be a fun project. I hope I can finish it in the perhaps five weeks left before Christmas break.