There isn’t much going into the project, and I’ve miniaturized it where possible. Mainly, instead of using an Arduino Uno, I’ll use the Arduino Pro Mini microcontroller. While not entirely necessary, I’m adding a buck converter between the power source and the microcontroller.

 

Components

Microcontroller and Voltage Regulation

The Arduino Pro Mini has its own voltage regulator, but in the event of a power spike, I’m putting in a DC step down voltage regulator (LM2596) between the 12v input and the Arduino Pro Mini. SparkFun is the creator of the Arduino Pro Mini, and has this to say about its power intake:

The Arduino Pro Mini can be powered with an FTDI cable or breakout board connected to its six pin header, or with a regulated 3.3V or 5V supply (depending on the model) on the Vcc pin. There is a voltage regulator on board so it can accept voltage up to 12VDC. If you’re supplying unregulated power to the board, be sure to connect to the “RAW” pin, not VCC.
The power pins are as follows:
RAW For supplying a raw voltage to the board.
VCC The regulated 3.3 or 5 volt supply.
GND Ground pins.

I can wire the 12v input directly to the Arduino Pro Mini, but in the event of a power spike, it may burn out the microcontroller. Using the LM2596 buck converter, I can ensure that I have 5v of regulated voltage going to VCC on the microcontroller.

 

 

 

 

TFT Display with microSD Reader

Using the same 2.8″ TFT display as the motorcycle picture frame project. This is also a picture frame project, and it worked well on the previous project. There is the 8-bit and SPI mode, and I’ll be using SPI as required. From Adafruit’s TFT display product page:

Essentially, the tradeoff is pins for speed. SPI is about 2-4 times slower than 8-bit mode, but that may not matter for basic graphics!

In addition, SPI mode has the benefit of being able to use the onboard microSD card socket for reading images. We don’t have support for this in 8-bit mode so if you want to have an all-in-one image viewer type application, use SPI!

I don’t need the speed for displaying BMP images, and I want to use the built-in microSD card reader for loading the pictures of my dad. Additionally, it’s fewer pins, making the cable management easier overall.