Overview

It's the size of your thumbnail, with glorious 160x80 pixel color... it's the Adafruit Mini TFT Breakout! This very very small display is only 0.96" diagonal, packed with RGB pixels, for making very small high-density displays.

The display uses 4-wire SPI to communicate and has its own pixel-addressable frame buffer, it can be used with every kind of microcontroller. Even a very small one with low memory and few pins available!

The breakout has the TFT display soldered on (it uses a delicate flex-circuit connector) as well as a ultra-low-dropout 3.3V regulator and a 3/5V level shifter so you can use it with 3.3V or 5V power and logic. We also had a little space so we placed a microSD card holder so you can easily load full color bitmaps from a FAT16/FAT32 formatted microSD card. The microSD card is not included, but you can pick one up here.

Of course, we wouldn't just leave you with a datasheet and a "good luck!" - we've written a full open source graphics library that can draw pixels, lines, rectangles, circles, text and bitmaps as well as example code and a wiring tutorial. The code is written for Arduino but can be easily ported to your favorite microcontroller!

Specifications:

  • 0.96" diagonal LCD TFT display
  • 160x80 resolution, 16-bit color
  • 4 wire SPI digital interface - SCK, MOSI, CS and DC pins.
  • Built-in microSD slot - uses 2 more digital lines
  • 5V compatible! Use with 3.3V or 5V logic
  • Onboard 3.3V @ 150mA LDO regulator
  • 1 white LED backlight, transistor connected so you can PWM dim the backlight
  • 0.1" pitch header for easy breadboarding
  • 2 removable mounting holes in corners
  • Current draw is based on LED backlight usage: with full backlight draw is ~25mA

Pinouts

This color display uses SPI to receive image data. That means you need at least 4 pins - clock, data in, tft cs and d/c. If you'd like to have SD card usage too, add another 2 pins - data out and card cs. However, there's a couple other pins you may want to use, lets go thru them all!

  • 3-5V / Vin - this is the power pin, connect to 3-5VDC - it has reverse polarity protection but try to wire it right!
  • 3.3V - this is the 3.3V output from the onboard regulator
  • GND - this is the power and signal ground pin
  • CLK - this is the SPI clock input pin. Use 3-5V logic level
  • MISO - this is the SPI Master In Slave Out pin, its used for the SD card. It isn't used for the TFT display which is write-only. It is 3.3V logic out (but can be read by 5V logic)
  • MOSI - this is the SPI Master Out Slave In pin, it is used to send data from the microcontroller to the SD card and/or TFT. Use 3-5V logic level
  • TFT_CS - this is the TFT SPI chip select pin. Use 3-5V logic level
  • RST - this is the TFT reset pin. Connect to ground to reset the TFT! Its best to have this pin controlled by the library so the display is reset cleanly, but you can also connect it to the Arduino Reset pin, which works for most cases. There is an automatic-reset chip connected so it will reset on power-up. Use 3-5V logic level
  • D/C - this is the TFT SPI data or command selector pin. Use 3-5V logic level
  • SD Card CS / SDCS - this is the SD card chip select, used if you want to read from the SD card. Use 3-5V logic level
  • Lite - this is the PWM input for the backlight control. It is by default pulled high (backlight on) you can PWM at any frequency or pull down to turn the backlight off. Use 3-5V logic level

Assembly

The board comes with all surface-mount components pre-soldered. The included header strip can be soldered on for convenient use on a breadboard or with 0.1" connectors. You can also skip this step and solder on wires.

Prepare the header strip:

Cut the strip to length if necessary. It will be easier to solder if you insert it into a breadboard - long pins down

Add the breakout board:

Place the breakout board over the pins so that the short pins poke through the breakout pads

And Solder!

Be sure to solder all 5 pins for reliable electrical contact.

(For tips on soldering, be sure to check out our Guide to Excellent Soldering).

You're done! Check your solder joints visually and continue onto the next steps

Wiring & Test

Basic Graphics Test Wiring

Wiring up the display in SPI mode is pretty easy as there's not that many pins! We'll be using hardware SPI, but you can also use software SPI (any pins) later. Start by connecting the power pins

  • 3-5V Vin connects to the microcontroller 5V pin
  • GND connects to Arduino ground
  • CLK connects to SPI clock. On Arduino Uno/Duemilanove/328-based, thats Digital 13. On Mega's, its Digital 52 and on Leonardo/Due its ICSP-3 (See SPI Connections for more details)
  • MISO is not connected
  • MOSI connects to SPI MOSI. On Arduino Uno/Duemilanove/328-based, thats Digital 11. On Mega's, its Digital 51 and on Leonardo/Due its ICSP-4 (See SPI Connections for more details)
  • CS connects to our SPI Chip Select pin. We'll be using Digital 10 but you can later change this to any pin
  • RST is not connected
  • D/C connects to our SPI data/command select pin. We'll be using Digital 8 but you can later change this pin too.

For the level shifter we use the CD74HC4050 which has a typical propagation delay of ~10ns

Install Adafruit ST7735 TFT Library

We have example code ready to go for use with these TFTs. It's written for Arduino, which should be portable to any microcontroller by adapting the C++ source.

Two libraries need to be downloaded and installed: first is the Adafruit_ST7735 library (this contains the low-level code specific to this device), and second is the Adafruit GFX Library (which handles graphics operations common to many displays we carry). If you have Adafruit_GFX already, make sure its the most recent version since we've made updates for better performance

Download both ZIP files, uncompress and rename the folders to Adafruit_ST7735 (contains Adafruit_ST7735.cpp and .h) and Adafruit_GFX (contains Adafruit_GFX.cpp and .h) respectively. Then place them inside your Arduino libraries folder and restart the Arduino IDE. If this is all unfamiliar, we have a tutorial introducing Arduino library concepts and installation.

Restart the IDE!

After restarting the Arduino software, you should see a new example folder called Adafruit_ST7735 and inside, an example called graphicstest. Look for the lines as follows:

  // Use this initializer if you're using a 1.8" TFT
  tft.initR(INITR_BLACKTAB);   // initialize a ST7735S chip, black tab

  // Use this initializer (uncomment) if you're using a 1.44" TFT
  //tft.initR(INITR_144GREENTAB);   // initialize a ST7735S chip, black tab

  // Use this initializer (uncomment) if you're using a 0.96" 180x60 TFT
  //tft.initR(INITR_MINI160x80);   // initialize a ST7735S chip, mini display

comment out the first line, and uncomment the third, so it looks like:

  // Use this initializer if you're using a 1.8" TFT
  //tft.initR(INITR_BLACKTAB);   // initialize a ST7735S chip, black tab

  // Use this initializer (uncomment) if you're using a 1.44" TFT
  //tft.initR(INITR_144GREENTAB);   // initialize a ST7735S chip, black tab

  // Use this initializer (uncomment) if you're using a 0.96" 180x60 TFT
  tft.initR(INITR_MINI160x80);   // initialize a ST7735S chip, mini display

Now upload the sketch to your Arduino. You may need to press the Reset button to reset the arduino and TFT. You should see a collection of graphical tests draw out on the TFT.

Changing Pins

Now that you have it working, there's a few things you can do to change around the pins.

If you're using Hardware SPI, the CLOCK and MOSI pins are 'fixed' and cant be changed. But you can change to software SPI, which is a bit slower, and that lets you pick any pins you like. Find these lines:

// Option 1 (recommended): must use the hardware SPI pins
// (for UNO thats sclk = 13 and sid = 11) and pin 10 must be
// an output. This is much faster - also required if you want
// to use the microSD card (see the image drawing example)
Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS,  TFT_DC, TFT_RST);
 
// Option 2: use any pins but a little slower!
#define TFT_SCLK 13   // set these to be whatever pins you like!
#define TFT_MOSI 11   // set these to be whatever pins you like!
//Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS, TFT_DC, TFT_MOSI, TFT_SCLK, TFT_RST);

Comment out option 1, and uncomment option 2. Then you can change the TFT_ pins to whatever pins you'd like!

The 0.96" TFT has a auto-reset circuit on it so you probably dont need to use the RST pin. You can change

#define TFT_RST    9

to

#define TFT_RST   -1

so that pin isn't used either. Or connect it up for manual TFT resetting!

Adafruit GFX library

The Adafruit_GFX library for Arduino provides a common syntax and set of graphics functions for all of our TFT, LCD and OLED displays. This allows Arduino sketches to easily be adapted between display types with minimal fuss…and any new features, performance improvements and bug fixes will immediately apply across our complete offering of color displays.

The GFX library is what lets you draw points, lines, rectangles, round-rects, triangles, text, etc.

Check out our detailed tutorial here http://learn.adafruit.com/adafruit-gfx-graphics-library It covers the latest and greatest of the GFX library!

Drawing Bitmaps

There is a built in microSD card slot into the breakout, and we can use that to load bitmap images! You will need a microSD card formatted FAT16 or FAT32 (they almost always are by default).

Its really easy to draw bitmaps! Lets start by downloading this image of ADABOT

Notice its rotated because the screen is 'naturally' portrait but we want the image to be landscape

Copy minibot.bmp into the base directory of a microSD card and insert it into the microSD socket in the breakout.

Two more wires are required to interface with the onboard SD card:

  • You'll need to connect up the MISO pin to the SPI MISO line on your microcontroller. On Arduino Uno/Duemilanove/328-based, thats Digital 12. On Mega's, its Digital 50 and on Leonardo/Due its ICSP-1 (See SPI Connections for more details)
  • Also, SDCS pin to Digital 4 on your Arduino as well. You can change this pin later, but stick with this for now.

You may want to try the SD library examples before continuing, especially one that lists all the files on the SD card

Open the file->examples->Adafruit_ST7735->spitftbitmap example

Edit the setup() intialization to:

  // Use this initializer if you're using a 1.8" TFT
  //tft.initR(INITR_BLACKTAB);   // initialize a ST7735S chip, black tab

  // Use this initializer (uncomment) if you're using a 1.44" TFT
  //tft.initR(INITR_144GREENTAB);   // initialize a ST7735S chip, black tab

  // Use this initializer (uncomment) if you're using a 0.96" 180x60 TFT
  tft.initR(INITR_MINI160x80);   // initialize a ST7735S chip, mini display

And the drawBmp() routine to:

// change the name here!
  bmpDraw("minibot.bmp", 0, 0);

Upload to the Arduino & you will see ADABOT appear!

To make new bitmaps, make sure they are less than 160 by 80 pixels and save them in 24-bit BMP format! They must be in 24-bit format, even if they are not 24-bit color as that is the easiest format for the Arduino. You can rotate images using the setRotation() procedure

You can draw as many images as you want - dont forget the names must be less than 8 characters long. Just copy the BMP drawing routines below loop() and call

bmpDraw(bmpfilename, x, y);

For each bitmap. They can be smaller than 160x80 and placed in any location on the screen.

Downloads

Schematics and Fabrication Print

For the level shifter we use the CD74HC4050 which has a typical propagation delay of ~10ns