Wiring

NOTE: There are two interfaces on the 2.8" TFT breakout, a 8-bit parallel interface and a SPI serial interface. This guide uses the SPI serial interface--make sure you connect your development board to the SPI interface side of the breakout! You'll also need to either connect the IM0 IM1 and IM2 pins to 3V or close the solder jumpers on the back!

Raspberry Pi

Wire you TFT breakout to a Raspberry Pi as follows:

Make these connections with jumper wires:

  • Raspberry Pi 3.3V power to TFT Vin.
  • Raspberry Pi ground to TFT GND.
  • Raspberry Pi SCLK to TFT CLK.
  • Raspberry Pi MOSI to TFT MOSI.
  • Raspberry Pi CE0 to TFT CS.
  • Raspberry Pi GPIO 18 to TFT D/C.
  • Raspberry Pi GPIO 23 to TFT RST.
  • TFT 3Vo to TFT IM3, IM2, and IM1 - These connections will put the display in SPI mode and are optional if you've bridged the display jumpers to permanently put the display in SPI mode.

Most Raspberry Pi's should have SPI enabled already, but if yours doesn't make sure you've enabled SPI access on the Raspberry Pi. To check if SPI is enabled you should see a /dev/spidev0.0 and /dev/spidev0.1 devices if you run the command ls /dev/spi* in a terminal on the Pi.  

If you don't see these devices then follow the steps here to run raspi-config, but instead of enabling I2C select the SPI option to enable the SPI access on the Raspberry Pi.  Then follow that up by updating the kernel module blacklist to make sure the SPI module is commented out and not blacklisted.  After making the changes reboot your Pi and run the ls command above again to be sure you can see the /dev/spidev0.0 and /dev/spidev0.1 devices before continuing!

BeagleBone Black

Wire your TFT breakout to the BeagleBone Black as follows:
Make these connections with jumper wires (if you aren't familiar with pin numbers on the BeagleBone Black, check out this guide for more information):
  • BeagleBone Black 3.3V power pin P9_3 to TFT Vin.
  • BeagleBone Black ground pin P8_2 to TFT GND.
  • BeagleBone Black SCLK pin P9_22 to TFT CLK.
  • BeagleBone Black MOSI pin P9_18 to TFT MOSI.
  • BeagleBone Black CE0 pin P9_17 to TFT CS.
  • BeagleBone Black pin P9_15 to TFT D/C.
  • BeagleBone Black pin P9_12 to TFT RST.
  • TFT 3Vo to TFT IM3, IM2, and IM1 - These connections will put the display in SPI mode and are optional if you've bridged the display jumpers to permanently put the display in SPI mode.
Like with the Raspberry Pi, the wiring above assumes using a hardware SPI interface on the BeagleBone Black, specifically /dev/spidev1.0. Before you can use this SPI interface you must enable a device tree overlay to turn on the SPI pin functionality. The easiest way to enable this device tree overlay is to configure the BeagleBone Black to load the overlay automatically on boot.

With the BeagleBone Black connected to your computer over USB, open the USB mass storage drive named 'boot' and edit the file uEnv.txt on the drive. Add the following line to the file:

optargs=capemgr.enable_partno=BB-SPIDEV0

NOTE: Be careful editing the uEnv.txt file on Windows, as changing the line endings can cause your BeagleBone Black not to boot and require an OS reinstall! The safest option is to connect to the BeagleBone Black in a command window and follow the steps at the end of this page to mount and edit uEnv.txt on the BeagleBone Black.

Reboot your device and you should see the files /dev/spidev1.0 and /dev/spidev1.1 now exist.
Last updated on 2015-05-04 at 04.27.56 PM Published on 2014-07-30 at 03.40.06 PM