Wiring the ST7735R TFT LCD to the imx233-Olinuxino-Micro – II

Now that you've recharged your batteries let's proceed and connect our display.

Let's start by wiring the ST7735. You can read more information about the ST7735 in the datasheet controller/driver chip.

As you can see in the picture this LCD uses Serial Peripheral Interface bus (SPI): MISO, SCLK, MOSI and CS pins are used for SD card communication; SCL, SDA, RS/DC, and CS pins - 4-lines/8-bts bi-directional interface - for communication between the micro controller and the LCD driver.

The imx233-Olinuxino-Micro pinout can be found in the user's manual, chapter 6. Page 32 also provides a reference to a pinout summary made by David Whittaker, which is quite useful.

Here is how we did it:

LCD pin Olimex pin GPIO Function
SCL (SCK) CON2#11 GPIO#24 Serial CLock - Clock pulses which synchronize data transmission generated by the master
SDA (MOSI) CON2#10 GPIO#20 Serial DAta (input/output) - (MOSI Master Out Slave In) - Master line for sending data
RS/DC CON1#17 GPIO#6 RS/DC data/command flag
RES CON1#16 GPIO#5 Reset
CS CON1#13 GPIO#2 Chip Select (SS - Slave Select) - enables (like a switch) communication access to device.

Then connect VCC to +3.3V and GND to ground.

[MISO -> CON2#9 (GPIO#0)  (Master In Slave Out) - Slave line for sending data to the master. NOTE: we did not connect this one, at least for now.]

Now, recheck your wires and then feed your imx233.

Connect

ssh <user>@<computer>

Login by entering  username and password [defaulf should be usr: root, pass: root].

Next, you will need to enable the display module named fbtft_device, which was made available in the kernel in the previous post. [NOTE: the driver names this display adafruit18.]

modprobe fbtft_device name=adafruit18 cs=2 gpios=reset:5,dc:6,led:7 busnum=1

You can confirm that the module for this display was loaded by entering:

lsmod

Likely you'll need to install "something" to help you viewing your images using the linux framebuffer console. We use frame buffer imageviewer (fbi). [Some linux distributions name it fbida.]

apt-get install fbi

Now you are ready to play!

fbi -T 1 -a <filename, ex bla.jpg>

HAVE FUN!

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