# ST7735 Readme

[![Donate](https://img.shields.io/badge/Donate-PayPal-green.svg)](https://www.paypal.com/paypalme/whitelight976)

![ ig ](https://github.com/gavinlyonsrepo/pic_16F18346_projects/blob/master/images/st7735/pcb.jpg)

## Table of contents

* [Overview](#overview)
* [Test](#test)
* [Software](#software)
  * [User Options](#user-options)
* [Hardware](#hardware)
* [Output](#output)

## Overview

* Name: ST7735
* Description:

C++ Raspberry pi PICO  library for a TFT SPI LCD, ST7735 Driver

## Test

There are example files included. User picks the one they want
by editing the CMakeLists.txt :: add_executable(${PROJECT_NAME}  section.
Comment in one path and one path only.

| Filename | Function | Note |
| --- | --- | --- |
| hello | Hello world for 128x128 display | --- |
| hello_80x160 | Hello world for 80x160 display | note offsets |
| hello_128x160 | Hello world for 128x160 display | --- |
| text | Text  + fonts | --- |
| graphics | Graphics | --- |
| functions_fps | Functions(like rotate, scroll) + FPS tests | --- |
| bmp_data | 1,8 & 16 bit bitmaps tests + bitmap FPS tests | Bitmap data is stored in arrays on PICO |
| demos | A demo showing a gauge | --- |
| frame_buffer | Testing frame Buffer mode | dislib16_ADVANCED_SCREEN_BUFFER_ENABLE must be enabled user option 2 |

## Software

### User Options

In the main.cpp example files. There are four sections in "Setup()" function
where user can make adjustments to select for SPI type used, PCB type used and screen size.

0. USER OPTION 0 SPI_SPEED + TYPE
1. USER OPTION 1 GPIO
2. USER OPTION 2 SCREEN SECTION
3. USER OPTION 3 PCB_TYPE

#### USER OPTION 0 SPI SPEED

Here the user can pass the SPI Bus freq in kiloHertz, Currently set to 8 Mhz.
Max SPI speed on the PICO is 62.5Mhz.
There is a file with SPI test results for the FPS tests in extra/doc folder.
2nd parameter is the SPI interface(spi0 spi1 etc).

If users wants software SPI just call this method
with just one argument for the optional GPIO software uS delay,
which by default is zero. Setting this higher can be used to slow down Software SPI
which may be beneficial in  some setups.

#### USER OPTION 1 GPIO

The 5 GPIO pins used, the clock and data lines must be the clock and data lines
of spi interface chosen in option 0 if using hardware SPI.

#### USER OPTION 2 Screen size  + Offsets

In the main.cpp file, in USER OPTION 2 .
User can adjust screen pixel height, screen pixel width and x & y screen offsets.
These offsets can be used in the event of screen damage or manufacturing errors around edge
such as cropped data or defective pixels.
The function TFTInitScreenSize sets them.

#### USER OPTION 3 PCB Version

Select your PCB controller type by passing an enum type to function  TFTInitPCBType.
Default is "TFT_ST7735R_Red".  If you select the wrong one if may still work but with wrong colors. BGR instead of RGB.

| Number | Description | Enum label | Tested on |
| ---- | ---- | --- | --- |
| 1 | ST7735B controller | TFT_ST7735B | n/a |
| 2 | ST7735R Green Tab | TFT_ST7735R_Green | n/a |
| 3 | ST7735R Red Tab | TFT_ST7735R_Red | Red PCB v1.1, 1.44 inch , 128x128 pixels |
| 4 | ST7735S Black Tab | TFT_ST7735S_Black | Red PCB v1.2, 1.8 inch, 128x160 pixels |
| 5 | ST7735S 80x160 | TFT_ST7735S_80160 | Blue PCB .96 inch 80x160 pixels |

The ST7735S 80x160 requires an offset of (26,1) or (24,0)

## Hardware

Connections as setup in main.cpp  test file.

| TFT PinNum | Pindesc | HW SPI |
| --- | --- | --- |
| 1 | LED | VCC |
| 2 | SCLK | GPIO18 |
| 3 | SDA | GPIO19 |
| 4 | A0/DC | GPIO3 |
| 5 | RESET | GPIO4 |
| 6 | SS/CS | GPIO2 |
| 7 | GND | GND |
| 8 | VCC | VCC |

1. NOTE connect LED backlight pin 1 thru a 150R/220R ohm resistor to 3.3/5V VCC.
2. This is a 3.3V logic device do NOT connect the I/O logic lines to 5V logic device.
3. You can connect VCC to 5V if there is a 3.3 volt regulator on back of TFT module.
4. SW SPI pick any GPIO you like , HW SPI SCLK and SDA will be tied to spio interface.
5. Backlight on/off control is left to user.
6. To operate without CS pin: pass -1 as argument for CS pin number in SetupGPIO() function
   and ground the CS pin on device side.

## Output

[![ Demo pic ](https://github.com/gavinlyonsrepo/ST7735_TFT_RPI/blob/main/extra/images/4.jpg)](https://github.com/gavinlyonsrepo/ST7735_TFT_RPI/blob/main/extra/images/4.jpg)
[![ demo pic 2](https://github.com/gavinlyonsrepo/Display_Lib_RPI/blob/main/extra/images/st7735output.jpg)](https://github.com/gavinlyonsrepo/Display_Lib_RPI/blob/main/extra/images/st7735output.jpg)