Introduction to TTGO T Controller

Currently, this blog post summarizes my first impressions and steps with this module. I will update this post with more code and examples later.

The Hardware
The Software

The Hardware

You can get the module via https://www.aliexpress.com/item/32970371816.html

It contains the following components:

ESP32-WROVER-B 🔎_google Module
SSD1306 128X64 0.96” OLED Display (21=SDA, 22=SCL)
a 5-way Joystick (32="up", 33="down", 34="center", 36="left", 39="right")
(guess) Silergy Corp SY8089AAAC 🔎_google
- 2A continuous step down regulator
- with a quiescent current of 55uA.
(guess) NanJing Top Power ASIC Corp TP5400 🔎_google
- 1000mAh Lipo Charger
- 5V Step up regulator (1A)
- The quiescent current is at 40uA
- The Datasheet is in chinese, so theses properties are guesses
- It has a standby LED and a charge LED (which blinks when there is no Li-Ion battery present)
18650 Li-Ion battery holder on the back

Top view, from left to right: powery circuitry, OLED, Joystick, ESP32

Bottom view, the 18650 holder

The ESP32 module.

The charger/boost component (above green LED), and the drop down regulator (to the right of the green LED)

The Software

Flashing

These are the settings I used to flash the device.

Provided Example

TTGO provided an example on GitHub: https://github.com/LilyGO/TTGO-T-Lion-T18V2.2-/blob/master/T18_V2.2/adc.ino.

Simple Example

As I’m not a fan of complicated smoke tests (i.e. having to install too many libraries to get it to work), I shortened it to:

#include <Arduino.h>

#include "SSD1306.h"
#define SSD1306_ADDRESS 0x3c
#define I2C_SDA 21
#define I2C_SCL 22
SSD1306 oled(SSD1306_ADDRESS, I2C_SDA, I2C_SCL);

void setup()
{
  Serial.begin(115200);
  oled.init();
  oled.flipScreenVertically();
  oled.setFont(ArialMT_Plain_16);
  oled.setTextAlignment(TEXT_ALIGN_CENTER);
  delay(50);

  oled.clear();
  oled.drawString(oled.getWidth() / 2, oled.getHeight() / 2, "TTGO");
  oled.display();
}

void loop()
{
  delay(100);
}

You should get something like this.

Using u8g2

When using the u8g2 library you will need to use the following constructor:

U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, 21, 22);

Note, I had to provide the SDA/SCL pins diretly via the constructor, otherwise only half the display was drawn.

A minimal working example would be:

#include <Arduino.h>
#include <U8g2lib.h>
#include <Wire.h>

U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, 21, 22);

void setup(void) {
  // init display
  u8g2.begin();
}

void loop(void) {
  u8g2.clearBuffer();         // clear the internal memory
  u8g2.setFont(u8g2_font_ncenB08_tr); // choose a suitable font
  u8g2.drawStr(0,10,"Hello World!");  // write something to the internal memory
  u8g2.sendBuffer();          // transfer internal memory to the display
  delay(1000);
}

I uploaded example code to https://github.com/uvwxy/ttgo-t-controller-u8g2 which demonstrates this module using the u8g2 library (https://github.com/olikraus/u8g2).

See below for the result:

Click to open in a new window.

Media ID: B0MbFRnFGFk

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