ESP32 Node with OLED Display

[papa]

            ESP32 Node with OLED Display, Introduction

A 0.96 inch SSD1306 OLED display is a nice ESP32 board accessory. The I2C method is used to communicate with the OLED via an SDA pin & a SCL pin.

The easiest way may be to get an ESP32 board with hard-wired OLED, like HiLetgo OLED ESP32. On this board, SDA is pin 5 & SCL is pin 4. This is the board I have.

Or get an separate OLED with I2C communication protocol to connect to your ESP32 Board. Such an OLED has four pins to connect: Vin (ESP32 3.3v), GND (ESP32 GND), SDA, & SCL. If pins 4 & 5 are usable on your board, connect OLED SDA to ESP32 pin 5 & SCL to pin 4. See here for other possible pins.

Disclosure: I have a hard-wired OLED, not a separate OLED board.

        Next, Software & Initial Customization

[papa]

                    ESP32 OLED Node

            Software & Initial Customization

Use this thread for the latest software & initial customization.

        Also the Arduino IDE needs to load an OLED software library....

In Arduino IDE, open Tools/Manage Libraries... Search for & install "ESP8266 and ESP32 Oled Driver for SSD1306 display"

            Next, ESP32 OLED Node Customization

[papa]

            ESP32 OLED Node Customization

In the software sketch, deactivate #define lines from previous nodes (have // at line's start).

        Change the nodeId if you have another node with that ID.

In the software sketch, find & activate these #define lines (delete // at the start):

        // #define ENABLE_SSD1306
        // #define I2C_SDA 5
        // #define I2C_SCL 4
If you connect SDA & SDL to different pins, change the 2nd & 3rd lines accordingly.

Upload the customized software to the ESP32 board.

                Next, Expected results

[papa]

                ESP32 OLED Node, Expected results

For topics, the IDE Serial Monitor will show only RSSI & the board's IP address.

Note, like many computer things, OLED display coordinates start counting up from zero.

        When the node boots up, the first OLED screen will show:
msg01 = "OLED 0.0"; // OLED screen 1, line 0
msg02 = "OLED 0.1"; // line 1, IP address for a while, then blank

        Then the next screen will show:
msg05 = "OLED 1.0"; // line 0
msg06 = "OLED 1.1"; // Screen 2, line 1
msg07 = "OLED 1.2" ; // Screen 2, line 2
msg08 = "OLED 1.3" ; // line 3

Then the OLED display alternates between the first & second screens.

To see how the OLED programming works, search for ifdef ENABLE_SSD1306

            Next, ESP32 & OLED, Other Possibilities

[papa]

            ESP32 & OLED, Other Possibilities

Other customization you might do for now: Put your own text into msg02 & msg05-msg08. Pay attention to the length of those variables.

        Options to be documented later:

- openHAB can command different messages for the OLED display.

- PIR presence status can be shown on the OLED display.