Esp8266 + i2c oled

michaltaberski · May 14, 2019, 7:23pm

Hi I am having problem with connecting OLED display via I2C.

My setup

ESP8266 (Wemos D1)
OLED 128x64 SSD1306
wiring:
i2c.sda - GPIO 4 (D2)
i2c.scl - GPIO 5 (D1)

  - ["i2c.enable", true]
  - ["i2c.sda_gpio", 4]
  - ["i2c.scl_gpio", 5]

mos call I2C.Scan detects the display-> [ 60 ].

The code sample I am trying to run is:

github.com

mongoose-os-apps/example-arduino-adafruit-ssd1306-js/blob/master/fs/init.js

/*
 * Copyright (c) 2014-2017 Cesanta Software Limited
 * All rights reserved
 *
 * This example demonstrates how to use mJS Arduino Adafruit_SSD1306
 * library API.
 */

// Load Mongoose OS API
load('api_timer.js');
load('api_arduino_ssd1306.js');

// Initialize Adafruit_SSD1306 library (I2C)
let d = Adafruit_SSD1306.create_i2c(4 /* RST GPIO */, Adafruit_SSD1306.RES_128_64);
// Initialize the display.
d.begin(Adafruit_SSD1306.SWITCHCAPVCC, 0x3D, true /* reset */);
d.display();
let i = 0;

let showStr = function(d, str) {

This file has been truncated. show original

with the difference where I updated I2C address to 0x3c (60)

I was looking for an answer here, but I didn’t find the solution yet - https://forum.mongoose-os.com/discussion/1106/i2c-oled-not-working.

What else can I do? How else can I debug the problem?

I know the I2C display is working fine, because I got it working using different firmware (espruino).

michaltaberski · May 14, 2019, 7:59pm

Ok, I found it. I am new to mongoose, so I made this rookie mistake

Except import libs in JS code init.js file I also should import libs by adding them to mos.yml.

In my particular case those are:

    # libs necessary for the current app
  - origin: https://github.com/mongoose-os-libs/arduino-adafruit-ssd1306
  - origin: https://github.com/mongoose-os-libs/mj