mruby-esp32-i2c

I2C library for mruby-esp32.

Installation

Add the line below to your build_config.rb:

  conf.gem :github => 'mruby-esp32/mruby-esp32-i2c'

Example

Example of controlling the LCD display with ST7032 controller.

Demo movie

Code

include ESP32
class ST7032
  def initialize(i2c, addr=0x3e, cols=8)
    @i2c = i2c
    @addr = addr
    @cols = cols
  end
  def init
    # see controller data sheet
    @i2c.send("\x00\x38\x39\x14\x70\x56\x6c", @addr)
    System.delay(200)
    @i2c.send("\x00\x38\x0c\x01", @addr)
    System.delay(1)
  end
  def ready?
    @i2c.ready?(@addr)
  end
  def contrast(n)
    c1 = (0x70 | (n & 0x0f)).chr
    c2 = (0x54 | (n >> 4) & 0x03).chr
    @i2c.send(["\x00\x39", c1, c2, "\x38"].join, @addr)
  end
  def clear
    @i2c.send("\x00\x01", @addr)
  end
  def print(str)
    clear
    @i2c.send("\x00\x80", @addr)
    @i2c.send(["\x40", str[0,@cols]].join, @addr)
    if str.length > @cols
      @i2c.send("\x00\xc0", @addr);
      @i2c.send(["\x40", str[@cols,@cols]].join, @addr)
    end
  end
end
i2c = I2C.new(I2C::PORT0).init(I2C::MASTER)
p i2c.scan
lcd = ST7032.new(i2c)
until lcd.ready?
  System.delay(1000)
end
lcd.init
lcd.print("Hello, world!")
System.delay(3000)
(0..63).each {|c|
  lcd.contrast(c)
  lcd.print("c=#{c}")
  System.delay(100)
}
lcd.contrast(32)
lcd.clear
i2c.deinit

mruby-esp32-i2c-ssd1306 - OLED SSD1306 (I2C) library for mruby-esp32
mruby-esp32-i2c-bme280 - BME280 (I2C) library for mruby-esp32

License

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the “Software”),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.