You can connect multiple devices on the I2C-bus, each device gets an address: This site explains the inner working of the I2C-protocol: You can address 128 devices (= 7bit addressing), from 0 to 127). Manufacturers gives these addresses to there I2C-devices. If the chip on your board is a PCF8574 T, then the I2C-addresses can lay in the range of 0x20 to 0x27. If the chip on your board is a PCF8574 AT, then the I2C-addresses can lay in the range of 0x3F to 0x38. This IO-module has a default I2C-address of 0x27, but you can change it yourself by changing the jumpers A0, A1 and A2 on the board (MARK the reverse order of A0A1A2 => A0A1A2).Į.g. In this picture you see that ‘jumper A0’ is soldered. So the I2C-address for this module is 0x26 or 0x3E. The library, called “ LiquidCrystal_I2C.h“, needed for these modules to work, can be found here.In the following example-code, there are 2 I2C-modules used with 2 different LCD-displays (16×2 and 20×4 display), also found partly in the LiquidCrystal_V1.2.1.zip.Ĭheck first if libraries aren’t available in the arduino-ide, before you download them.(Mark! Github always add ‘-master’ when you download a zip-file, unzip, rename the directory without ‘-master’, zip again and import the zip in arduino-ide).

LiquidCrystal_I2C lcd1(0x20,16,2) // set the LCD address of the first lcd to 0x20 It can be used with the same functions as in “LiquidCrystal”, only initialisation of the LCD-object is different.

LiquidCrystal_I2C lcd(0x20,16,4) // set the LCD address of the first lcd to 0x20Ĭonnecting your I2C-module to an Arduino via SDA and SCLīoth modules use the I2C bus, which makes connection very easy. If you’re using an Pro Mini-compatible the pins are A4 and A5 for data and clock, which are parallel to the main pins, as shown below: If you’re using an Arduino Mega the pins are D20 and D21 for data and clock: On Arduino Uno or compatible boards, these pins are A4 and A5 for data and clock: Moving on – first you will need to identify which pins on your Arduino or compatible boards are used for the I2C bus – these will be knows as SDA (or data) and SCL (or clock). The library to use for this ‘mjkdz’-module is “ LiquidCrystal_I2C.h” and can be found here: Other I2C-modules are available, like the ‘mjkds’-module: #WIRE H LIBRARY ARDUINO DOWNLOAD PRO#

Mark the same name for the library, but initialisation is a bit different.And, would you mind taking a look at my code? I have the rc-car example code working well with my spark and motor shield. I have installed a robot arm and hand to my car, but haven’t quite gotten any servos to work.

Wire h arduino library download zip