But today I’m going to modify it to display its output on two displays, temperature on one and humidity on the other.This doesn’t sound too difficult until you realize that the OLED displays I’ll be using have fixed I2C addresses. %�쏢 Building an I2C Slave – Learning how to run an Arduino as either an I2C master or slave and building a custom I2C sensor. The result was what you might have expected – both displays showed the same image.This actually might come in handy if you wanted to put two identical displays on your project. I2C Address conflicts can occur when you have two I2C slave devices with the same fixed address. It has its own I2C address of 0x70, which can be changed using three pins. You'll be up and running in 15 minutes or less. same I2C addresses devices are used; So we write the SoftwareI2C library to use digit port and analog port to enable multiple same I2C addresses devices work on Arduino. And all of its external I2C connections are 5-volt tolerant and respond to both 3.3-volt and 5-volt logic.This means that you can have multiple I2C buses attached to the device and have different logic-levels on those busses.In this example we are using a 5-volt microcontroller to supply 5-volts to the TCA9548A. I’m going to show you how to do it with an easy-to-use module that will cost you less than 10 dollars.The device we require is a Multiplexer, which is essentially an electronic switching device. 2. I2C Communication Protocol I2C has a master/slave protocol. El bus I2C fue desarrollado por Philips al inicio de la década de 1980, teniendo en mente todos estos aspectos, y ha encontrado una gran aceptación en el mercado. Simple I2C control Up to 8 on a single I2C bus with adjustable address pins 0.25°C typical precision over -40°C to 125°C range (0.5°C guaranteed max from -20°C to 100°C) 0.0625°C resolution It uses one of the AM2320 temperature and humidity sensors I recently featured in my article about In the original sketch, I displayed both temperature and humidity on a single OLED display. It’s a basic rule of I2C – every slave device needs to have a unique address.Some slave devices, like displays or sensors, have configurable I2C addresses. It uses the pins on the Arduino which are dedicated to I2C, so for example on the Arduino Uno it uses pin A4 as SDA and A5 as SCL.For all of its great features, it has some shortcomings – Wire does not allow you to have multiple I2C buses, you can only call one instance of it and you can’t redirect your I2C traffic to different pins.If you want to use multiple I2C buses on the Arduino without any additional hardware then you’ll need to use an alternate library for I2C. The easiest way to resolve this situation is by adding another I2C bus to your design. It operates a lot like a “switch”, changing the multiplexer to direct the data out a specific channel until told otherwise.The function assumes that the multiplexer has a base address of 0x70, which it will if you don’t modify it using the A0-A2 pins.
wrote a lovely little library for Arduino that will work with any Arduino compatible. You could use any two output channels, they are all the same.Note the use of pullup resistors on the display side. But if you wanted to address each display independently you’re out of luck.If the slave devices are sensors or require two-way communication with the host then this situation is unworkable. In Arduino Uno / Nano / Pro Mini I2C bus is connected to A4 (SDA) and A5 (SCL), for Arduino Mega 2560 I2C bus is connected to D20 (SDA) and D21 (SCL) Here I am going to show you how to scan I2C address with a simple code. Build your own Electronics, IoT, Drones and Robots – Welcome to the Workshop!Comments about this article are encouraged and appreciated. Such as the Arduino. ����@f[c���G(�an5�c���"{�l���vv�\k��t���T���$J"}�J�v_+1��&�j�7�t���*�����m�ڄm��ދ��ZҜkd�1�-\Y��g���=�PO�ڤ[�\`y1��ઍ�W�Ja���Vr6Qk��4�6K��L���m��J5~OL;����~v�0:�n �3��2 Arduino I2C Pins.