![]() ![]() This is a very long time for higher-performance chip such as ATSAM3X and is often critical for time-sensitive application such as robotic control. However, the communication can take up to 1ms for a MPU9250 simple sensor read. The behavior is adapted for almost all MPU IMU driver for Arduino I can find online. The default Wire library in Arduino always reads and writes to the I2C bus in a blocking fashion. ![]() This library allows the microcontroller to run other tasks concurrently, while waiting for the I2C communications to complete. If you have difficulty setting up I2C communication between different devices, don’t hesitate to leave us a comment or contact us.Arduino Due non-blocking I2C communication library using PDC (peripheral DMA controller)Īn Arduino Due with a ATSAM3X8E ARM Cortex-M3 CPU has the capability of using its hardware Peripheral DMA Controller (PDC, DMA=Direct Memory Access) to handle I2C communication without user intervension. Wire.onRecieve () manages the data reception functionĬode of the “Master” card #include # define I2C_SLAVE1_ADDRESS 11 # define I2C_SLAVE2_ADDRESS 12 #define PAYLOAD_SIZE 2 int n = 0 void setup ( ).Wire.onRequest () handles the request receive function. ![]() Wire.endTransmission ends data transmission.Wire.beginTransmission () starts transmitting data and defines the receiver.Wire.requestFrom () handles the request receive function.Wire.write () allows you to send bytes.Function argument may be empty for master devices Wire.begin () initializes the device address.The functions are similar to the Serial library. ![]() The Wire.h library allows you to easily define the serial communication on the I2C bus. Generally, one card will send information (Writer) and another will receive it (Reader). In order for the two cards to communicate with each other, they must be connected correctly (A4 with A4 and A5 with A5) and do not forget to connect the earths (GND) as shown in the following diagram.Ĭaution: If pins A4 and A5 are connected to the pins of a non-powered card, the code will freeze at the time of transmission. In this example we use an Arduino Uno board, so the pins A4 and A5. One on which the data is sent (SDA Serial Data Line) and on the other the synchronization clock (SLC Serial Clock Line). The pins used by I2C communication are usually fixed for each device. For that, we have to write at least two programs, one for the “Mistress” card (Master) and the other for the “Slaves” cards.Īn I2C communication is defined by a two-wire bus (sometimes called TWI, Two Wire Interface) and an address. An interesting example is the communication between several Arduino boards. With the I2C protocol, it is also possible to communicate between different systems (sensors, LCD screen, Raspberry Pi, etc.).
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