[RTL8722CSM] [RTL8722DM] I2C - Send and Receive

Materials

  • AmebaD[AMB21 / AMB22] x 1

  • Arduino UNO x 1

Steps

I2C is a very common module on microcontrollers, it only takes 2 wire and able to achieve data rate at up to 3.4Mbps. It works in master-slave model and a master can simultaneously connect to up to 128 slaves, making it a very versatile communication protocol between microcontroller and sensor.

Here we are going to use Ameba as an I2C master and Arduino UNO as a slave to achieve I2C send and recv.

Before connection, make sure to upload the “Examples -> Wire -> Slave_receiver” example code to Arduino UNO.

Connection is shown as follows, here we are using PA_26 as SDA pin and PA_25 as SCL.

Note

There is currently 1 set of I2C available to MicroPython user, they are

Unit

SDA

SCL

0

PA_26

PA_25

image1

Then copy and paste the following code line by line into REPL to see their effects.

1from machine import Pin, I2C
2i2c = I2C(scl = "PA_25", sda = "PA_26", freq=100000) # configure I2C with pins and freq. of 100KHz
3i2c.scan()
4i2c.writeto(8, 123) # send 1 byte to slave with address 8
5i2c.readfrom(8, 6) # receive 6 bytes from slave