TWIHS EEPROM read write

This example application shows how to use the TWIHS peripheral to write and read from the I2C serial EEPROM memory.

Description

This example uses the TWIHS peripheral library to write an array of values to the I2C Serial EEPROM and verify the value written by reading the values back and comparing it to the value written.

Downloading and building the application

To clone or download this application from Github, go to the main page of this repository and then click Clone button to clone this repository or download as zip file. This content can also be downloaded using content manager by following these instructions.

Path of the application within the repository is apps/twihs/master/twihs_eeprom/firmware .

To build the application, refer to the following table and open the project using its IDE.

Setting up AT91Bootstrap loader

To load the application binary onto the target device, we need to use at91bootstrap loader. Refer to the at91bootstrap loader documentation for details on how to configure, build and run bootstrap loader project and use it to bootstrap the application binaries.

Setting up the hardware

The following table shows the target hardware for the application projects.

Setting up SAMA5D2 Xplained Ultra Evaluation Kit

Setting up the board

• Short jumper JP2 (DEBUG_DIS)
• Connect the Debug USB port on the board to the computer using a micro USB cable
• If this application is used for communicating with apps/twihs/slave/i2c_eeprom_emulation application, then connect TWIHS SDA line on Pin 7 (PD4) of J22 connector and TWIHS SCL line on Pin 8 (PD5) of J22 connector with the corresponding SDA and SCL lines of the TWIHS slave.

Running the Application

1. Open the main.c file and make sure the following macro is defined to true when communicating with on-board EEPROM and to false when communicating with the apps/twihs/slave/i2c_eeprom_emulation application.

   When communicating with on-board EEPROM:

   #define I2C_SLAVE_IS_ONBOARD_EEPROM true

   When communicating with apps/twihs/slave/i2c_eeprom_emulation application

   #define I2C_SLAVE_IS_ONBOARD_EEPROM false

2. Build the application using its IDE

3. The LED indicates the success or failure:

   • The LED is turned ON when the value read from the EEPROM matched with the written value
   • The LED is turned OFF when the value read from the EEPROM did not match with the written value

Refer to the following table for LED name:

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