1.2 ADC Low Power

This example application shows the different low power sleep modes available with Fast Wake up either enabled or disabled.

Description

Conversion of the AD6 analog input is triggered from software trigger at every 500 ms. Sleep mode is enabled and ADC core is OFF between conversions. Reference voltage circuitry is either On or Off between conversions depending on FWUP values. Analog input voltage in the range of 0 V to 3.3 V is fed to the ADC input channel AD6. Sleep mode is enabled and Fast Wake up value is selected. ADC conversion result is displayed on the console.

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/adc/adc_low_power_mode/firmware .

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

Project NameDescription
sam_9x75_curiosity.XMPLABX project for SAM9X75 Curiosity Development Board

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.

Project NameDescription
sam_9x75_curiosity.XSAM9X75 Curiosity Development Board

Setting Up SAM9X75 Curiosity Development Board

  • Connect the UART DEBUG J35 on board to the computer using a UART-FTDI cable (to enable debug com port)
  • Connect the USB port J2 on board to the computer using a micro USB cable (to power the board)
  • AD6 pin is used for analog input
  • Use a jumper wire to connect Pin AN of mikroBUS (AD6 is mapped to Port Pin PA31) to 3.3 V or GND

Running the Application

  1. Build the application using its IDE
  2. Open the Terminal application (Ex.:Tera term) on the computer.
  3. Connect to the (USB to Serial) COM port and configure the serial settings as follows:
    • Baud : 115200
    • Data : 8 Bits
    • Parity : None
    • Stop : 1 Bit
    • Flow Control : None
  4. The console asks to choose FWUP value, Press 0 or 1.
    • Observe ADC entering sleep mode with Fast Wake up OFF/ON. Console displays the ADC Count and the ADC Input Voltage
    Fast Wake up OFF
    Fast Wake up ON