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adc_polling

adc_polling#

Overview#

The SAR ADC polling example shows the simplest way to use the SAR ADC driver.

In this example, three channels (channel 0, 1, and 2) are used to form a conversion chain, these three channels are executed in the normal conversion one-shot mode. The end-of-channel interrupt, pre-sample, DMA transfer, and watchdog features of each channel in the conversion chain are disabled. The user should provide a voltage signal to each conversion channel. When running the project, type any key into the debug console to get these three channels’ conversion result, if the result of the channel conversion is valid, it will be printed to the debug console.

Supported Boards#

IMX943-EVK
Hardware requirements

  • Personal Computer

  • IMX943EVK board

  • 12V~20V power supply

  • J-Link Debug Probe

  • Micro USB cable

Board settings

Set 0~3.3V voltage input to below ADC channels by using DC power supply ADC channel 4(J9-2) ADC channel 5(J9-5) ADC channel 6(J9-8)

Connect J43-12 to oscilloscope to capture the trigger signal.

Please note this application can’t support running with Linux BSP!
Prepare the Demo

  1. Connect the 12V~20V power supply and J-Link Debug Probe to the board, and switch SW4 to power on the board.

  2. Connect a micro USB cable between the host PC and the J31 USB port on the target board.

  3. Open a serial terminal with the following settings:

    • 115200 baud rate

    • 8 data bits

    • No parity

    • One stop bit

    • No flow control

  4. Download the program to the target board.

  5. Either re-power up your board or launch the debugger in your IDE to begin running the example.

Running the demo

When the example runs successfully, you will see similar information from the terminal shown below. You will also capture the trigger signal on OSC after ADC value get.

 IPSYNC trigger signal connected to output

 ADC polling example.
 Please press any key to get the conversion result.
 The channel 4 ADC conversion data is 4084.
 The channel 5 ADC conversion data is 3740.
 The channel 6 ADC conversion data is 2049.
 Please press any key to get the conversion result.
 The channel 4 ADC conversion data is 4085.
 The channel 5 ADC conversion data is 3741.
 The channel 6 ADC conversion data is 2049.
 Please press any key to get the conversion result.
 The channel 4 ADC conversion data is 4084.
 The channel 5 ADC conversion data is 3739.
 The channel 6 ADC conversion data is 2049.
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