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lpit_adc

lpit_adc#

Overview#

The lpit_adc example shows how to use LPIT to generate ADC triggers. On top of the basic counter, to use the ADC trigger, simply enable the “milestone” of the ADC trigger and set it with a user-defined value. When the LPIT counter is on, when the count passes the “milestone”, a pre-trigger of the ADC is generated and sent to the ADC module. In this example, the ADC is configured with hardware triggering and conversion complete interrupt enabled. Once it gets a trigger from the LPIT, the transition occurs and then the ISR is executed.

Supported Boards#

MIMXRT1180-EVK
Hardware requirements

  • Mini/micro USB cable

  • MIMXRT1180-EVK board

  • Personal Computer

Board settings

  • ADC CH7A input signal J41-2(GPIO_AD_02).

Prepare the Demo

  1. Connect a USB cable between the host PC and the OpenSDA USB port on the target board.

  2. Open a serial terminal with the following settings:

    • 115200 baud rate

    • 8 data bits

    • No parity

    • One stop bit

    • No flow control

  3. Download the program to the target board.

  4. Either press the reset button on your board or launch the debugger in your IDE to begin running the demo.

Running the demo

When the demo runs successfully, the log would be seen on the OpenSDA terminal like:

LPADC Interrupt Example
ADC Full Range: 4096
Full channel scale (Factor of 1).
ADC interrupt count: 1
ADC value: 572
ADC interrupt count: 2
ADC value: 575

The analog voltage input range is theoretically 0-1.8V. However, due to the workaround for ERR051152, the maximum voltage should be limited to 1.78V. Due to the errata051385, the ADC reference voltage is connect to the VDDA_ADC_1P8.

FRDM-IMXRT1186
Hardware requirements

  • Type-C USB cable

  • FRDM-IMXRT1186 board

  • Personal Computer

Board settings

Change Jumper J27 from 1-2 to 2-3

  • ADC CHA1 input signal J51-8(GPIO_AD_14).

Prepare the Demo

  1. Connect a USB cable between the host PC and the OpenSDA USB port on the target board.

  2. Open a serial terminal with the following settings:

    • 115200 baud rate

    • 8 data bits

    • No parity

    • One stop bit

    • No flow control

  3. Download the program to the target board.

  4. Either press the reset button on your board or launch the debugger in your IDE to begin running the demo.

Running the demo

When the demo runs successfully, the log would be seen on the OpenSDA terminal like:

LPADC Interrupt Example
ADC Full Range: 4096
Full channel scale (Factor of 1).
ADC interrupt count: 1
ADC value: 572
ADC interrupt count: 2
ADC value: 575

The analog voltage input range is theoretically 0-1.8V. However, due to the workaround for ERR051152, the maximum voltage should be limited to 1.78V. Due to the errata051385, the ADC reference voltage is connect to the VDDA_ADC_1P8.

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