dac_buffer_interrupt#
Overview#
The dac_buffer_interrupt example shows how to use DAC buffer with interrupts.
When the DAC’s buffer feature is enabled, user can benefit from the automation of updating DAC output by hardware/ software trigger. As we know, the DAC converter outputs the value of item pointed by current read pointer. Once the buffer is triggered by software or hardware, the buffer’s read pointer would move automatically as the work mode is set, like normal (cycle) mode, swing mode, one-time-scan mode or FIFO mode.
In this example, it captures the user’s type-in operation from terminal and does the software trigger to the buffer. The terminal would also display the log that shows the current buffer pointer’s position with buffer events.
Supported Boards#
FRDM-K22F
Hardware requirements
Mini/Micro USB cable
FRDM-K22F board
Personal Computer
Board settings
No special is needed.
Prepare the Demo
Connect a USB cable between the PC host and the OpenSDA USB port on the board.
Open a serial terminal on PC for OpenSDA serial device with these settings:
115200 baud rate
8 data bits
No parity
One stop bit
No flow control
Download the program to the target board.
Either press the reset button on your board or launch the debugger in your IDE to begin running the demo.
A multimeter may be used to measure the DAC output voltage.
Running the demo
When the demo runs successfully, the log would be seen on the OpenSDA terminal like:
DAC buffer interrupt Example.
DAC Buffer Information Buffer index max : 15 Buffer watermark : 14 Press any key in terminal to trigger the buffer … Buffer Index 0: ReadPointerTopPositionEvent Buffer Index 1: Buffer Index 2: Buffer Index 3: Buffer Index 4: Buffer Index 5: Buffer Index 6: Buffer Index 7: Buffer Index 8: Buffer Index 9: Buffer Index 10: Buffer Index 11: Buffer Index 12: Buffer Index 13: Buffer Index 14: WatermarkEvent Buffer Index 15: ReadPointerBottomPositionEvent
Buffer Index 0: ReadPointerTopPositionEvent Buffer Index 1: Buffer Index 2: Buffer Index 3: …
User can take a look at how the pointer is moved by triggered, then user can also measure the DAC output pin to check responding voltage.
FRDM-K32L2A4S
Hardware requirements
Mini/Micro USB cable
FRDM-K32L2A4S board
Personal Computer
Board settings
No special is needed.
Prepare the Demo
Connect a USB cable between the PC host and the OpenSDA USB port on the board.
Open a serial terminal on PC for OpenSDA serial device with these settings:
115200 baud rate
8 data bits
No parity
One stop bit
No flow control
Download the program to the target board.
Either press the reset button on your board or launch the debugger in your IDE to begin running the demo.
A multimeter may be used to measure the DAC output voltage.
Running the demo
When the demo runs successfully, the log would be seen on the OpenSDA terminal like:
DAC buffer interrupt Example.
DAC Buffer Information
Buffer index max : 15
Buffer watermark : 14
Press any key in terminal to trigger the buffer ...
Buffer Index 0: ReadPointerTopPositionEvent
Buffer Index 1:
Buffer Index 2:
Buffer Index 3:
Buffer Index 4:
Buffer Index 5:
Buffer Index 6:
Buffer Index 7:
Buffer Index 8:
Buffer Index 9:
Buffer Index 10:
Buffer Index 11:
Buffer Index 12:
Buffer Index 13:
Buffer Index 14: WatermarkEvent
Buffer Index 15: ReadPointerBottomPositionEvent
Buffer Index 0: ReadPointerTopPositionEvent
Buffer Index 1:
Buffer Index 2:
Buffer Index 3:
...
User can take a look at how the pointer is moved by triggered, then user can also measure the DAC output pin to check responding voltage.
FRDM-K32L2B
Hardware requirements
Mini/Micro USB cable
FRDM-K32L2B board
Personal Computer
Board settings
No special is needed.
Prepare the Demo
Connect a USB cable between the PC host and the OpenSDA USB port on the board.
Open a serial terminal on PC for OpenSDA serial device with these settings:
115200 baud rate
8 data bits
No parity
One stop bit
No flow control
Download the program to the target board.
Either press the reset button on your board or launch the debugger in your IDE to begin running the demo.
A multimeter may be used to measure the DAC output voltage.
Running the demo
When the demo runs successfully, the log would be seen on the OpenSDA terminal like:
DAC buffer interrupt Example.
DAC Buffer Information Buffer index max : 1 Press any key in terminal to trigger the buffer …
Buffer Index 0: ReadPointerTopPositionEvent Buffer Index 1: ReadPointerBottomPositionEvent
User can take a look at how the pointer is moved by triggered, then user can also measure the DAC output pin to check responding voltage.
FRDM-MCXC444
Hardware requirements
Type-C USB cable
FRDM-MCXC444 board
Personal Computer
Board settings
No special is needed.
Prepare the Demo
Connect a type-c USB cable between the host PC and the MCU-Link USB port (J13) on the target board.
Open a serial terminal with the following settings:
115200 baud rate
8 data bits
No parity
One stop bit
No flow control
Download the program to the target board.
Either press the reset button on your board or launch the debugger in your IDE to begin running the demo.
A multimeter may be used to measure the DAC output voltage.
Running the demo
When the demo runs successfully, the log would be seen on the terminal like:
DAC buffer interrupt Example.
DAC Buffer Information Buffer index max : 1 Press any key in terminal to trigger the buffer …
Buffer Index 0: ReadPointerTopPositionEvent Buffer Index 1: ReadPointerBottomPositionEvent
User can take a look at how the pointer is moved by triggered, then user can also measure the DAC output pin J6-2 to check responding voltage.