dac_continuous_pit_dma#
Overview#
The demo shows how to use the PIT to generate a DAC trigger and use the DMA to transfer data into DAC buffer.
In this example, DAC is first set to normal buffer mode. PIT is as DAC hardware trigger source and DMA would work when DAC read pointer is zero. When run the example, the DAC is triggered by PIT and the read pointer increases by one, every time the trigger occurs. When the read pointer reaches the upper limit, it goes to zero directly in the next trigger event. While read pointer goes to zero, DMA request will be triggered and transfer data into DAC buffer. The user should probe the DAC output with a oscilloscope to see the Half-sine signal.
Supported Boards#
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 CONTINUOUS PIT DMA DEMO
Please probe the DAC output with a oscilloscope.
Then user can probe the DAC output with a oscilloscope to see the Half-sine signal.
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 CONTINUOUS PIT DMA DEMO
Please probe the DAC output with a oscilloscope.
Then user can probe the DAC output J6-2 with a oscilloscope to see the Half-sine signal.