usart_transfer_rb_dma#
Overview#
The usart dma ring buffer example shows how to use usart driver with DMA driver used:
In this example, a ring buffer was implemented to receive the characters from PC side, to implemente the ring buffer, a descriptor was created and chain itself as the next descriptor, then the DMA transfer will start a continuous transfer.
While data in the ring buffer reach 8 characters, routine will send them out using DMA mode.
Supported Boards#
LPCXpresso824MAX
Hardware requirements
Mini/micro USB cable
LPCXpresso824MAX board
Personal Computer
Board settings
Connect SJ9: 2-3
Prepare the Demo
Connect a micro USB cable between the PC host and the CMSIS DAP USB port on the board
Open a serial terminal with the following settings:
9600 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.
Running the demo
The log below shows the output of the hello world demo in the terminal window:
USART DMA ring buffer example
Board will send back received data
LPCXpresso845MAX
Hardware requirements
Mini/micro USB cable
LPCXpresso845MAX board
Personal Computer
Board settings
No special settings are required.
Prepare the Demo
Connect a micro USB cable between the PC host and the CMSIS DAP USB port on the board
Open a serial terminal with the following settings:
9600 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.
Running the demo
The log below shows the output of the hello world demo in the terminal window:
USART DMA ring buffer example
Board will send back received data
LPCXpresso860MAX
Hardware requirements
Micro USB cable
LPCXpresso860MAX board
Personal Computer
Board settings
No special settings are required.
Prepare the Demo
Connect a micro USB cable between the PC host and the CMSIS DAP USB port on the board
Open a serial terminal with the following settings:
9600 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.
Running the demo
The log below shows the output of the hello world demo in the terminal window:
USART DMA ring buffer example
Board will send back received data