LPC804 UART

[jeremygeslin]

Running the different UART examples I'm able to send and receive characters with a terminal from a PC (connected over VCOM port).

However, from LPC804, I can only receive characters one by one. If I send, from the PC, a frame of several bytes only the first bytes is properly received (the UART IRQ seems to only be raised on the first byte) thus I'm missing the rest of the frame.

Is it possible to receive several bytes in a raw on LPC804 UART ?

[nxf58474 · Accepted solution]

Hi Jeremy,

I checked the SDK examples, and the problem is the time it takes for the terminal to send characters and characters, it is too fast for the LPC to process and read another byte. I added 1 msec / char delay and it works and I was able to copy a whole paragraph in the terminal. Could you please try the same. Let me know your results.

  

Regards,

Ricardo Zamora

[jeremygeslin]

Hi,

Unfortunately this is not a suitable solution from my side. I understand the limitation from LPC804 if it doesn't include a kind of DMA system allowing to receive the whole frame from the serial interface then letting the FW handle bytes per bytes.

Regards,

Jeremy.

[nxf58474]

Hi Jeremy,

I apologize if I confused your question. Being able to use the DMA helps in the speed of data reception, but it is not the case of the LPC804, as it does not have this module.

The SDK examples for LPC804 are very specific to use, such as the transfer_ring_buffer example, which will be sent by UART until the 8 characters are received, or the polling example, in which you send the character after receiving it. These examples are to be used as a reference, so in order to receive more than one character it is important to consider the changes to be made in your application. In addition please make sure that your serial terminal is configured correctly as that could also limit how the communication is viewed even if via UART it is sent correctly.

Please let me know if you have further questions.

Regards,

Ricardo