SPI Tx & Rx failure

RE: SPI Tx & Rx failure

Ree Wang — Fri, 09 Mar 2018 04:17:46 GMT

Hi,

Yes. I see Transfer complete... I find some mistake in my Arduino SPI slave code. I have updated, then it can receive data from nRF52 DK. Transfer from master to slave is working well now. But still not working for slave to master.

Since this questions of this ticket is solved, I would like to close it. I have create another ticket for slave to master transfer issue.

devzone.nordicsemi.com/.../spi-master-cannot-receive-spi-slave-response

Thank you very much for your help!

RE: SPI Tx & Rx failure

Jørgen Holmefjord — Thu, 08 Mar 2018 14:48:04 GMT

Do you still see "Transfer completed." on the RTT terminal from the nRF52840? You did connect slave select line to Arduino as well? Could you write exact pins connected from what to what (SS, SCK, MISO, MOSI)?

RE: SPI Tx & Rx failure

Ree Wang — Thu, 08 Mar 2018 09:52:10 GMT

I am using nRF52480 Preview Development Kit. When I send more than one bytes, for example:

uint8_t tx_data[] = {5,1};
uint8_t dummy_receive[] = {0,0};
APP_ERROR_CHECK(nrf_drv_spi_transfer(&spi, tx_data, 2, dummy_receive, 2));

I still could not see the log in Arduino side.

Below is arduino code I am used. The original code can be find in the link: https://arduino.stackexchange.com/questions/16348/how-do-you-use-spi-on-an-arduino


// what to do with incoming data
volatile byte command = 0;

void setup (void)
  {
  Serial.begin(9600);
  // have to send on master in, *slave out*
  pinMode(MISO, OUTPUT);

  // turn on SPI in slave mode
  SPCR |= _BV(SPE);

  // turn on interrupts
  SPCR |= _BV(SPIE);

  }  // end of setup


// SPI interrupt routine
ISR (SPI_STC_vect)
  {
  byte c = SPDR;

  if (command==1)

      SPDR = c -5;  
      Serial.print("rx:);
      Serial.println(c, Hex); 
      break;

  }  // end of interrupt service routine (ISR) SPI_STC_vect

void loop (void)
  {

  // if SPI not active, clear current command
  if (digitalRead (SS) == HIGH)
    command = 0;
  else command = 1;
  }  // end of loop

RE: SPI Tx & Rx failure

Jørgen Holmefjord — Thu, 08 Mar 2018 09:32:37 GMT

I tested with P1.12-P1.15 pins as well and I'm still seeing data being transmitted. Have you tried sending more bytes? What does the Arduino SPI slave expect? Will it print logs on any data received? Do you have a link to the code of the Arduino example? I would really recommend getting a logic analyzer for debugging issues like this.

RE: SPI Tx & Rx failure

Ree Wang — Thu, 08 Mar 2018 09:20:24 GMT

Thanks!

I connected nRF DK and Arduino Uno. I flashed Arduino with a Arduino SPI Slave program. I run nRF SDK spi on nRF DK, I see the Arduino print the log when nRF DK transfer data to Arduino. However, when I run my code, Arduino doesn't print log.

I don't have a logic analyzer...

In Arduino board, the SPI pins are 10,11,12,13. Corresponding to nRF52840 Preview DK, they are p1.12, p1.13, p1.14,

RE: SPI Tx & Rx failure

Jørgen Holmefjord — Thu, 08 Mar 2018 08:58:12 GMT

Hi,

I treied your code and can see data being output on MOSI line. How are you seeing that the Arduino does not receiving the data? Have you checked the SPI bus lines using a logic analyzer, to see if anything is sendt?

Note this errata if you are using Eng A revision of nRF52840, with a single byte being sendt using SPI (with EasyDMA enabled).

[quote user=""] I modified the PIN according to Arduino PIN[/quote]

Which pins did you use?

Best regards,
Jørgen