Problem compiling ESP32 with SPI

Projects Networking, Protocols, and Devices
1

Dear All,

I am trying to read an SD card using an ESP32 but get an error message from the SPI library. Also when I try the example program from the SPI library I get the same error. I hope someone can help me.

below the error code i get while compiling:

I get this error both in the Arduino IDE (1.8.13) and with Visual Studio

I used this library: GitHub - espressif/arduino-esp32: Arduino core for the ESP32

Error code:

Compiling 'SD_Test' for 'ESP32 Dev Module'
SPI.cpp: In member function void SPIClass::transferBytes(const uint8_t*, uint8_t*, uint32_t)
SPI.cpp: 297:43: error: invalid conversion from 'const uint8_t* {aka const unsigned char*}' to 'uint8_t* {aka unsigned char*}' [-fpermissive]
spiTransferBytes(_spi, data, out, size)
Error compiling libraries
Build failed for project 'SD_Test'
SPI.h:26: In file included from
SPI.cpp:22: from
esp32-hal-spi.h:108: note initializing argument 2 of void spiTransferBytes(spi_t*, uint8_t*, uint8_t*, uint32_t)
void spiTransferBytes(spi_t * spi, uint8_t * data, uint8_t * out, uint32_t size)

I hope you can help me out!

Thanks in advance,
Hugo

2

There is very little chance of being able to provide help unless you post the code that produced the errors

3

Help you out without being able to view the code, not happening.

Oh, CODE TAGS.

Here is how I tranfer data using the ESP32's SPI API:


///////////////////////////////////////////////////////////////
int fReadSPIdata16bits( spi_device_handle_t &h, int _address )
{
  uint8_t address = _address;
    esp_err_t intError = 0;
    low=0; high=0;
    spi_transaction_t trans_desc;
    trans_desc = { };
    trans_desc.addr =  0;
    trans_desc.cmd = 0;
    trans_desc.flags = 0;
    trans_desc.length = (8 * 3); // total data bits
    trans_desc.tx_buffer = txData;
    trans_desc.rxlength = 8 * 2 ; // Number of bits NOT number of bytes
    trans_desc.rx_buffer = rxData;
    txData[0] = address | 0x80;
    intError = spi_device_transmit( h, &trans_desc);
    low = rxData[0]; high = rxData[1];
  return intError;
} // void fSendSPI( uint8_t count, uint8_t address, uint8_t DataT

int fWriteSPIdata8bits( spi_device_handle_t &h, int _address, int _sendData )
{
  uint8_t address =  _address;
  uint8_t sendData = _sendData;
  esp_err_t intError;
  spi_transaction_t trans_desc;
  trans_desc = { };
  trans_desc.addr =  0;
  trans_desc.cmd = 0;
  trans_desc.flags = 0;
  trans_desc.length = (8 * 2); // total data bits
  trans_desc.tx_buffer = txData;
  trans_desc.rxlength = 0 ; // Number of bits NOT number of bytes
  trans_desc.rx_buffer = NULL;
  txData[0] = address  & 0x7F;
  txData[1] = sendData;
  intError = spi_device_transmit( h, &trans_desc);
  return intError;
} // void fWriteSPIdata8bits(  spi_device_handle_t &h, uint8_t address, uint8_t sendData )
//
4

This is the code
SD_Test.ino (5.4 KB)

5

This is the code
SD_Test.ino (5.4 KB)

6

Why not post it here in a reply, using code tags when you do ?

7

Why not post your code?

8

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