create unsigned char array to get the spi data from ADC , which is connected through usb to SPI converter to matlab

i am using a 24 bit ADC with SPI output, i need to interface it to MATLAB so im using MCP2210( usb to SPI converter working)

my board working and i am able to configure it.

Problem.... To receive SPI data from pc(matlab)<-converter<-ADC, i need to use TxferSpiData function in .dll of mcp2210.

below i have shown Coding in C++ to tx and Rx two 8-bit data.

how can i create this array in matlab to receive 27 bytes of data in 27 array(8 channel ADC of 24 bit resolution) , i have used cell to receive it not working.

i have added my code.m and Guide to use MCP2210 TxferSpiData function( page no 16) *

out = gcnew array<unsigned char>(2) {0x00,0x00};

in = gcnew array<unsigned char>(2) {0x00, 0x00};
intret = UsbSpi->Functions->TxferSpiData(out, in);

how to create a unsigned char array (similar to c++ code above in matlab) to receive this data into matlab with TxferSpiData function in dll. Guide page no:16

https://docs.google.com/file/d/0Bws2MsjT5CWcMkZWM3FNN2lGamc/edit?usp=sharing

Thanks & Regards

Ikram khan.S.I

Answer 1

[Walter Roberson]

Receive unsigned char as uint8(), and then if necessary char() it to convert to characters.

[ikram khan]

thanks for the replay... i need to get array of 27 bytes using TxferSpiData function used in .Dll of usb to SPI converter.

each time i call this function i will receive 27 bytes of data,so i need a array of unsigned char as per c++ code in last message.

Info given in converter datasheet

Name: TxferSpiData

Purpose: Transfer the specified SPI data Parameters:

Inputs: dataTx (array<Byte>^) - Array of SPI data to send to device. This array should be at least the same size as numBytes or larger.

 *Outputs*: dataRx (array<Byte>^) – Array that contains SPI data received. This array should be at least the same size as numBytes or larger. 
Returns:
 int - Return value:
 negative = error
 0 = success

in last msg i have shown code in c++ to use TxferSpiData function. how to do the same in matlab.

sorry for my poor English.

Thanks & Regards

Ikram khan.S.I

[Walter Roberson]

buffer = uint8(28,1);
success = TxferSpiData(buffer);
if success == 0
  spi_chars = char(buffer(1:27));
else
  fprintf('TxferSpiData returned error: %d\n', success);
end