SPI communication with MAX3421E Problem with data

Projects Programming
1

Hello everyone,

I am trying to communicate with a MAX3421E.
However I have a problem with the SPI communication.
I have a class that is handling all the communication with the MAX3421E and it is "mostly" working.
Writting on the IC itself works perfectly, but reading data from it is more problematic

void Maxima::Register_Read(byte Command_Byte)
{
  Serial.print("Read ");
  Serial.print("Command Byte:");
  Serial.print(Command_Byte, BIN);  
  Serial.print(" ");
  SPI.beginTransaction(_mySettings);
  digitalWrite(_ss,LOW);
  SPI.transfer(Command_Byte);
  _miso_data=SPI.transfer(0x00);
  _miso_data=_miso_data |0b00000000;
  digitalWrite(_ss, HIGH);
  SPI.endTransaction();
  Serial.print("Data:");
  Serial.println(_miso_data, BIN);
}

Here is the output I recieve:

Serial Output:
Register:20Read Command Byte:10100000 Data:11110000
Register:21Read Command Byte:10101000 Data:11110000
Register:22Read Command Byte:10110000 Data:0
Register:23Read Command Byte:10111000 Data:0
Register:24Read Command Byte:11000000 Data:0
Register:25Read Command Byte:11001000 Data:1000
Register:26Read Command Byte:11010000 Data:0
Register:27Read Command Byte:11011000 Data:11000001

I tried to do:
_miso_data=_miso_data | 0b00000000;
But it doesn't change the Output. I want to force _miso_data to include all the bits and not only bits after a first "1". I thought about using ShiftIn(), but it doesn't really make me happy since I would be working with arrays and then I have to convert back and forth all the time, because I will be using a lot of bit operations.
Does someone have an elegant solution for this? All suggestions would be very much welcomed. Thank you!

2

I want to force _miso_data to include all the bits and not only bits after a first "1"

What does this mean? If the value in _miso_data is 1, are you expecting to see 00000001 printed?

If so, that is an unrealistic expectation. If you expect that, you need to write your own procedure for outputting a byte in binary format.

The default in every programming language it to not print useless leading zeros.