Electronic – arduino – Controlling 23K256 SPI RAM with Arduino

I'm trying to interface with a 23K256 SPI RAM IC using an Arduino Mega 2560. I can't use the standard SPI pins, since I'm using an ethernet shield and it doesn't play nicely when SS is set high.

So, instead, I'm trying to bit-bang it. I've tried a few methods of my own, and eventually borrowed the code from the link in this video's description, but it doesn't seem to work at all.

// hold pin is wired directly to VCC (3.3V)
int RAMClockPin = 14;
int RAMInPin = 15;
int RAMOutPin = 11; 
int RAMSelectPin = 12;

// These are hard-wired in the chip
int RAM_READ_COMMAND = 3;    // 00000011
int RAM_WRITE_COMMAND = 2; // 00000010 

//================================================

// Send a byte into the chip's input, bit by bit
void RAMRawWrite(byte b) {

  // Cycle through the 8 bits in the byte
  for (int j = 0; j < 8; j++) {

     // Send MSB (Most Significant Bit) to chip
     if ((b & 0x80) == 0x80) digitalWrite(RAMInPin, HIGH);
       else digitalWrite(RAMInPin, LOW);
     // Send a clock pulse
     digitalWrite(RAMClockPin, HIGH); 
     digitalWrite(RAMClockPin, LOW); 
     // Shift the rest of the bits, one to the left
     b = b << 1;

   }  

}

//================================================

// The whole procedure of sending a data byte
void writeToRAM(unsigned int wAddr, byte wValue) {

  // Pointer to a byte
  byte *bp;

  // Point to higher byte of address (wAddr is 2 bytes long)
  bp = (byte *)&wAddr + 1;
  // Start session
  digitalWrite(RAMSelectPin, LOW);
  // Send the "write" command
  RAMRawWrite(RAM_WRITE_COMMAND);
  // Send the address, one byte at a time
  RAMRawWrite(*bp); // Higher byte
  bp--;
  RAMRawWrite(*bp); // Lower byte
  // Send the data byte
  RAMRawWrite(wValue);
  // Close session
  digitalWrite(RAMSelectPin, HIGH);   

}

//================================================

// The whole procedure of reading a data byte
byte readFromRAM(unsigned int rAddr) {

  byte b, currBit;
  byte *bp;

  // Point to higher byte of address
  bp = (byte *)&rAddr + 1;
  // Start session
  digitalWrite(RAMSelectPin, LOW);
  // Send the "read" command
  RAMRawWrite(RAM_READ_COMMAND);
  // Send address
  RAMRawWrite(*bp); // Higher byte
  bp--;
  RAMRawWrite(*bp); // Lower byte

  // Get bits, MSB-first
  b = 0;
  for (byte currBit = 0x80; currBit > 0; currBit = currBit >> 1) {

     // Clock signal start
     digitalWrite(RAMClockPin, HIGH); 
     // Get one bit of data, put it in the appropriate place 
     if (digitalRead(RAMOutPin) == HIGH) b += currBit;
     // Clock signal end
     digitalWrite(RAMClockPin, LOW); 

  }  

  // End session and return result
  digitalWrite(RAMSelectPin, HIGH);   
  return b;

}

void setup() {
  Serial.begin(9600);
  pinMode(RAMClockPin, OUTPUT);
  pinMode(RAMInPin, OUTPUT);
  pinMode(RAMOutPin, INPUT);
  pinMode(RAMSelectPin, OUTPUT);  
  digitalWrite(RAMSelectPin, HIGH);

  Serial.println("Writing 0xA3 to 16");
  writeToRAM(16, 0xA3);
  Serial.println("Reading back...");
  byte value = readFromRAM(16);
  Serial.println(value, HEX);
}

void loop() {}

The result of the read is 0x00 every time. I've double and triple checked my pin numbers and tried reversing SI/SO, but it still isn't working. Unfortunately I don't have a scope to test the data.

Any ideas?