Cosmic_Pi_PSU_Control

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+//Cosmic Pi Power supply open loop controller
+//sets a value to the PSU and then increments it every n seconds.
+
+//MAX1923 chip, with the following resistor values for feedback:
+//R6 = 25k
+//R5 = 200k
+//R8 = 10k
+
+//the old routine has been amended to fix the endian type (now correct)
+
+//Default power up value is FF
+//readback isn't supported and there's no external or integral temp feedback
+//Pin 42 needs to be manually modified for the connection on V2 Alpha main boards
+
+//Set the initial value
+//reduce the value by 1 every 10 seconds
+//voltage ramps slowly up to maximum (about 36V) and then rolls over
+//note that 00 = DC/DC step up power off - i.e. no value output, input rail.
+//The MAX1932 is powered from the 5V rail and accepts commands at 3.3V without problems.
+
+//set up the pins to remap SPI by hand
+const int SS_pin = 42; //tbc
+const int SCK_pin = 44;
+const int MISO_pin = 22;
+const int MOSI_pin = 43;
+
+
+//Define the sending variable
+byte sendValue = 0xFF;   // Value we are going to send
+byte returnValue = 0;  // Where we will store the value sent by the slave
+
+void setup()
+{
+  digitalWrite(SS, HIGH);  // Start with SS high
+  pinMode(SS_pin, OUTPUT);
+  pinMode(SCK_pin, OUTPUT);
+  pinMode(MISO_pin, INPUT); //this is the avalanche pin, not implemented yet
+  pinMode(MOSI_pin, OUTPUT);
+  Serial.begin(9600);
+}
+
+void loop()
+{
+
+//write the value to console
+//send the value
+//decrement the variable and wait 10s before looping
+  
+Serial.println(sendValue, HEX);
+returnValue = bitBang(sendValue); // Transmit data
+sendValue = sendValue-1;
+
+delay(10000);
+}
+
+
+
+byte bitBang(byte _send)  // This function is what bitbangs the data
+{
+
+  //reception isn't implemented in this version. 
+  byte _receive = 0;
+   digitalWrite(SS_pin, LOW);        // SS low 
+  for(int i=0; i<8; i++)  // There are 8 bits in a byte
+  {
+    digitalWrite(MOSI_pin, bitRead(_send, 7-i));    // Set MOSI
+    //delay(1);
+    digitalWrite(SCK_pin, HIGH);                  // SCK high
+    //bitWrite(_receive, i, digitalRead(MISO_pin)); // Capture MISO
+    digitalWrite(SCK_pin, LOW);                   // SCK low
+  //digitalWrite(MOSI_pin, LOW);    // Set MOSI
+    
+  }
+   digitalWrite(SS_pin, HIGH);       // SS high again 
+ 
+  //return _receive;        // Return the received data
+}